Редактирование: CD5

T-cell surface glycoprotein CD5 precursor (Lymphocyte antigen T1/Leu-1) (CD5 antigen) [LEU1]

==Publications==

{{medline-entry
|title=Comparative proteomic analysis identifies biomarkers for renal aging.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/33159023
|abstract=Proteomics have long been applied into characterization of molecular signatures in aging. Due to different methods and instrumentations employed for proteomic analysis, inter-dataset validation needs to be performed to identify potential biomarkers for aging. In this study, we used comparative proteomics analysis to profile age-associated changes in proteome and glutathionylome in mouse kidneys. We identified 108 proteins that were differentially expressed in young and aged mouse kidneys in three different datasets; from these, 27 proteins were identified as potential renal aging biomarkers, including phosphoenolpyruvate carboxykinase (Pck1), [[CD5]] antigen-like protein (Cd5l), aldehyde dehydrogenase 1 (Aldh1a1), and uromodulin. Our results also showed that peroxisomal proteins were significantly downregulated in aged mice, whereas IgGs were upregulated, suggesting that peroxisome deterioration might be a hallmark for renal aging. Glutathionylome analysis demonstrated that downregulation of catalase and glutaredoxin-1 (Glrx1) significantly increased protein glutathionylation in aged mice. In addition, nicotinamide mononucleotide (NMN) administration significantly increased the number of peroxisomes in aged mouse kidneys, indicating that NMN enhanced peroxisome biogenesis, and suggesting that it might be beneficial to reduce kidney injuries. Together, our data identify novel potential biomarkers for renal aging, and provide a valuable resource for understanding the age-associated changes in kidneys.

|keywords=* NMN
* biomarkers
* glutathionylation
* proteomics
* renal aging
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7695359
}}
{{medline-entry
|title=Systemic Inflammation and the Increased Risk of Inflamm-Aging and Age-Associated Diseases in People Living With HIV on Long Term Suppressive Antiretroviral Therapy.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/31507593
|abstract=The ART program in low- and middle-income countries (LMIC) like India, follows a public health approach with a standardized regimen for all people living with HIV (PLHIV). Based on the evidence from high-income countries (HIC), the risk of an enhanced, and accentuated onset of premature-aging or age-related diseases has been observed in PLHIV. However, very limited data is available on residual inflammation and immune activation in the populations who are on first-generation anti-HIV drugs like zidovudine and lamivudine that have more toxic side effects. Therefore, the aim of the present study was to evaluate the levels of systemic inflammation and understand the risk of age-associated diseases in PLHIV on long-term suppressive ART using a large number of biomarkers of inflammation and immune activation. Blood samples were obtained from therapy naïve PLHIV (Pre-ART, [i]n[/i] = 43), PLHIV on ART for >5 years (ART, [i]n[/i] = 53), and HIV-negative healthy controls (HIVNC, [i]n[/i] = 41). Samples were analyzed for 92 markers of inflammation, sCD14, sCD163, and telomere length. Several statistical tests were performed to compare the groups under study. Multivariate linear regression was used to investigate the associations. Despite a median duration of 8 years of successful ART, sCD14 ([i]p[/i] < 0.001) and sCD163 ([i]p[/i] = 0.04) levels continued to be significantly elevated in ART group as compared to HIVNC. Eleven inflammatory markers, including 4E-BP1, [[ADA]], [[CCL23]], [[CD5]], [[CD8A]], [[CST5]], [[MMP1]], NT3, [[SLAMF1]], TRAIL, and TRANCE, were found to be significantly different ([i]p[/i] < 0.05) between the groups. Many of these markers are associated with age-related co-morbidities including cardiovascular disease, neurocognitive decline and some of these markers are being reported for the first time in the context of HIV-induced inflammation. Linear regression analysis showed a significant negative association between HIV-1-positivity and telomere length ([i]p[/i] < 0.0001). In ART-group [[CXCL1]] ([i]p[/i] = 0.048) and TGF-α ([i]p[/i] = 0.026) showed a significant association with the increased telomere length and IL-10RA was significantly associated with decreased telomere length ([i]p[/i] = 0.042). This observation warrants further mechanistic studies to generate evidence to highlight the need for enhanced treatment monitoring and special interventions in HIV-infected individuals.
|mesh-terms=* Adult
* Aging
* Anti-HIV Agents
* Antiretroviral Therapy, Highly Active
* Biomarkers
* CD4 Lymphocyte Count
* Computational Biology
* Cross-Sectional Studies
* Disease Susceptibility
* Duration of Therapy
* Female
* HIV Infections
* Humans
* Inflammation
* Male
* Metabolome
* Metabolomics
* Middle Aged
* Proteomics
* Telomere Homeostasis
* Viral Load
|keywords=* HIV
* India
* LMIC (lower middle income country)
* inflammation markers
* long term antiretroviral therapy
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6718454
}}
{{medline-entry
|title=Crucial Role of Increased Arid3a at the Pre-B and Immature B Cell Stages for B1a Cell Generation.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/30930899
|abstract=The Lin28b Let7  axis in fetal/neonatal development plays a role in promoting [[CD5]]  B1a cell generation as a B-1 B cell developmental outcome. Here we identify the Let7 target, Arid3a, as a crucial molecular effector of the B-1 cell developmental program. Arid3a expression is increased at pro-B cell stage and markedly increased at pre-B and immature B cell stages in the fetal/neonatal liver B-1 development relative to that in the Lin28b Let7  adult bone marrow (BM) B-2 cell development. Analysis of B-lineage restricted Lin28b transgenic (Tg) mice, Arid3a knockout and Arid3a Tg mice, confirmed that increased Arid3a allows B cell generation without requiring surrogate light chain (SLC) associated pre-[[BCR]] stage, and prevents MHC class II cell expression at the pre-B and newly generated immature B cell stages, distinct from pre-[[BCR]] dependent B development with MHC class II in adult BM. Moreover, Arid3a plays a crucial role in supporting B1a cell generation. The increased Arid3a leads higher Myc and Bhlhe41, and lower Siglec-G and [[CD72]] at the pre-B and immature B cell stages than normal adult BM, to allow [[BCR]] signaling induced B1a cell generation. Arid3a-deficiency selectively blocks the development of B1a cells, while having no detectable effect on [[CD5]]  B1b, MZ B, and FO B cell generation resembling B-2 development outcome. Conversely, enforced expression of Arid3a by transgene is sufficient to promote the development of B1a cells from adult BM. Under the environment change between birth to adult, altered [[BCR]] repertoire in increased B1a cells occurred generated from adult BM. However, crossed with B1a-restricted V /D/J IgH knock-in mice allowed to confirm that SLC-unassociated B1a cell increase and CLL/lymphoma generation can occur in aged from Arid3a increased adult BM. These results confirmed that in fetal/neonatal normal mice, increased Arid3a at the pre-B cell and immature B cell stages is crucial for generating B1a cells together with the environment for self-ligand reactive [[BCR]] selection, B1a cell maintenance, and potential for development of CLL/Lymphoma in aged mice.
|mesh-terms=* Aging
* Animals
* B-Lymphocyte Subsets
* DNA-Binding Proteins
* Gene Expression Regulation, Leukemic
* Histocompatibility Antigens Class II
* Leukemia, Lymphocytic, Chronic, B-Cell
* Mice
* Mice, Knockout
* Neoplasm Proteins
* Precursor Cells, B-Lymphoid
* Receptors, Antigen, B-Cell
* Transcription Factors
|keywords=* Arid3a
* B-1 development
* B1a
* CLL/lymphoma
* Lin28b
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6428705
}}
{{medline-entry
|title=Correlation of cell-surface CD8 levels with function, phenotype and transcriptome of naive CD8 T cells.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/30556901
|abstract=We have previously demonstrated co-receptor level-associated functional heterogeneity in apparently homogeneous naive peripheral [[CD4]] T cells, dependent on MHC-mediated tonic signals. Maturation pathways can differ between naive [[CD4]] and naive CD8 cells, so we tested whether the latter showed similar co-receptor level-associated functional heterogeneity. We report that, when either polyclonal and T-cell receptor (TCR)-transgenic monoclonal peripheral naive CD8 T cells from young mice were separated into CD8  and CD8  subsets, CD8  cells responded poorly, but CD8  and CD8  subsets of CD8 single-positive (SP) thymocytes responded similarly. CD8  naive CD8 T cells were smaller and showed lower levels of some cell-surface molecules, but higher levels of the negative regulator [[CD5]]. In addition to the expected peripheral decline in CD8 levels on transferred naive CD8 T cells in wild-type (WT) but not in MHC class I-deficient recipient mice, short-duration naive T-cell-dendritic cell (DC) co-cultures in vitro also caused co-receptor down-modulation in CD8 T cells but not in [[CD4]] T cells. Constitutive pZAP70/pSyk and pERK levels ex vivo were lower in CD8  naive CD8 T cells and dual-specific phosphatase inhibition partially rescued their hypo-responsiveness. Bulk mRNA sequencing showed major differences in the transcriptional landscapes of CD8  and CD8  naive CD8 T cells. CD8  naive CD8 T cells showed enrichment of genes involved in positive regulation of cell cycle and survival. Our data show that naive CD8 T cells show major differences in their signaling, transcriptional and functional landscapes associated with subtly altered CD8 levels, consistent with the possibility of peripheral cellular aging.
|mesh-terms=* Adult
* Animals
* CD8 Antigens
* CD8-Positive T-Lymphocytes
* Cellular Senescence
* Female
* Healthy Volunteers
* Humans
* Male
* Mice
* Mice, Inbred C57BL
* Mice, Transgenic
* Transcriptome
* Young Adult
|keywords=* CD8 T cells
* T-cell transcriptome
* cellular aging
* immune aging phenotype
* tonic signals
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6418459
}}
{{medline-entry
|title=Early Generated B-1-Derived B Cells Have the Capacity To Progress To Become Mantle Cell Lymphoma-like Neoplasia in Aged Mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/29898964
|abstract=In mice, fetal/neonatal B-1 cell development generates murine [[CD5]]  B cells (B1a) with autoreactivity. We analyzed B1a cells at the neonatal stage in a V 11/D/J  knock-in mouse line (V 11t) that generates an autoreactive antiphosphatidylcholine [[BCR]]. Our study revealed that antiphosphatidylcholine B1a cells develop in liver, mature in spleen, and distribute in intestine/colon, mesenteric lymph node (mLN), and body cavity as the outcome of B-1 cell development before B-2 cell development. Throughout life, self-renewing B-1 B1a cells circulate through intestine, mesenteric vessel, and blood. The body cavity-deposited B1a cells also remigrate. In old age, some B1a cells proceed to monoclonal B cell lymphocytosis. When neonatal B-1 B1a cells express an antithymocyte/Thy-1 autoreactivity (ATA) [[BCR]] transgene in the C.B17 mouse background, ATA B cells increase in PBL and strongly develop lymphomas in aging mice that feature splenomegaly and mLN hyperplasia with heightened expression of CD11b, IL-10, and activated Stat3. At the adult stage, ATA B cells were normally present in the mantle zone area, including in intestine. Furthermore, frequent association with mLN hyperplasia suggests the influence by intestinal microenvironment on lymphoma development. When cyclin D1 was overexpressed by the Eμ-cyclin D1 transgene, ATA B cells progressed to further diffused lymphoma in aged mice, including in various lymph nodes with accumulation of IgM IgD [[CD5]] CD23 CD43  cells, resembling aggressive human mantle cell lymphoma. Thus, our findings reveal that early generated B cells, as an outcome of B-1 cell development, can progress to become lymphocytosis, lymphoma, and mantle cell lymphoma-like neoplasia in aged mice.
|mesh-terms=* Aging
* Animals
* Autoantigens
* B-Lymphocytes
* Carcinogenesis
* Cell Differentiation
* Cyclin D1
* Gene Knock-In Techniques
* Lymphoma, Mantle-Cell
* Mice
* Mice, Inbred C57BL
* Mice, Transgenic
* Phosphatidylcholines
* Receptors, Antigen, B-Cell
* STAT3 Transcription Factor

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6036230
}}
{{medline-entry
|title=Age-related changes in mRNA expression of selected surface receptors in lymphocytes of dairy calves.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/29624008
|abstract=The aim of this study was to determine age-related changes in the mRNA expression of four clusters of differentiation (CD: e.g. [[CD5]], CD21, [[CD22]] and CD23) in lymphocytes of calves. Blood samples were collected from 10 Holstein heifers on day 2, 22 and 56 of life and used for lymphocyte isolation. Subsequently, the mRNA was isolated from lymphocytes and the relative expression of [[CD5]], CD21, [[CD22]] and CD23 was investigated using quantitative real-time PCR with [[GAPDH]] as a reference gene. [[CD5]], CD21 and CD23 mRNA expression increased linearly (p ≤ 0.04) with calf age, whereas [[CD22]] mRNA expression did not change in the investigated period (p > 0.05). Age related changes in [[CD5]], CD21 and CD23 mRNA expression suggest their importance in the process of lymphocyte maturation in calves.
|mesh-terms=* Aging
* Animals
* Antigens, CD
* Cattle
* Female
* Gene Expression Regulation, Developmental
* RNA, Messenger
|keywords=* clusters of differentiation
* immune system development
* lymphocyte maturation
* marker
|full-text-url=https://sci-hub.do/10.24425/119039
}}
{{medline-entry
|title=Altered marginal zone and innate-like B cells in aged senescence-accelerated SAMP8 mice with defective IgG1 responses.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28817118
|abstract=Aging has a strong impact on the activity of the immune system, enhancing susceptibility to pathogens and provoking a predominant pre-inflammatory status, whereas dampening responses to vaccines in humans and mice. Here, we demonstrate a loss of marginal zone B lymphocytes (MZ, [[CD19]] [[CD4]]5R CD21 CD23 ) and a decrease of naive B cells ([[CD19]] IgD ), whereas there is an enhancement of a [[CD19]] [[CD4]]5R  innate-like B cell population (B1REL) and the so-called aged B cell compartment (ABC, [[CD4]]5R CD21 CD23 [[CD5]] CD11b ) in aged senescence-accelerated (SAMP8) mice but not in aged senescence-resistant (SAMR1) mice. These changes in aged SAMP8 mice were associated with lower IgG isotype levels, displaying low variable gene usage repertoires of the immunoglobulin heavy chain (V ) diversity, with a diminution on IgG1-memory B cells (CD11b Gr1 CD138 IgM IgD [[CD19]] [[CD38]] IgG1 ), an increase in T follicular helper (T , [[CD4]] [[CXCR5]] PD1 ) cell numbers, and an altered MOMA-1 (metallophilic macrophages) band in primary follicles. LPS-mediated IgG1 responses were impaired in the B1REL and ABC cell compartments, both in vitro and in vivo. These data demonstrate the prominent changes to different B cell populations and in structural follicle organization that occur upon aging in SAMP8 mice. These novel results raise new questions regarding the importance of the cellular distribution in the B cell layers, and their effector functions needed to mount a coordinated and effective humoral response.
|mesh-terms=* Aging
* Animals
* Antigens, CD
* B-Lymphocytes
* Cell Death
* Cell Proliferation
* Gene Expression Regulation, Developmental
* IgG Deficiency
* Immunity, Humoral
* Immunity, Innate
* Immunoglobulin D
* Immunoglobulin G
* Immunoglobulin Heavy Chains
* Immunoglobulin M
* Immunologic Memory
* Lipopolysaccharides
* Mice, Inbred C57BL
* Mice, Transgenic
* Primary Cell Culture
* Signal Transduction
* Spleen
* T-Lymphocytes, Helper-Inducer

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596542
}}
{{medline-entry
|title=Adoptive transfer of autoimmune splenic dendritic cells to lupus-prone mice triggers a B lymphocyte humoral response.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28741259
|abstract=Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by increased autoantibody production that leads to multiple tissue injuries. Dendritic cells (DCs) are important orchestrators of immune responses and key components in fine-tuning the balance between tolerance and immunity. However, their role in autoimmune disorders such as SLE remains uncertain. We analyzed the contribution of DCs in triggering SLE by adoptively transferring splenic DCs from aged autoimmune [NZB×NZW]F1 (BWF1) mice to young healthy BWF1 mice. We observed that the transfer of DCs from autoimmune mice to pre-autoimmune mice induced high autoantibody titers in the serum of recipient mice. Moreover, autoimmune DCs from aged BWF1 mice were crucial for the expansion and differentiation of plasmablasts and [[CD5]]  B cells or B1-like cells in the peripheral blood, and spleen of recipient BWF1 mice, a phenomenon that is observed in autoimmune BWF1 mice. On the other hand, DCs from aged BWF1 mice participated in the expansion and differentiation of DCs and IFN-γ-producing T cells. These results reveal that DCs from autoimmune BWF1 mice exhibit functional and phenotypic characteristics that allow them to trigger B cell hyperactivation, as well as DC and T cell expansion and differentiation, thereby promoting an exacerbated humoral response in lupus-prone mice.
|mesh-terms=* Adoptive Transfer
* Aging
* Animals
* Autoantibodies
* B-Lymphocytes
* Cell Differentiation
* Cell Proliferation
* Cells, Cultured
* Dendritic Cells
* Humans
* Immunity, Humoral
* Interferon-gamma
* Lupus Erythematosus, Systemic
* Lymphocyte Activation
* Mice
* Mice, Inbred NZB
* Spleen
* T-Lymphocytes
|keywords=* Autoimmunity
* B lymphocytes
* Dendritic cells
* Humoral response
* Systemic lupus erythematosus
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5544790
}}
{{medline-entry
|title=Alterations in the Thymic Selection Threshold Skew the Self-Reactivity of the TCR Repertoire in Neonates.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28659353
|abstract=Neonatal and adult T cells differ in their effector functions. Although it is known that cell-intrinsic differences in mature T cells contribute to this phenomenon, the factors involved remain unclear. Given emerging evidence that the binding strength of a TCR for self-peptide presented by MHC (self-pMHC) impacts T cell function, we sought to determine whether altered thymic selection influences the self-reactivity of the TCR repertoire during ontogeny. We found that conventional and regulatory T cell subsets in the thymus of neonates and young mice expressed higher levels of cell surface [[CD5]], a surrogate marker for TCR avidity for self-pMHC, as compared with their adult counterparts, and this difference in self-reactivity was independent of the germline bias of the neonatal TCR repertoire. The increased binding strength of the TCR repertoire for self-pMHC in neonates was not solely due to reported defects in clonal deletion. Rather, our data suggest that thymic selection is altered in young mice such that thymocytes bearing TCRs with low affinity for self-peptide are not efficiently selected into the neonatal repertoire, and stronger TCR signals accompany both conventional and regulatory T cell selection. Importantly, the distinct levels of T cell self-reactivity reflect physiologically relevant differences based on the preferential expansion of T cells from young mice to fill a lymphopenic environment. Therefore, differences in thymic selection in young versus adult mice skew the TCR repertoire, and the relatively higher self-reactivity of the T cell pool may contribute to the distinct immune responses observed in neonates.
|mesh-terms=* Adult
* Aging
* Animals
* Animals, Newborn
* CD5 Antigens
* Cell Differentiation
* Clonal Selection, Antigen-Mediated
* Fetal Blood
* Humans
* Infant, Newborn
* Lymphocyte Activation
* Mice
* Protein Binding
* Receptors, Antigen, T-Cell
* Self Tolerance
* Signal Transduction
* T-Lymphocyte Subsets
* T-Lymphocytes, Regulatory
* Thymocytes
* Thymus Gland

|full-text-url=https://sci-hub.do/10.4049/jimmunol.1602137
}}
{{medline-entry
|title=Developmental expression of B cell molecules in equine lymphoid tissues.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/28063478
|abstract=Identification and classification of B cell subpopulations has been shown to be challenging and inconsistent among different species. Our study tested aspects of ontogeny, phenotype, tissue distribution, and function of equine [[CD5]]  B cells, which represented a greater proportion of B cells early in development and in the peritoneal cavity. [[CD5]]  and [[CD5]]  B cells differentially expressed B cell markers (CD2, CD21, IgM) measured using flow cytometry, but similar mRNA expression of signature genes (DGKA, [[FGL2]], [[PAX5]], [[IGHM]], IL10) measured using quantitative RT-PCR. Sequencing lambda light chain segments revealed that [[CD5]]  B cells generated diverse immunoglobulin repertoires, and more frequently bound to fluorescence-labeled phosphorylcholine. This study shows developmental characteristics and tissue distribution of a newly described subpopulation of B cells in the horse.
|mesh-terms=* Aging
* Animals
* B-Lymphocyte Subsets
* B-Lymphocytes
* CD5 Antigens
* Flow Cytometry
* Horses
* Immunoglobulin Light Chains
* Immunophenotyping
* Lymphoid Tissue
* Phosphorylcholine
|keywords=* B cell
* CD5
* Development
* Equine
* Immunoglobulin repertoire
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5267323
}}
{{medline-entry
|title=[Molecular Mechanisms of Functional Activity Decreasing of the Skin Cells With Its Aging].
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/27530044
|abstract=The article discusses the pool of signaling molecules that regulate the functional activity of the skin cells. Molecules of apoptosis and cells skin aging are p53, p21, p15, Cdk 4/6 and Bcl-2. Inflammation in skin fibroblasts are realized through the cytokines [[TNF]]-α, TGF-β, IL-1, ICAM-1, matrix metalloproteinase MMP-1,2,3,9, transcription factor NF-κB and activator protein AP-1. An important role in the aging of skin cells play neuroimmunoendocrine signaling molecules--melatonin, serotonin, skin fibroblast proliferation marker chromogranin A and CD98hc. Age-related changes in the activity of immune cells of the skin is associated with impaired expression of cluster of differentiation of T-lymphocytes (CD3, [[CD4]], [[CD5]], CD8, CD11) and dendritic cells (CD83⁺). These signaling molecules produced by the fibroblasts of the skin, regulate the activity of immune cells involved in the cascade of reactions associated with inflammatory responses, proliferation, apoptosis and cell regeneration. Based on these data nowadays new highly selective approaches to the diagnosis of the skin and the creation of cosmetic agents for the prevention of aging are developed.
|mesh-terms=* Aging
* Antigens, CD
* Apoptosis
* Cell Proliferation
* Cytokines
* Fibroblasts
* Humans
* Inflammation
* Signal Transduction
* Skin


}}
{{medline-entry
|title=Morphofunctional and signaling molecules overlap of the pineal gland and thymus: role and significance in aging.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26943046
|abstract=Deficits in neuroendocrine-immune system functioning, including alterations in pineal and thymic glands, contribute to aging-associated diseases. This study looks at ageing-associated alterations in pineal and thymic gland functioning evaluating common signaling molecules present in both human and animal pinealocytes and thymocytes: endocrine cell markers (melatonin, serotonin, pCREB, [[AANAT]], CGRP, [[VIP]], chromogranin Ð); cell renovation markers (p53, AIF, Ki67), matrix metalloproteinases (MMP2, MMP9) and lymphocytes markers (CD4, [[CD5]], CD8, CD20). Pineal melatonin is decreased, as is one of the melatonin pathway synthesis enzymes in the thymic gland. A further similarity is the increased MMPs levels evident over age in both glands. Significant differences are evident in cell renovation processes, which deteriorate more quickly in the aged thymus versus the pineal gland. Decreases in the number of pineal B-cells and thymic T-cells were also observed over aging. Collected data indicate that cellular involution of the pineal gland and thymus show many commonalities, but also significant changes in aging-associated proteins. It is proposed that such ageing-associated alterations in these two glands provide novel pharmaceutical targets for the wide array of medical conditions that are more likely to emerge over the course of ageing. 
|mesh-terms=* Aged
* Aged, 80 and over
* Aging
* Biomarkers
* Cell Proliferation
* Cells, Cultured
* Female
* Humans
* Male
* Middle Aged
* Pineal Gland
* Signal Transduction
* Thymus Gland
|keywords=* Gerotarget
* aging
* melatonin
* neuroendocrine-immune
* pineal
* thymus
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4914262
}}
{{medline-entry
|title=Heightened self-reactivity associated with selective survival, but not expansion, of naïve virus-specific CD8  T cells in aged mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26787864
|abstract=In advanced age, decreased CD8( ) cytotoxic T-lymphocyte (CTL) responses to novel pathogens and cancer is paralleled by a decline in the number and function of naïve CTL precursors (CTLp). Although the age-related fall in CD8( ) T-cell numbers is well established, neither the underlying mechanisms nor the extent of variation for different epitope specificities have been defined. Furthermore, naïve CD8( ) T cells expressing high levels of [[CD44]] accumulate with age, but it is unknown whether this accumulation reflects their preferential survival or an age-dependent driver of CD8( ) T-cell proliferation. Here, we track the number and phenotype of four influenza A virus (IAV)-specific CTLp populations in naïve C57BL/6 (B6) mice during aging, and compare T-cell receptor (TCR) clonal diversity for the [[CD44]]hi and [[CD44]]lo subsets of one such population. We show differential onset of decline for several IAV-specific CD8( ) T-cell populations with advanced age that parallel age-associated changes in the B6 immunodominance hierarchy, suggestive of distinct impacts of aging on different epitope-specific populations. Despite finding no evidence of clonal expansions in an aged, epitope-specific TCR repertoire, nonrandom alterations in TCR usage were observed, along with elevated [[CD5]] and CD8 coreceptor expression. Collectively, these data demonstrate that naïve CD8( ) T cells expressing markers of heightened self-recognition are selectively retained, but not clonally expanded, during aging. 
|mesh-terms=* Animals
* CD8-Positive T-Lymphocytes
* Mice
* Mice, Inbred C57BL
|keywords=* CD44  virtual memory
* CD5
* aging
* influenza A virus
* naive CD8  T cells
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4747731
}}
{{medline-entry
|title=[POLYPEPTIDES INFLUENCE ON TISSUE CELL CULTURES REGENERATION OF VARIOUS AGE RATS].
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26390619
|abstract=A comparative study of polypeptides extracted from the tissues of calves: Cortexin (from brain cortex), Epinorm (from pineal gland), Ventvil (from liver), Prostatilen (from prostate), Thymalin (from thymus), Chelohart (from heart), Chondrolux (from cartilage) on the relevant organotypic tissue cultures of young and old rats, in concentration 0,01-100 ng/ml was performed. Polypeptides specifically stimulated "young" and "old" cell cultures growth in concentration 20-50 ng/ml. This effect correlates with increasing of [[PCNA]] and decreasing of p53 expression in brain cortex, pineal gland, liver, prostate, heart, cartilage. Moreover, Thymalin activated [[CD5]], CD20 expression--markers of B-cells differentiation. These data show that polypeptides isolated from different tissues have selective molecular activity on the regeneration of suitable tissues in aging.
|mesh-terms=* Aging
* Animals
* Biomarkers
* Cell Proliferation
* Cells, Cultured
* Male
* Peptides
* Rats
* Rats, Wistar
* Regeneration
* Tissue Culture Techniques


}}
{{medline-entry
|title=Self-recognition drives the preferential accumulation of promiscuous CD4( ) T-cells in aged mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/26173205
|abstract=T-cell recognition of self and foreign peptide antigens presented in major histocompatibility complex molecules (pMHC) is essential for life-long immunity. How the ability of the CD4( ) T-cell compartment to bind self- and foreign-pMHC changes over the lifespan remains a fundamental aspect of T-cell biology that is largely unexplored. We report that, while old mice (18-22 months) contain fewer CD4( ) T-cells compared with adults (8-12 weeks), those that remain have a higher intrinsic affinity for self-pMHC, as measured by [[CD5]] expression. Old mice also have more cells that bind individual or multiple distinct foreign-pMHCs, and the fold increase in pMHC-binding populations is directly related to their [[CD5]] levels. These data demonstrate that the CD4( ) T-cell compartment preferentially accumulates promiscuous constituents with age as a consequence of higher affinity T-cell receptor interactions with self-pMHC. 
|mesh-terms=* Animals
* Autoantigens
* CD4-Positive T-Lymphocytes
* CD5 Antigens
* Mice
* Self Tolerance
|keywords=* CD4
* CD5
* T cell
* aging
* class II MHC
* immunology
* mouse
* repertoire
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4501121
}}
{{medline-entry
|title=Chemotherapy-induced changes and immunosenescence of CD8  T-cells in patients with breast cancer.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/25750301
|abstract=Changes in sub-populations of cytotoxic (CD8 ) T-cells, which are observed in aging and in conditions of chronic immune stimulation, are not well-documented in cancer. Using flow cytometry, CD8  T-cell subsets were analyzed in patients with breast cancer undergoing DNA-damaging chemotherapy and in an older female control group during a six-month longitudinal study, to explore shifts in CD8  T-cells and the effect of DNA-damaging chemotherapy on different T-cell sub-populations. As expected, there was a consistent decrease in absolute numbers of leukocytes, lymphocytes, T-cells and CD8  T-cells during chemotherapy in patients with cancer. Among the T-cells, there was a lower CD8-/CD8  ratio, persisting over the six months, in patients with cancer compared to controls. The proportion of [[CD28]]-[[CD5]]7  cells also remained higher among patients with cancer throughout the sampling duration. The number of [[CD28]] [[CD5]]7- and [[CD28]]-[[CD5]]- cells decreased faster during DNA-damaging chemotherapy than [[CD28]] [[CD5]]7  and [[CD28]]-[[CD5]]7  cells, while only [[CD28]]-[[CD5]]7- cells showed a significant reconstitutive capacity after six months. Immunosenescence appeared to be pronounced in patients with breast cancer, with senescent CD8  T-cells playing a role. The normal condition was not restored after six months of chemotherapy.
|mesh-terms=* Adult
* Aged
* Breast Neoplasms
* CD28 Antigens
* CD57 Antigens
* CD8-Positive T-Lymphocytes
* Cellular Senescence
* DNA Damage
* Female
* Humans
* Middle Aged
|keywords=* CD28
* CD57
* breast cancer
* cellular senescence
* chemotherapy
* immunosenescence

}}
{{medline-entry
|title=Age-related accumulation of T cells with markers of relatively stronger autoreactivity leads to functional erosion of T cells.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/22321827
|abstract=Thymic involution is a prominent characteristic of an aging immune system. When thymic function is reduced/absent, the peripheral T cell pool is subject to the laws of peripheral T cell homeostasis that favor survival/expansion of T cell receptors with relatively higher functional avidity for self-peptide/MHC complexes. Due to difficulties in assessing the TCR avidity in polyclonal population of T cells, it is currently not known whether high avidity T cells preferentially survive in aging individuals, and what impact this might have on the function of the immune system and development of autoimmune diseases. The phenotype of T cells from aged mice (18-24 months) indicating functional TCR avidity (CD3 and [[CD5]] expression) correlates with the level of preserved thymic function. In mice with moderate thymic output (> 30% of peripheral CD62L(hi) T cells), T cells displayed CD3(low)[[CD5]](hi) phenotype characteristic for high functional avidity. In old mice with drastically low numbers of CD62L(hi) T cells reduced [[CD5]] levels were found. After adult thymectomy, T cells of young mice developed CD3(low)[[CD5]](hi) phenotype, followed by a CD3(low)[[CD5]](low) phenotype. Spleens of old mice with the CD3(low)/[[CD5]](hi) T cell phenotype displayed increased levels of IL-10 mRNA, and their T cells could be induced to secrete IL-10 in vitro. In contrast, downmodulation of [[CD5]] was accompanied with reduced IL-10 expression and impaired anti-CD3 induced proliferation. Irrespective of the CD3/[[CD5]] phenotype, reduced severity of experimental allergic myelitis occurred in old mice. In MTB TCRβ transgenic mice that display globally elevated TCR avidity for self peptide/MHC, identical change patterns occurred, only at an accelerated pace. These findings suggest that age-associated dysfunctions of the immune system could in part be due to functional erosion of T cells devised to protect the hosts from the prolonged exposure to T cells with high-avidity for self.
|mesh-terms=* Aging
* Animals
* Biomarkers
* CD3 Complex
* CD5 Antigens
* Encephalomyelitis, Autoimmune, Experimental
* Interleukin-10
* Mice
* Mice, Inbred C57BL
* Mice, Transgenic
* Models, Immunological
* Phenotype
* T-Lymphocytes
* Thymus Gland

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3305419
}}
{{medline-entry
|title=A conserved enhancer element differentially regulates developmental expression of [[CD5]] in B and T cells.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/21076064
|abstract=We previously identified an enhancer element upstream of the mouse cd5 gene that was required in reporter assays for the induction of cd5 promoter activity by [[BCR]] cross-linking. This element is highly conserved in placental mammals. To determine its physiological role, we have now generated mice with a targeted deletion of the enhancer. The result is the loss of [[CD5]] expression in peritoneal and splenic B-1a cells of adult mice and an inability to induce [[CD5]] by cross-linking of the [[BCR]] on splenic B-2 cells. Surprisingly, [[CD5]] expression on B-1a cells of neonatal mice was only minimally compromised. Cd5 enhancer deletion also had only a modest effect on [[CD5]] expression in the T lineage. Thus, this enhancer provides age- and tissue-specific regulation of [[CD5]] expression and is an example of the utilization of different modes of regulation of expression in T and B cells.
|mesh-terms=* Aging
* Animals
* B-Lymphocytes
* CD5 Antigens
* Enhancer Elements, Genetic
* Gene Expression Regulation
* Immunologic Capping
* Mice
* Mice, Inbred BALB C
* Mice, Knockout
* Organ Specificity
* Peritoneal Cavity
* Receptors, Antigen, B-Cell
* Spleen
* T-Lymphocytes

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3855468
}}
{{medline-entry
|title=Expression of [[CD27]] and CD23 on peripheral blood B lymphocytes in humans of different ages.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/19290077
|abstract=Due to the fact that the coexpression of CD23 and [[CD27]] has been reported to occur in B lymphocytic leukaemic clones and that there is debate about CD23 expression on memory B cells, we evaluated the behaviour of naive B cells (CD23-/[[CD27]]-) and memory B cells ([[CD27]] ) in the peripheral blood of a large number of humans of all ages. B cells were also distinguished into B2 ([[CD5]]-) and B1-a cells ([[CD5]] ). The cell surface expression of [[CD19]], [[CD5]], CD23 and [[CD27]] was assessed on peripheral blood lymphocytes from 1,427 subjects of all ages undergoing peripheral blood immunophenotyping for a variety of reasons. The absolute number of B lymphocytes and the percentage of naive cells (CD23-/[[CD27]]-) decreased with age whereas there was an increase in memory cells ([[CD27]] ). A small subset of B cells co-expressing CD23 and [[CD27]] was present in humans of all ages, although the majority of [[CD27]]  cells were CD23-. The percentages and rate of increase with age of B1-a CD23 /[[CD27]]  were slightly higher than those of B2 cell counterparts. On the basis of our data, age-associated changes in surface markers of B cells seem to be finely balanced and probably related to functional changes after antigen encounters, while the whole peripheral blood B-cell compartment undergoes a quantitative regression.
|mesh-terms=* Aging
* Antigens, CD19
* B-Lymphocyte Subsets
* CD5 Antigens
* Female
* Gene Expression
* Humans
* Male
* Receptors, IgE
* Tumor Necrosis Factor Receptor Superfamily, Member 7
|keywords=* B lymphocytes
* B-1a cells
* CD23
* CD27
|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2652233
}}
{{medline-entry
|title=SCART scavenger receptors identify a novel subset of adult gammadelta T cells.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/18641307
|abstract=Although there has been great progress in the characterization of alphabeta T cell differentiation, selection, and function, gammadelta T cells have remained poorly understood. One of the main reasons for this is the lack of gammadelta T cell-specific surface markers other than the TCR chains themselves. In this study we describe two novel surface receptors, SCART1 and SCART2. SCARTs are related to [[CD5]], [[CD6]], and [[CD163]] scavenger receptors but, unlike them, are found primarily on developing and mature gammadelta T cells. Characterization of SCART2 positive immature and peripheral gammadelta T cells suggests that they undergo lineage specification in the thymus and belong to a new IL-17-producing subset with distinct homing capabilities.
|mesh-terms=* Aging
* Amino Acid Sequence
* Animals
* Cell Lineage
* Cell Movement
* Cells
* Cells, Cultured
* Dermis
* Down-Regulation
* Interleukin-17
* Lymph Nodes
* Mice
* Molecular Sequence Data
* Phylogeny
* Receptors, Antigen, T-Cell, gamma-delta
* Receptors, Cell Surface
* Sequence Alignment
* Signal Transduction
* Thymus Gland

|full-text-url=https://sci-hub.do/10.4049/jimmunol.181.3.1710
}}
{{medline-entry
|title=Age-related changes in the occurrence and characteristics of thymic CD4( ) CD25( ) T cells in mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17627771
|abstract=Natural regulatory CD4( ) CD25( ) T cells play an important role in preventing autoimmunity by maintaining self-tolerance. They express CD25 constitutively and are produced in the thymus as a functionally mature T-cell population. Changes in the potential of these cells to regulate the activity of conventional effector lymphocytes may contribute to an increased susceptibility to infection, cancer and age-associated autoimmune diseases. In this study we demonstrated that the thymi of aged mice are populated by a higher percentage of CD4( ) CD25( ) thymocytes than in young animals. The expression of several surface markers (CD69, [[CD5]], [[CD28]], CTLA-4, CD122, FOXP3), usually used to characterize the phenotype of CD4( ) CD25( ) T regulatory cells, was compared between young and aged mice. We also examined the ability of sorted thymus-deriving regulatory T cells of young and aged BALB/c mice to inhibit the proliferation of lymph node lymphocytes activated in vitro. Natural regulatory T cells isolated from the thymi of young mice suppress the proliferation of responder lymph node cells. We demonstrated that thymus-deriving CD4( ) CD25( ) T cells of old mice maintain their potential to suppress the proliferation of activated responder lymphocytes of young mice. However, their potential to inhibit the proliferation of old responder T cells is abrogated. Differences in the occurrence and activity of CD4( ) CD25( ) thymocytes between young and old animals are discussed in relation to the expression of these surface markers.
|mesh-terms=* Aging
* Animals
* Cell Proliferation
* Cells, Cultured
* Female
* Immunophenotyping
* Interleukin-2 Receptor alpha Subunit
* Mice
* Mice, Inbred BALB C
* Self Tolerance
* T-Lymphocyte Subsets
* T-Lymphocytes, Regulatory
* Thymus Gland

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2266020
}}
{{medline-entry
|title=A comprehensive antibody panel for immunohistochemical analysis of formalin-fixed, paraffin-embedded hematopoietic neoplasms of mice: analysis of mouse specific and human antibodies cross-reactive with murine tissue.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17455084
|abstract=Immunohistochemistry is an indispensable tool in human pathology enabling immunophenotypic characterization of tumor cells. Immunohistochemical analyses of mouse models of human hematopoietic neoplasias have become an important aspect for comparison of murine entities with their human counterparts. The aim of this study was to establish a diagnostic antibody panel for analysis of murine lymphomas/leukemias, useful in formalin-fixed/paraffin-embedded tissue. Overall, 48 antibodies (4 rabbit monoclonal, 12 rabbit polyclonal, 2 goat polyclonal, 11 rat, and 19 mouse monoclonal), which were either mouse-specific (14) or cross-reactive with murine tissue (34) were tested for staining quality and diagnostic value in 468 murine hematopoietic neoplasms. Specific staining was achieved with 29 antibodies, of which 18 were human antibodies cross-reactive with murine tissue. Only 23 (B220, BCL-2, BCL-6, CD117, CD138 (2x), CD3 (2x), CD43, CD45, [[CD5]], CD79 alpha cy, cyclin D1, Ki-67 (2x), Mac-3, Mac-2, lysozyme, mast cell tryptase, [[MPO]], Pax-5, TdT, and TER-119) were regarded as valuable for diagnostic evaluation. Immunohistochemistry was also established in an automated immunostainer for high throughput analysis. The antibody panel developed is useful for the classification of murine lymphomas and leukemias analyzed, and a valuable tool for human and veterinary pathologists involved in the diagnostic interpretation of murine models of hematopoietic neoplasias.
|mesh-terms=* Aging
* Animals
* Antibodies
* Cross Reactions
* Female
* Fixatives
* Formaldehyde
* Hematologic Neoplasms
* Humans
* Immunohistochemistry
* Male
* Mice
* Mice, Inbred BALB C
* Mice, Inbred C3H
* Mice, Inbred C57BL
* Mice, Inbred Strains
* Paraffin Embedding

|full-text-url=https://sci-hub.do/10.1080/01926230701230296
}}
{{medline-entry
|title=The dietary supplement ephedrine induces beta-adrenergic mediated exacerbation of systemic lupus erythematosus in NZM391 mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/15864916
|abstract=The dietary supplement and adrenergic receptor agonist ephedrine has been a controversial topic as its safety has been questioned. Beta-adrenergic receptor (beta-[[AR]]) activation causes immunomodulation, which may contribute to promotion of autoimmune pathology. This report investigated the ability of ephedrine to exacerbate processes associated with autoimmune disease in a lupus-prone mouse model. To mimic human supplementation, ephedrine was administered to NZM391 (lupus-prone) and BALB/c (nonlupus prone) mice orally twice a day for three months at a dose of 50 and 100 microg/day. Some ephedrine-treated NZM391 mice also were preadministered the beta-[[AR]] antagonist propranolol to investigate beta-[[AR]] involvement. Mice were bled monthly, and sera were assayed for a variety of lupus manifestations and immunological measurements. In NZM391 males and females, both doses of ephedrine significantly increased lupus manifestations, including IgG production and organ-directed autoantibody titers, and significantly lowered the ratio of IgG2a/IgG1 compared to controls. Ephedrine significantly decreased female lifespan and significantly increased circulating populations of plasma cells (CD38(hi) CD19(lo) cytoplasmic IgG ) and CD40  B1a cells, while preventing an age-related decrease in the B1a cell population expressing a high level of [[CD5]]. While ephedrine induced gender-specific immunomodulation in BALB/c mice, increases in the lupus manifestations of anti-dsDNA titers and serum urea nitrogen were not detected. Preadministration of propranolol decreased lupus manifestations and serum levels of IgG and IgE in ephedrine-treated mice, but did not block the shift towards IgG1 production. These findings indicate that ephedrine via beta-[[AR]] can exacerbate lupus symptoms in NZM391 mice and that blockade of the beta-[[AR]]s on B cells, and not T cells, apparently was of greater importance as the inhibition of lupus symptoms corresponded to an inhibition of immunoglobulin levels, not a change of Th1/Th2 balance.
|mesh-terms=* Adrenergic beta-Agonists
* Adrenergic beta-Antagonists
* Animals
* Anti-Obesity Agents
* Autoantibodies
* B-Lymphocyte Subsets
* Dietary Supplements
* Ephedrine
* Female
* Immunoglobulin G
* Longevity
* Lupus Erythematosus, Systemic
* Male
* Mice
* Mice, Inbred BALB C
* Plasma Cells
* Propranolol
* T-Lymphocyte Subsets

|full-text-url=https://sci-hub.do/10.1191/0961203305lu2078oa
}}
{{medline-entry
|title=Monoclonal [[CD5]]  and [[CD5]]- B-lymphocyte expansions are frequent in the peripheral blood of the elderly.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/14630808
|abstract=The responsiveness and diversity of peripheral B-cell repertoire decreases with age, possibly because of B-cell clonal expansions, as suggested by the incidence of serum monoclonal immunoglobulins and of monoclonal chronic lymphocytic leukemia (CLL)-like B lymphocytes in clinically silent adults. We phenotyped peripheral blood cells from 500 healthy subjects older than 65 years with no history or suspicion of malignancies and no evidence of lymphocytosis. In 19 cases (3.8%) a kappa/lambda ratio of more than 3:1 or less than 1:3 was found: 9 were [[CD5]] , CD19 , CD23 , CD20low, CD79blow, sIglow (classic CLL-like phenotype); 3 were [[CD5]] , CD19 , CD23 , CD20high, CD79blow, sIglow (atypical CLL-like), and 7 were [[CD5]]-, CD19 , CD20high, CD23-, CD79bbright, FMC7 , sIgbright (non-CLL-like). In 2 subjects, 2 phenotypically distinct unrelated clones were concomitantly evident. No cases were CD10 . Polymerase chain reaction (PCR) analysis demonstrated a monoclonal rearrangement of IgH genes in 15 of 19 cases. No bcl-1 or bcl-2 rearrangements were detected. Using a gating strategy based on CD20/[[CD5]]/CD79 expression, 13 additional CLL-like B-cell clones were identified (cumulative frequency of classic CLL-like: 5.5%). Thus, phenotypically heterogeneous monoclonal B-lymphocyte expansions are common among healthy elderly individuals and are not limited to classic CLL-like clones but may have the phenotypic features of different chronic lymphoproliferative disorders, involving also [[CD5]]- B cells.
|mesh-terms=* Aged
* Aged, 80 and over
* Aging
* B-Lymphocytes
* CD5 Antigens
* Clone Cells
* Female
* Gene Rearrangement
* Genes, Immunoglobulin
* Genes, bcl-1
* Genes, bcl-2
* Humans
* Immunoglobulin Light Chains
* Immunophenotyping
* Leukemia, Lymphocytic, Chronic, B-Cell
* Male

|full-text-url=https://sci-hub.do/10.1182/blood-2003-09-3277
}}
{{medline-entry
|title=B cells in the aged: [[CD27]], [[CD5]], and [[CD40]] expression.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/12714244
|abstract=Ageing is characterized by numerous changes in lymphocyte subpopulations. In the present paper we have focused on B cells carrying the surface markers [[CD27]], [[CD5]] and [[CD40]]. [[CD27]] is considered a marker of primed (memory) cells and its engagement promotes the differentiation of memory B cells into plasma cells. [[CD5]] is expressed on B1 cells, which are considered to be responsible for T cell-independent antibody production other than autoantibodies. The [[CD40]] molecule binds [[CD40]]L (CD154) and is necessary for T-dependent antibody responses. Here we show that the absolute number of [[CD5]]  and [[CD40]]  B cells is decreased in the elderly, while [[CD27]]  B lymphocytes only marginally decrease in centenarians. However, there is a decrease of the percentage of [[CD5]]  B cells, an increase of [[CD27]]  B cells, while [[CD40]] does not change significantly. These data, together with the increased number of NK cells during aging, suggest different regulation of antibody production in the elderly which might be another example of immune remodeling with aging, based on interactions between human B and NK cells.
|mesh-terms=* Adult
* Aged
* Aged, 80 and over
* Aging
* B-Lymphocytes
* Biomarkers
* CD40 Antigens
* CD5 Antigens
* Humans
* Lymphocyte Count
* Middle Aged
* Tumor Necrosis Factor Receptor Superfamily, Member 7

|full-text-url=https://sci-hub.do/10.1016/s0047-6374(03)00013-7
}}
{{medline-entry
|title=Impact of aging upon DBA/2J B cells.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/12675267
|abstract=The influence of age on B lymphocyte phenotype and function in DBA/2J mice was examined. The B cells of this strain express the endogenous minor lymphocyte stimulatory (Mls) retroviral superantigen (SAg) Mls-1a permitting assessment of age-related changes in cognate B cell-T cell interaction. Relative to young DBA/2J mice (< 8 months), old mice (> 17 months) had greater numbers of B cells expressing high levels of IgM and low levels of the CD11b and [[CD5]] antigens characteristic of B-1 B cells. As measured by the T cell proliferative response to Mls, the B cells from old DBA/2J mice had reduced ability to present SAg. Upon interaction with Mls-activated T cells, old B cells secreted more IgM while young B cells made more IgG1, IgG3, and IgG2a. DBA/2J BCL functioned poorly as Mls APCs and made considerably less serum Ig. T cells from old mice exhibited a lower response to SAg and were less capable of promoting B cell differentiation. These results indicate that aging influences the cellular collaboration necessary for humoral immunity.
|mesh-terms=* Aging
* Animals
* Antigen Presentation
* B-Lymphocytes
* CD11b Antigen
* CD5 Antigens
* Enzyme-Linked Immunosorbent Assay
* Female
* Flow Cytometry
* Fluorescent Antibody Technique
* Immunity, Cellular
* Immunoglobulin G
* Immunoglobulin M
* Lymphocyte Culture Test, Mixed
* Male
* Mice
* Mice, Inbred DBA
* Minor Lymphocyte Stimulatory Antigens
* Phenotype
* Spleen
* T-Lymphocytes

|full-text-url=https://sci-hub.do/10.1078/0171-2985-00222
}}
{{medline-entry
|title=B-1 B cell subset composition of DBA/2J mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/12182456
|abstract=Studies of B cell subpopulations have focused upon BALB/c mice and related strains. The B cell subset composition of DBA/2J mice, a prototype strain for BALB/c mice, has been investigated less thoroughly. This report provides the results of a study of the B-1 B cells of DBA/2J mice. In contrast to C.B-17 mice, in which B-1 B cells expressed both the [[CD5]] and CD11b antigens, CD11b expression was most characteristic of DBA/2J B-1 B cells. This was particularly evident in the peritoneal cavity where [[CD5]]-CD11b  B cells were the predominant B cell subpopulation. The number of B-1 B cells increased with age in both the spleen and peritoneal cavity. Strain-specific differences in B cell subset composition may be significant when considering B cell lymphomagenesis with aging.
|mesh-terms=* Aging
* Animals
* B-Lymphocyte Subsets
* CD11b Antigen
* CD5 Antigens
* Mice
* Mice, Inbred DBA
* Peritoneal Cavity
* Spleen

|full-text-url=https://sci-hub.do/10.1078/0171-2985-00133
}}
{{medline-entry
|title=The diabetes-prone NZO/Hl strain. II. Pancreatic immunopathology.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/12118086
|abstract=We report the first combined light and electron microscopic analysis of the pancreas during the development of type 2 diabetes in the New Zealand Obese (NZO) mouse. As in most other polygenic rodent models of type 2 diabetes, hyperglycemia associated with beta cell destruction is male sex-limited. Increasing degrees of hyperinsulinemia and transition to diabetes were clearly reflected by the islet volume fraction, by the beta cell granulation state, and by ultrastructural changes, primarily of the endoplasmic reticulum. One of the unusual histopathologic features of NZO mice of both sexes was the presence of B-lymphocyte enriched leukocytic aggregates in the pancreas. Immunocytochemical analysis of the pancreas of 52-week-old diabetic males indicated enrichment for CD19( ) B lymphocytes. Staining of adjacent sections for CD3 and [[CD5]] indicated [[CD5]] coexpression on some of the CD19( ) cells, suggesting the presence of the B1-B subset associated with generation of natural autoantibodies in other autoimmune-prone New Zealand mouse strains. In addition, plasma cells in peri-insular leukocytic infiltrates were identified by electron microscopy. Hence, although autoimmunity has previously proven to be a secondary manifestation of beta cell destruction in most rodent models of type 2 diabetes, the present observations suggest that B lymphocyte function, in association with male gender, may contribute to the development of insulin resistance and chronic hyperglycemia in the NZO model.
|mesh-terms=* Aging
* Animals
* Diabetes Mellitus, Type 1
* Hyperglycemia
* Islets of Langerhans
* Lymphocyte Subsets
* Male
* Mice
* Mice, Mutant Strains

|full-text-url=https://sci-hub.do/10.1097/01.lab.0000018917.69993.ba
}}
{{medline-entry
|title=Absence of [[CD5]] dramatically reduces progression of pulmonary inflammatory lesions in SHP-1 protein-tyrosine phosphatase-deficient 'viable motheaten' mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/11908943
|abstract=Mice homozygous for the viable motheaten (Hcph(me-v)) mutation are deficient in SHP-1 protein-tyrosine phosphatase, resulting in severe systemic autoimmunity and immune dysfunction. A high percentage of B-cells in viable motheaten mice express the cell surface glycoprotein [[CD5]], in contrast to wild type mice that express [[CD5]] on only a small percentage of B-cells. [[CD5]]( ) B-cells have been associated with autoantibody production. To determine the role of [[CD5]] in the development of the inflammatory disease in me(v)/ me(v) mice, we created a stock of [[CD5]](null)me(v)/ me(v) mice. The longevity of [[CD5]](null)me(v)/ me(v) mice was increased 69% in comparison to me(v)/ me(v) mice on a similar (B6;129) background. The increased lifespan was associated with a marked reduction in pulmonary inflammation. Flow cytometry analysis of spleen cells from [[CD5]](null)me(v)/ me(v) mice at 9-12 weeks of age revealed significant decreases in percentages of IgM/B220 double positive B-cells, Mac-1/Gr-1 double positive cells and CD4( ) T-cells compared with me(v)/ me(v) mice. [[CD5]](null)me(v)/ me(v) mice also had significantly lower serum IgM levels in comparison to me(v)/ me(v) mice. Study of [[CD5]](null)me(v)/ me(v) mice may provide further insight into the role of [[CD5]] in cell signaling and may help explain the observed association of [[CD5]]( ) B-cells with autoimmune disease.
|mesh-terms=* Animals
* Autoantibodies
* Blood Cell Count
* Bone Marrow Cells
* CD5 Antigens
* Female
* Immunoglobulins
* Intracellular Signaling Peptides and Proteins
* Longevity
* Macrophages
* Male
* Mice
* Mice, Inbred C57BL
* Mice, Knockout
* Mice, Mutant Strains
* Pneumonia
* Protein Tyrosine Phosphatase, Non-Receptor Type 6
* Protein Tyrosine Phosphatases
* Spleen

|full-text-url=https://sci-hub.do/10.1006/jaut.2001.0570
}}
{{medline-entry
|title=Ontogeny, distribution and function of [[CD38]]-expressing B lymphocytes in mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/11298353
|abstract=Analysis of expression of [[CD38]], CD45R (B220), IgM and IgD on splenic B lymphocytes from mice of different ages demonstrated [[CD38]] on both immature (B220( ), BCR(-)) and mature (B220( ), BCR( )) B lymphocytes. Similarly, [[CD38]] is expressed as early as B220 on the surface of progenitor B cells in the bone marrow. In spite of expressing of [[CD38]] and IgM, neonatal B cells, in contrast to the adult, failed to proliferate to either anti-[[CD38]] or anti-IgM cross-linking when IL-4 was present. They did, however, respond to LPS and anti-[[CD40]], and by 2 weeks of age they began to respond to anti-[[CD38]] and anti-IgM, reaching adult B cell levels by 4 weeks. Although the distribution of [[CD38]] on adult B cells from most different lymphoid compartments was broadly similar, significantly higher levels of [[CD38]] were expressed on peritoneal B lymphocytes. A detailed analysis, using IgM / IgD ratio and staining with anti-[[CD5]] confirmed that B1 lymphocytes were expressing a high level of [[CD38]]. Interestingly, both immature B cells and peritoneal B1 lymphocytes were unresponsive to anti-[[CD38]]. However, they were activated by LPS or anti-[[CD40]].
|mesh-terms=* ADP-ribosyl Cyclase
* ADP-ribosyl Cyclase 1
* Aging
* Animals
* Antibodies
* Antigens, CD
* Antigens, Differentiation
* B-Lymphocytes
* Bone Marrow Cells
* CD40 Antigens
* Cell Differentiation
* Cell Division
* Female
* Flow Cytometry
* Immunoglobulin D
* Immunoglobulin M
* Lipopolysaccharides
* Lymphocyte Activation
* Membrane Glycoproteins
* Mice
* Mice, Inbred BALB C
* Mice, Inbred C3H
* Mice, Inbred C57BL
* NAD  Nucleosidase
* Peritoneal Cavity
* Peyer's Patches
* Receptor Aggregation
* Spleen
* Stem Cells

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270030
}}
{{medline-entry
|title=[[CD5]]-positive B cells in healthy elderly humans are a polyclonal B cell population.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/11069074
|abstract=B cell chronic lymphocytic leukemia (B-CLL) is a disease of the elderly and is characterized by a malignant clone of [[CD5]]  B cells. In old mice, clonal expansions of [[CD5]]  B cells are a common feature, and these animals frequently develop B-CLL. To investigate whether clonal expansion of [[CD5]]  B cells also occurs in elderly humans, predisposing for the development of B-CLL, we analyzed VH gene rearrangements of [[CD5]]  B cells from blood samples of four healthy, 65-82-years-old volunteers as markers of clonality. [[CD5]]  and [[CD5]]-B cells were obtained by cell sorting, CDRIII of rearranged VH genes were amplified by polymerase chain reaction, and fragment length analysis was performed. All samples demonstrated a polyclonal pattern of VH gene length distribution. In addition, VH gene rearrangements were amplified and sequenced from sorted single cells of two of the donors. No clonally related [[CD5]]  or [[CD5]]- B cells were observed. Thus, development of dominant clones of [[CD5]]  peripheral blood B cells is unlikely to be a common trait of elderly individuals.
|mesh-terms=* Aging
* Animals
* B-Lymphocyte Subsets
* CD5 Antigens
* Clone Cells
* Disease Susceptibility
* Gene Rearrangement, B-Lymphocyte, Heavy Chain
* Humans
* Leukemia, Lymphocytic, Chronic, B-Cell
* Mice
* Polymerase Chain Reaction
* Polymorphism, Restriction Fragment Length
* Species Specificity

|full-text-url=https://sci-hub.do/10.1002/1521-4141(200010)30:10<2918::AID-IMMU2918>3.0.CO;2-C
}}
{{medline-entry
|title=Failure to remove autoreactive Vbeta6  T cells in Mls-1 newborn mice attributed to the delayed development of B cells in the thymus.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/10929068
|abstract=Clonal deletion of autoreactive T cells in the thymus is one of the major mechanisms for establishing tolerance to self-antigens, and self-reactive T cells bearing Vbeta6 T-cell receptors are usually deleted before their maturation in Mls-1a mice. However, these T cells develop transiently in the neonatal thymus, and migrate to the periphery. In order to understand the mechanisms which permit these potentially auto-toxic T cells to generate, we investigated in vivo the physiological or functional properties of the elements involved, such as neonatal T cells, antigens and antigen-presenting cells ([[APC]]). Confirming the previous findings that each of these elements per se is already completed in function in neonates, we investigated the possibility of the absence or immaturity of particular [[APC]] with Mls antigens of their own products in the neonatal thymus. In the search for the cellular and histological changes occurring in the newborn thymus, we found that the elimination of Vbeta6  T cells progressed in parallel with the development of thymic B cells. Involvement of B cells in purging the autoreactive T cells from the newborn thymus was shown by prevention of the deletion of Vbeta6  T cells after the removal of B cells by the treatment of neonates with anti-immunoglobulin M antibodies. The restricted and stable expression of [[CD5]] on the thymic B cells, but not on the splenic cells, suggests that these B cells are not postnatal immigrants from the periphery. Finally, it is concluded that the deficiency in the deletion of self-reactive T cells in the thymus of Mls-1a neonates is due to the delayed development of B cells.
|mesh-terms=* Aging
* Animals
* Animals, Newborn
* Autoimmunity
* B-Lymphocytes
* Clonal Deletion
* Immunoglobulin M
* Mice
* Mice, Inbred Strains
* Minor Lymphocyte Stimulatory Antigens
* Receptors, Antigen, T-Cell, alpha-beta
* T-Lymphocyte Subsets
* Thymus Gland

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2327038
}}
{{medline-entry
|title=Significance of cyclin D1 overexpression for the diagnosis of mantle cell lymphoma: a clinicopathologic comparison of cyclin D1-positive MCL and cyclin D1-negative MCL-like B-cell lymphoma.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/10733493
|abstract=Mantle cell lymphoma (MCL) is a distinct clinicopathologic entity of non-Hodgkin's lymphoma, characterized by a monotonous proliferation of small to medium-sized lymphocytes with co-expression of [[CD5]] and CD20, an aggressive and incurable clinical course, and frequent t(11;14)(q13;q32) translocation. We examined 151 cases of lymphoma with MCL morphology from a viewpoint of cyclin D1 overexpression, which is now easily detectable by immunohistochemistry. 128 cases (85%) showed positive nuclear staining for cyclin D1, while the remaining 23 (15%) were negative. Except for cyclin D1 immunohistochemistry, current diagnostic methods, including morphological and phenotypical examinations, could not make this distinction. Although both the cyclin D1-positive and -negative groups were characterized by male predominance, advanced stages of the disease, frequent extranodal involvement, and low CD23 reactivity, the cyclin D1-positive group showed a higher age distribution (P =.04), larger cell size (P =.02), higher mitotic index (P =.01), more frequent gastrointestinal involvement (P =.05), higher international prognostic index score (P =.05), and lower p27(KIP1) expression (P <.0001). Of particular interest is that cyclin D1-positive MCL showed significantly worse survival than cyclin D1-negative lymphoma (5-year survival: 30% versus 86%, P =.0002), which was confirmed by multivariate analysis to be independent of other risk factors. These data suggest that cyclin D1-positive and -negative groups may represent different entities and that the former closely fits the characteristics of classical, typical MCL. We therefore propose that cyclin D1-positivity should be included as one of the standard criteria for MCL, and that innovative therapies for this incurable disease should be explored on the basis of the new criteria.
|mesh-terms=* Adult
* Aged
* Aged, 80 and over
* Aging
* Cell Nucleus
* Cell Size
* Chromosomes, Human, Pair 11
* Chromosomes, Human, Pair 14
* Cyclin D1
* Female
* Humans
* Immunohistochemistry
* Lymphoma, B-Cell
* Lymphoma, Mantle-Cell
* Male
* Middle Aged
* Mitosis
* Prognosis
* Survival Rate
* Translocation, Genetic


}}
{{medline-entry
|title=Nutrition and immunity in the elderly.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/10604204
|abstract=Immune function declines with age, leading to increased infection and cancer rates in aged individuals. In fact, recent progress in the study of immune ageing has introduced the idea that rather than a general decline in the functions of the immune system with age, immune ageing is mainly characterized by a progressive appearance of immune dysregulation throughout life. Changes appear earlier in life for cell-mediated immunity than for humoral immunity. Thus, age-related modifications in cell-mediated immunity, i.e. changes in naive : memory T-cells, mature : immature T-cells, T-helper 1 : T-helper 2 cells are more important in the elderly than changes in humoral immunity, i.e. [[CD5]] : [[CD5]]  cells or length of antibody responses. Such evolution of the immune system has been linked to declining thymus function and to accumulative antigenic influence over the lifespan. In contrast, innate immunity (macrophage functions) is preserved or even increased during the ageing process. This finding shows that the 'primitive' immune system is less affected by the ageing process than the sophisticated specific immune system. The present review focuses on innate and cell-mediated immune changes with ageing. It provides evidence that primary changes (intrinsic modifications in the immune system) and secondary changes (resulting from environmental influences during the lifespan) exert different influences on the immune system. Primary changes, occurring in healthy individuals, seem less important nowadays than they were considered to be previously. For example, interleukin 2 secretion in some very healthy aged individuals is comparable with that in younger adults. Primary immune changes may not explain the increased incidence and severity of infections observed in the elderly population. Secondary immunological changes are far more frequent and are certainly responsible for most of the immune modifications observed in the elderly population. Environmental factors leading to secondary immune dysfunctions include not only antigenic influence, which is a reflection of diseases experienced over the lifespan, but also many other factors such as drug intake, physical activity and diet; factors for which important changes occur in the elderly population. Nutritional factors play a major role in the immune responses of aged individuals and the present review shows that nutritional influences on immune responses are of great consequence in aged individuals, even in the very healthy elderly.
|mesh-terms=* Adult
* Aged
* Aging
* Antibody Formation
* Humans
* Immunity
* Immunity, Cellular
* Nutritional Physiological Phenomena

|full-text-url=https://sci-hub.do/10.1017/s0029665199000907
}}
{{medline-entry
|title=Cellular basis of B cell clonal populations in old mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/10352251
|abstract=Previous studies from this laboratory have shown that >85% of old mice have stable B cell clonal populations detectable by Ig heavy chain complementary-determining region 3 mRNA size analysis and confirmed by sequence analysis. B cells from the same clone are frequently detected in several lymphoid compartments of the same mouse. We now report the phenotype of all ten stable B cell clonal populations detected in five 20-month-old C57BL/6 mice. These clonal B cells appear to develop in the periphery and nine of the ten B cell clonal populations expressed the [[CD5]] cell surface marker. Stable B cell expansions may be dominated by cells at two stages of differentiation. Some B cell populations were detected with DNA as well as RNA and represent large clonal populations of B cells, detectable in several lymphoid compartments. These populations are found predominantly in B cell populations expressing CD45R/B220 and the mRNA coding for the membrane-bound form of the mu Ig heavy chain, which suggests a predominance of B lymphocytes in these populations. In other cases, smaller clonal populations were detected only in splenic RNA samples. These clonal populations were found predominantly among CD45R/B220- B cells and did not express the membrane-bound form of the micro Ig heavy chain. We offer the hypothesis that the B cell clonal populations present in old mice may be precursors of the two types of B cell neoplasms which are dominated by [[CD5]]  B cells (B cell chronic lymphocytic leukemia) or plasma cells (multiple myeloma).
|mesh-terms=* Aging
* Animals
* B-Lymphocyte Subsets
* Bone Marrow Cells
* Cell Lineage
* Cellular Senescence
* Clone Cells
* Female
* Immunoglobulin mu-Chains
* Leukocyte Common Antigens
* Mice
* Mice, Inbred C57BL
* Organ Specificity
* Peritoneal Cavity
* RNA, Messenger
* Receptors, Antigen, B-Cell
* Stem Cells


}}
{{medline-entry
|title=Age-related changes in blood lymphocyte subsets of Chinese children.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9920221
|abstract=Flow cytometric analysis of major lymphocyte populations and their subsets reveals age-related changes in the human cellular immune system. Immunophenotypic markers were evaluated in 136 healthy pediatric subjects divided into groups of newborn infants (cord blood), children aged 1 to 2 years, 2 to 5 years, and 6 to 15 years. The percentage of T cells increased gradually with age and the evolution of the percentage of B and NK cells was found to be variable. The percentage of CD4  cells remains relatively unchanged from infancy to adolescence, but the percentage of CD8  T cells was lowest at birth and reached maximal levels in the one to two year-old period. The percentage of naive T cells declined with time, but the percentage of memory T cells increased with age. Similar trends were seen in T-cell receptor alphabeta- and gammadelta-bearing T cells. The percentage of CD 11b CD8  T cells increased gradually from birth and reached maximal levels from 6 to 15 years old. The expression of the activation markers CD25 and HLA-DR on CD4  T cells increased with age. The percentage of CD16 [[CD5]]6- NK cells declined with age, but the evolution of the percentage of CD 16-[[CD5]]6  NK cells was variable. The fraction of B cells that expressed [[CD5]] was high at birth (72.9%) and was highest in one to two year olds (73.1%), then declined steadily over time. The CD23 antigen was expressed on 41.9% of B cells at birth and 68.6% during the first to second year, then declined steadily with age. These data may serve as a reference range for studies of Chinese pediatric subjects.
|mesh-terms=* Adolescent
* Aging
* Antigens, CD
* B-Lymphocyte Subsets
* Child
* Child, Preschool
* China
* Female
* Flow Cytometry
* Humans
* Immunophenotyping
* Infant
* Infant, Newborn
* Killer Cells, Natural
* Lymphocyte Activation
* Lymphocyte Count
* Lymphocyte Subsets
* Male
* Reference Values
* T-Lymphocyte Subsets

|full-text-url=https://sci-hub.do/10.1111/j.1399-3038.1998.tb00376.x
}}
{{medline-entry
|title=Increased VH 11 and VH Q52 gene use by splenic B cells in old mice associated with oligoclonal expansions of [[CD5]]   B cells.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9701765
|abstract=A significant increase in the utilization of the VH gene families VH11 and Q52 was observed in LPS-stimulated splenic B lymphocytes from aged mice compared to young mice. VH gene usage was assayed by in situ DNA/RNA hybridization using VH family-specific and kappa chain probes. The observed age-dependent differences appear to reflect the preferential use of VH11 and Q52 VH gene use by the [[CD5]]   B lymphocyte subset whose numbers in the spleen increase with age. The increased use of VH11 by splenic cells from old mice is associated with clonal expansions of splenic [[CD5]]   B lymphocytes.
|mesh-terms=* Aging
* Animals
* B-Lymphocyte Subsets
* B-Lymphocytes
* CD5 Antigens
* Cells, Cultured
* Gene Frequency
* Immunoglobulin Heavy Chains
* Mice
* Mice, Inbred C57BL
* Nucleic Acid Hybridization
* Spleen

|full-text-url=https://sci-hub.do/10.1016/s0047-6374(98)00004-9
}}
{{medline-entry
|title=The neonatal development of intraepithelial and lamina propria lymphocytes in the murine small intestine.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9587712
|abstract=During early neonatal life, important changes occur in the gut. The intestine is challenged by both milk and a microbial flora. Later on, at weaning, the diet of mice changes from milk to pelleted food leading to changes in microbial contents. This period seems essential for a complete development of the mucosal immune system. We investigated the development of both intraepithelial (IEL) and lamina propria lymphocytes ([[LPL]]), from day 5, and every 5 days, up to day 30 after birth. IEL and [[LPL]] were isolated from the small intestine and the phenotype was assessed by FACS analyses, using antibodies for detection of T-cell markers CD3, TCR alpha beta, TCR gamma delta, [[CD4]], CD8 alpha, CD8 beta, [[CD5]], CD18, [[CD5]]4, and [[CD4]]9d. Our data show a clear increase in the number of [[LPL]] just before weaning, while the number of IEL increased after day 15. A more mature pattern of membrane antigen expression of both IEL and [[LPL]] was observed at weaning. The adhesion molecules CD18, [[CD5]]4, and [[CD4]]9d, essential for cellular communication of lymphocytes, showed an expression peak at weaning. In conclusion, the mouse mucosal immune system develops during the first 3 weeks of neonatal life leading to the formation of a more mature immune system at weaning.
|mesh-terms=* Aging
* Animals
* Cell Adhesion Molecules
* Epithelium
* Immunity, Mucosal
* Intestine, Small
* Mice
* T-Lymphocyte Subsets

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2275980
}}
{{medline-entry
|title=Spermine induces maturation of the immature intestinal immune system in neonatal mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9285387
|abstract=In mice, immunological adaptation of the gut to microbial and nutritional antigens occurs at weaning in parallel with biochemical and morphological maturation. Because oral administration of spermine to neonatal rats has been shown to induce biochemical and morphological maturation, we investigated whether spermine also affects maturation of the mucosal immune system. Swiss mice 7, 12, and 27 days old were given spermine orally (0.5 mumol/g body weight) during 3 days. Intestinal length was measured, and lactase and sucrase activities were determined. The phenotype of intraepithelial and lamina propria lymphocytes was assessed by FACS analysis using markers for CD3, TCR alpha beta, TCR gamma delta, [[CD4]], CD8 alpha, CD8 beta, [[CD5]], CD18, [[CD5]]4, and [[CD4]]9d. Similar to what occurs during natural development, spermine treatment of neonatal mice increased intestinal length, decreased lactase activity, and increased sucrase activity. The percentage of intraepithelial lymphocytes expressing TCR alpha beta, [[CD4]], [[CD5]], and [[CD5]]4, as well as the levels of expression of these antigens, increased after spermine treatment on day 12, similarly to natural maturation. The increase in expression of CD3, TCR gamma delta, CD18, and [[CD4]]9d did not reach statistical significance. No effect was observed on CD8 expression. The phenotype of lamina propria lymphocytes was not affected. Spermine administration to 7- and 27-day-old mice had no effect on the phenotype of either intraepithelial or lamina propria lymphocytes. Oral spermine administration to neonatal mice induced, in parallel with biochemical maturation, precocious maturation of the murine intestinal immune system and particularly affected differentiation of the intraepithelial lymphocyte population.
|mesh-terms=* Aging
* Animals
* Animals, Newborn
* CD4 Antigens
* CD5 Antigens
* Epithelial Cells
* Immunity, Mucosal
* Intercellular Adhesion Molecule-1
* Intestines
* Lactase
* Lymphocytes
* Mice
* Phenotype
* Receptors, Antigen, T-Cell, alpha-beta
* Spermine
* Sucrase
* beta-Galactosidase

|full-text-url=https://sci-hub.do/10.1097/00005176-199709000-00017
}}
{{medline-entry
|title=Nutrition and immunity in the elderly: modification of immune responses with nutritional treatments.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9250135
|abstract=Nutrition has a strong influence on the immune system of the elderly. Aging induces dysregulation of the immune system, mainly as a result of changes in cell-mediated immunity. Aging is associated with changes to the equilibrium of peripheral T and B lymphocyte subsets, such as decreases in the ratios of mature to immature, naive to memory, T helper 1 subset (TH1) to TH2, and [[CD5]]- to [[CD5]]  cells. As a consequence, cell-mediated immune responses are weaker and neither cell-mediated nor humoral responses are as well adapted to the antigen stimulus. Undernutrition, common in aged populations, also induces lower immune responses, particularly in cell-mediated immunity. Protein-energy malnutrition is associated with decreased lymphocyte proliferation, reduced cytokine release, and lower antibody response to vaccines. Micronutrient deficits, namely of zinc, selenium, and vitamin B-6, all of which are prevalent in aged populations, have the same influence on immune responses. Because aging and malnutrition exert cumulative influences on immune responses, many elderly people have poor cell-mediated immune responses and are therefore at a high risk of infection. Nutritional therapy may improve immune responses of elderly patients with protein-energy malnutrition. Supplementation with high pharmacologic doses of a single nutrient (zinc or vitamin E) may be useful for improving immune responses of self-sufficient elderly people living at home. Therefore, nutritional deficiency must be treated in the elderly to reduce infectious risk and possibly slow the aging process.
|mesh-terms=* Aged
* Aging
* Diet
* Humans
* Immunity
* Minerals
* Nutritional Physiological Phenomena
* Protein-Energy Malnutrition

|full-text-url=https://sci-hub.do/10.1093/ajcn/66.2.478S
}}
{{medline-entry
|title=Genetic factors predisposing to B-CLL and to autoimmune disease in spontaneous murine model.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9209361
|abstract=The frequent occurrence of autoimmune diseases in patients with B cell chronic lymphocytic leukemia (B-CLL) or in their family members suggests the involvement of related predisposing genetic factors in the two distinct disorders. Because the majority of B-CLL is of [[CD5]] B cell type, and because the majority of [[CD5]] B cells produces polyreactive autoantibodies, certain regulatory abnormalities in the proliferation and differentiation of [[CD5]] B cells appear to be involved in B-CLL and autoimmune disease, respectively. In studies using MHC(H-2)-congenic New Zealand mouse strains, NZB(H-2d), NZW(H-2z) and NZB x NZW F1(H-2d/z), we found that while H-2d/z heterozygosity acts as one genetic predisposing element for autoimmune disease, by providing the element for abnormal differentiation of [[CD5]] B cells, the H-2z/z homozygosity serves as one predisposition for B-CLL, by promoting the abnormal proliferation of [[CD5]] B cells. Another non-MHC-linked genes were also involved in the aberrant proliferation of [[CD5]] B cells, as determined by microsatellite DNA analysis. Among these, there was a single dominant NZW locus located on chromosome 6, closely linked to the locus for [[TNF]] receptor p55. Hence our mouse model provides an appropriate tool for studying the relationship between genetic factors predisposing to B-CLL and autoimmune diseases.
|mesh-terms=* Aging
* Animals
* Autoantibodies
* Autoimmune Diseases
* B-Lymphocytes
* CD5 Antigens
* Crosses, Genetic
* Disease Models, Animal
* Flow Cytometry
* Gene Rearrangement
* Genes, Immunoglobulin
* Genes, MHC Class II
* H-2 Antigens
* Heterozygote
* Leukemia, Lymphocytic, Chronic, B-Cell
* Lymphocyte Activation
* Mice
* Mice, Inbred Strains


}}
{{medline-entry
|title=Immunophenotypic analysis of foal bronchoalveolar lavage lymphocytes.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9226838
|abstract=The purpose of this study was to define the normal immunophenotype of equine lymphocytes present within the pulmonary air spaces, and to determine if this changes as foals age from one to ten weeks. Six pairs of mares and foals underwent sequential bronchoalveolar lavage (BAL) between 1 and 10 weeks of age. Data were grouped according to foal age (1, 1-3, 3-6, or 6-10 weeks of age) and were compared to adult control values obtained from the mares. BAL cells were harvested and stained with antibodies to the equine homologues of [[CD5]], [[CD4]], CD8, [[[[CD4]]4]], MHC I, MHC II and to equine IgG. Data, including percent positive staining and mean fluorescence intensity, were acquired on a flow cytometer gated for viable lymphocytes. All foals had significantly fewer [[CD5]]  lymphocytes than mares, with the largest differences in the youngest animals. The percentage of [[CD4]]  lymphocytes increased as the foals aged, approaching adult levels by 3 weeks of age, while the percentage of CD8  lymphocytes increased more slowly and approached adult levels by 10 weeks of age. The [[CD4]]:CD8 ratio changed from 1.26 at one week of age to 0.78 by 10 weeks of age, compared to an adult value of 0.66. Lymphocytes from foals less than 6 weeks of age expressed MHC II and [[[[CD4]]4]] at lower levels than adults. The lymphocytic populations within the airways of foals are significantly different from adult animals. This may account for the susceptibility of foals to certain respiratory infections during the first few months of life.
|mesh-terms=* Aging
* Analysis of Variance
* Animals
* Animals, Newborn
* Bronchoalveolar Lavage Fluid
* CD4 Antigens
* CD4-CD8 Ratio
* CD5 Antigens
* CD8 Antigens
* Cell Survival
* Female
* Histocompatibility Antigens Class I
* Histocompatibility Antigens Class II
* Horses
* Hyaluronan Receptors
* Immunophenotyping
* Lymphocyte Subsets
* Lymphocytes
* Major Histocompatibility Complex

|full-text-url=https://sci-hub.do/10.1016/s0378-1135(97)00092-8
}}
{{medline-entry
|title=IL-12 directly stimulates expression of IL-10 by [[CD5]]  B cells and IL-6 by both [[CD5]]  and [[CD5]]- B cells: possible involvement in age-associated cytokine dysregulation.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9184920
|abstract=Constitutive expression of p35 and p40 IL-12 mRNA was detected in splenic macrophages isolated from aged mice. Macrophages were also implicated as the cell type responsible for the dysregulated IL-6 and tumor necrosis factor (TNF)-alpha commonly observed to be constitutively produced by lymphoid cells from aged donors. A role for IL-12 in the aging process was suggested when it was found that recombinant IL-12 (rIL-12) directly stimulated splenic [[CD5]]  B cells to secrete IL-10, and both [[CD5]]  and [[CD5]]- B cells could be directly induced to produce IL-6 in response to rIL-12. Furthermore, splenocytes from aged animals cultured in the presence of anti-IL-12 antibodies demonstrated a significant reduction in spontaneous IL-6, IL-10 and IFN-gamma production. Based on these observations it was concluded that IL-12 might be responsible for the dysregulated production of IL-10 and IFN-gamma known to occur in aged animals. Treatment of aged animals with low doses of dehydroepiandrosterone sulfate, previously established to be immunocorrective in immunosenescent animals, reduced the age-associated alterations in IL-12 mRNA and protein expression. The mechanisms responsible for the abnormal constitutive expression of inflammatory cytokines by the macrophages of aged animals may play an important afferent role in establishing the immunosenescent phenotype.
|mesh-terms=* Aging
* Animals
* Antibodies, Monoclonal
* B-Lymphocyte Subsets
* CD5 Antigens
* Cells, Cultured
* Cytokines
* Female
* Interleukin-10
* Interleukin-12
* Interleukin-6
* Interphase
* Lymphocyte Activation
* Macrophages
* Mice
* Mice, Inbred C57BL
* RNA, Messenger
* Spleen

|full-text-url=https://sci-hub.do/10.1093/intimm/9.5.745
}}
{{medline-entry
|title=Age-dependent changes in peripheral blood lymphocyte subpopulations in cattle: a longitudinal study.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9016389
|abstract=Immunofluorescence and flow cytometric analyses were used to study the age-dependent changes in the peripheral blood lymphocyte (PBL) subpopulations in cattle. Four healthy Holstein heifer calves (A, B, C and D), 1-2 months of age, were used in this study. Sequential peripheral blood samples were collected once a month for up to 2-2.5 years, and once at approximately 4 years of age. For the first 6 months of age, the calves had similar proportions of CD2 , CD4 , CD8  T lymphocytes, CD20  B lymphocytes and MHC class II  lymphocytes. From 2 months of age up to 2-2.5 years of age, all animals had similar proportions of [[CD5]]  cells; but during the same period, animals A and B had significantly lower proportions of WC1  gamma delta T cells than animals C and D. After 7 months of age, however, the proportions of CD2 , CD4  and CD8  T cells in PBL of animals A and B significantly decreased, whereas the proportions of both CD20  B lymphocytes and MHC class II  lymphocytes significantly increased. In contrast, the proportions of the various PBL subpopulations in animals C and D remained virtually unchanged after 7 months of age. For the first 6 months of age, all the calves showed similar absolute counts of PBL. Thereafter, the absolute counts of PBL in animals A and B significantly increased, but remained virtually unchanged in animals C and D. Throughout the study, from 1-2 months up to 2-2.5 years of age the absolute counts of CD2 , CD4 , CD8  and WC1  gamma delta T cells in PBL of the four animals were not significantly different from each other. Up to 6 months of age, the CD4 / CD8  ratio in all calves was 2.38  /- 0.46, but significantly decreased thereafter to 1.81  /- 0.34. However, there were no significant differences in the CD4 /CD8  ratios among individual animals. The increase in the absolute counts of PBL in animals A and B, after 7 months of age, was due to an increase in the absolute counts of [[CD5]]  cells, CD20  B lymphocytes and MHC class II  lymphocytes. Thus, changes in the percent, but not the absolute counts of T lymphocytes, were due to high percent and absolute counts of B lymphocytes, expressing the [[CD5]] and MHC class II antigens.
|mesh-terms=* Aging
* Animals
* Antigens, CD
* Cattle
* Histocompatibility Antigens Class II
* Leukocytes
* Longitudinal Studies
* Lymphocyte Subsets
* Receptors, Antigen, T-Cell, gamma-delta

|full-text-url=https://sci-hub.do/10.1016/s0145-305x(96)00024-9
}}
{{medline-entry
|title=[[CD72]] ligation regulates defective naive newborn B cell responses.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/9023424
|abstract=The biological basis for reduced Ig production by naive newborn B cells compared to adult peripheral blood B cells is not fully understood. In a Con A   IL-2 T cell-dependent system using "competent" adult T cells, adult B cells produced large amounts of IgM, IgG, and IgA, while cord B cells were restricted to low levels of only IgM production. Cord B cell activation was also diminished. The contribution of specific B-T cell contact-mediated events to the diminished cord B cell response in this system, using mAbs to [[CD40]], [[CD28]], [[CD80]], and [[CD72]], were investigated, as well as regulation of B cell Ig production by cytokines. alpha[[CD72]] ligation increased cord B cell activation and IgM production, but did not affect adult B cells. Blocking alpha[[CD40]] mAb inhibited cord B cell Ig production completely, but only partly inhibited adult B cell Ig production even at high concentration, suggesting a greater sensitivity of cord B cells to disruption of the [[CD40]]-[[CD40]]L interaction. Addition of IL-10 did not increase cord B cell Ig production, while adult B cell Ig production was increased. However, combined addition of IL-10 and alpha[[CD72]] significantly increased cord B cell Ig production over that in the presence of either alpha[[CD72]] or IL-10 alone, but had no effect on adult B cells over that of IL-10 alone. These data suggest that the diminished T cell-dependent response of cord B cells is due to reduced or absent [[CD72]] ligation. [[CD72]] ligation plays an important role in the induction of primary responses by naive B cells. [[CD72]] modulation of naive B cell sensitivity to IL-10 stimulation may have implications in the induction of class switch, which is deficient in newborn B cells. Since all T cells express [[CD5]] constitutively, these data also suggest the existence of another ligand for [[CD72]].
|mesh-terms=* Adult
* Aging
* Antibodies, Monoclonal
* Antibody Formation
* Antigens, CD
* Antigens, Differentiation, B-Lymphocyte
* B-Lymphocytes
* Cell Differentiation
* Cells, Cultured
* Concanavalin A
* Cytokines
* Fetal Blood
* Histocompatibility Antigens Class II
* Humans
* Interleukin-10
* Interleukin-2
* Lymphocyte Activation
* Lymphocyte Cooperation
* Middle Aged
* T-Lymphocytes

|full-text-url=https://sci-hub.do/10.1006/cimm.1996.1033
}}
{{medline-entry
|title=Histological and immunohistological study of the developing and involuting superficial cervical thymus in the koala (Phascolarctos cinereus).
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/8771407
|abstract=The thymuses of 44 koalas, ranging from less than 30 d to more than 14 y of age, were examined histologically and immunohistologically. The thymuses from 17 of these koalas dying acutely through trauma were regarded as not being significantly affected by disease and formed the basis for study of the normal thymus. Most other koalas had chronic illness and, consequently, disease affected (involuted) thymuses. Histologically, thymuses showed obvious corticomedullary differentiation with small Hassall's corpuscles visible in koalas more than 8 mo of age. Most cortical and medullary lymphocytes stained for CD3 and [[CD5]] (T lymphocyte markers) while some cells (predominantly medullary) stained for CD79b (B lymphocytes and plasma cells), IgG (plasma cells) or MHC class II (reticular epithelium, macrophages and possibly lymphocytes). Adults of up to 5-6 y of age which had died through trauma had little evidence of involution and had prominent Hassall's corpuscles and medullary epithelial thymocytes. Thymic eosinopoiesis was an inconsistent finding. In traumatised animals over this age, involution was obvious with fibrous replacement of lobules, loss of Hassall's corpuscles and the development of dilated ducts lined by nonciliated epithelium. However, loss of lymphocytes was gradual and pockets of lymphocytes, centrally located in lobules, were still present in the oldest koala examined. In these involuted thymuses, remaining lymphocytes stained for CD3 and lesser numbers of [[CD5]] and CD79b. Plasma cells were common and often stained both for IgG and MHC class II. Thymuses of chronically diseased koalas showed accelerated involution when age matched with thymuses from traumatised koalas. Chronically ill koalas as young as 18-24 mo showed advanced involution, but the morphological and immunohistological characteristics of involuted thymus from diseased koalas could not be distinguished from those of involuted thymuses derived from traumatised koalas. It was concluded that development of the koala thymus is completed at 8 mo of age and that for normal koalas involution is a gradual process which starts not at but after sexual maturity. Immunohistological characterisation of the thymus was comparable to that reported for a variety of eutherian mammals.
|mesh-terms=* Aging
* Animals
* B-Lymphocytes
* Female
* Immunohistochemistry
* Lymphatic Diseases
* Lymphocytes
* Macrophages
* Male
* Marsupialia
* Plasma Cells
* T-Lymphocytes
* Thymus Gland

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1167838
}}
{{medline-entry
|title=Effect of dietary high doses of vitamin E on the cell size of T and B lymphocyte subsets in young and old CBA mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/8786661
|abstract=Using anti-[[CD5]] and anti-SIgM fluorescent monoclonal antibodies, four subsets of lymphocytes can be distinguished in CBA mice, SIgM  (T2) and SIgM- (T1) T lymphocytes and, [[CD5]]  (B1) and [[CD5]]- (B2) B lymphocytes. L3T4 anti-[[CD4]] and Lyt2 anti-CD8 positivities delineate two major T lymphocyte subsets. The cell size of these subsets has been evaluated by their forward light scatter in flow cytometry after cell fixation. The mean cell size of the different subsets differs, according to subset, age and vitamin E treatment. Globally, there is an age-related increase in size for all subsets. In vitamin-E treated young animals, all subsets are smaller, and the percentages of the biggest B1 and B2 cells decrease. In old mice, the vitamin-E effect is far more variable. B2 cells tend to increase in size but the percentage of the biggest cells diminishes. On the contrary, there is a marked expansion of the large B1 cells. No effect is discernible on [[CD5]]  T lymphocytes, but L3T4 and Lyt2 subpopulations increase in size. This study is a retrospective one and the mechanisms affecting cell size are speculative. Since the lymphocyte cell size was measured after fixation in an hypertonic medium devised for human blood processing, we cannot differentiate a real size modification from a differential volume resistance to experimental conditions. Whatever the case, the changes in cell volume argue for age-related changes in cell membrane permeability and volume homeostasis. For some subsets, cell activation and consequent size increase must also be considered. As far as vitamin E has marked anti-oxidant properties, its effect on cell size provides indirect evidence for a role of free radicals in the observed changes and gives support to the oxidant stress theory of ageing in immune senescence.
|mesh-terms=* Aging
* Animals
* Cell Size
* Diet
* Lymphocytes
* Mice
* Mice, Inbred Strains
* Vitamin E

|full-text-url=https://sci-hub.do/10.1016/0047-6374(95)01666-x
}}
{{medline-entry
|title=Thy1( ) lymphocytes with LAK-like activity are present in rat liver sinusoids.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/8667592
|abstract=Lymphocytes with cytotoxic activity have been identified in sinusoids of rat liver. We investigated the effects of aging on the cytotoxicity of liver sinusoidal lymphocytes in the rat and attempted to identify the cells responsible for cytotoxicity using a Thy1 monoclonal antibody. Natural Killer (NK) activity against YAC1 peaked at the age of 8 weeks, while cytotoxicity against NK-resistant Lymphokine Activated Killer (LAK)-sensitive P815 increased gradually with age. A cold target inhibition assay showed that lymphocytes cytotoxic for P815 and AH109 were also present in the liver sinusoids of aged rats. When these cells were fractionated by the Percoll discontinuous density gradient method, cytotoxic cells were found to comprise large granular lymphocytes (LGLs) rich in low- and middle-density fractions. Cytotoxicity against various targets increased when [[CD5]]( ) cells were removed using [[CD5]]-conjugated beads. Cytotoxicity against P815, AH109 and AH130 was decreased as compared with control lymphocytes when [[CD5]](-) Thy1( ) lymphocytes were removed using [[CD5]], Thy1-conjugated beads. Immunohistologic examination revealed Thy1( ) LGLs with rod-cored vesicles and electron-dense granules in the liver sinusoids. We consider that LAK-like cells with a Thy1 phenotype are present in the liver sinusoids and suggest that they have a broad range of cytotoxicity.
|mesh-terms=* Aging
* Animals
* Cytotoxicity, Immunologic
* Killer Cells, Lymphokine-Activated
* Liver
* Microscopy, Immunoelectron
* Rats
* Rats, Sprague-Dawley
* T-Lymphocytes
* Thy-1 Antigens

|full-text-url=https://sci-hub.do/10.2739/kurumemedj.42.211
}}
{{medline-entry
|title=Human lymphocytes incubated in vitro share multiple characteristics with geriatric-derived lymphocytes: a potential in vitro model for aging?
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/8538241
|abstract=Aging involves a complicated set of parallel reactions that result in multiple cellular and organismic changes and may eventuate in chronic illness. In the immune system, several alterations that correlate with age have been established. In the present study, we report the results of incubating lymphocytes in vitro in whole blood and, employing measures known to be age-dependent, compare these cells 'aged' in vitro with cells from geriatric patients aged in vivo. Cells from blood aged in vivo and incubated in vitro share a number of common characteristics that include decreased growth capacity, shifted growth patterns, increased suppression by adherent cells, decrease in [[CD5]] surface antigen, similar responses to addition of exogenous IL-1, IL-2, PGE2, or indomethacin, and similar production of PGE2. Differences found between in vivo aging and in vitro incubation are IL-2 plasma levels and IL-2 production by activated cells monitored in conditioned minimal medium. Based on these observations, this in vitro system provides a simple method to generate cells that exhibit a very significant subset, but not all, of the characteristics associated with in vivo aging in lymphocytes.
|mesh-terms=* Adult
* Aged
* Aging
* Antigens, Surface
* Cell Division
* Cells, Cultured
* Cellular Senescence
* Cyclooxygenase Inhibitors
* Dinoprostone
* Enzyme-Linked Immunosorbent Assay
* Female
* Humans
* Indomethacin
* Lymphokines
* Male
* Middle Aged
* Models, Biological
* T-Lymphocytes

|full-text-url=https://sci-hub.do/10.1016/0047-6374(95)01596-r
}}
{{medline-entry
|title=Developmental regulation of a murine T-cell-specific tyrosine kinase gene, Tsk.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/8421704
|abstract=Protein-tyrosine kinases have been implicated in signal transduction in T lymphocytes after stimulation of many cell-surface molecules, including the T-cell antigen receptor, [[CD4]], CD8, [[CD2]], [[CD5]], and [[CD2]]8. Yet the identities of many of these tyrosine kinases remain unknown. We have isolated a murine tyrosine kinase gene, called Tsk for T-cell-specific kinase, that appears to be exclusively expressed in T lymphocytes. The Tsk cDNA clone encodes a polypeptide of 70 kDa, which is similar in sequence to both the src and abl families of tyrosine kinases. Sequence comparisons also indicate that Tsk contains one src-homology region 2 domain and one src-homology 3 domain but lacks the negative regulatory tyrosine (src Tyr-527) common to src-family kinases. In addition, Tsk expression is developmentally regulated. Steady-state Tsk mRNA levels are 5- to 10-fold higher in thymocytes than in peripheral T cells and increase in the thymus during mouse development from neonate to adult. Furthermore, Tsk is expressed in day 14 fetal thymus, suggesting a role for Tsk in early T-lymphocyte differentiation.
|mesh-terms=* Aging
* Amino Acid Sequence
* Animals
* Animals, Newborn
* Base Sequence
* Cell Differentiation
* Cloning, Molecular
* Gene Expression Regulation
* Genes, abl
* Genes, src
* Mice
* Molecular Sequence Data
* Molecular Weight
* Polymerase Chain Reaction
* Protein-Tyrosine Kinases
* Signal Transduction
* T-Lymphocytes
* Thymus Gland
* Tissue Distribution

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC45725
}}
{{medline-entry
|title=Immune senescence and adrenal steroids: immune dysregulation and the action of dehydroepiandrosterone (DHEA) in old animals.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/8313929
|abstract=Immune senescence is characterized by dysregulation of the immune system. The disorder occurs during old age and is manifested by an increased production of autoantibodies and a decreased production of antibodies to most foreign antigens. These events seem to reflect an altered ratio of activity between the [[CD5]]  and [[CD5]]- B cell subsets. Likewise, there is dysregulation of cytokine production with an increased production of IL-4, IL-5 and IL-6 associated with a decreased production of IL-2. This appears to reflect an altered ratio of activity between the Th1 and Th2 cell subsets. Dehydroepiandrosterone (DHEA) is one of the three principal adrenal steroids; its serum concentration declines with age. Recent results suggest that in vitro culture of lymphocytes, from aged donors, with DHEA or in vivo treatment of old mice with DHA sulphate results in the augmentation of the antibody response to foreign antigens and a reversal in the dysregulated cytokine production by T cells. Thus, a decline in one of the three principal adrenal steroids is associated with age-associated changes in the immune system. Some of these changes can be reversed by exposure to DHEA.
|mesh-terms=* Aging
* Animals
* Antibody Formation
* Autoantibodies
* B-Lymphocyte Subsets
* Cytokines
* Dehydroepiandrosterone
* Mice

|full-text-url=https://sci-hub.do/10.1007/BF01844199
}}
{{medline-entry
|title=Age-associated changes in binding of human B lymphocytes to a VH3-restricted unconventional bacterial antigen.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/7693819
|abstract=We have recently demonstrated that there is a site on Staphylococcal protein A (SpA) that interacts with B cell Ig receptors in a manner comparable with known T cell superantigens, because this binding specificity is restricted to Fab with VH3 H chains and most VH3 Ig bind SpA. In the present studies, SpA was used as a phenotypic marker for VH3 expression by human lymphoid cells. As expected, this Fab-mediated binding specificity was completely inhibited by certain VH3 antibodies but not by antibodies from other VH families. In multiparameter flow cytometric analyses, this binding activity was demonstrated to be highly prevalent among B cells (14 to 54%), and was more common among IgM-bearing B cells compared with IgG-bearing B cells. In all studies, Fab-mediated binding of SpA was uniformly expressed by a greater proportion of [[CD5]]-positive B cells than [[CD5]]-negative B cells. The proportion of B lymphocytes with this VH3-restricted binding capacity was found to undergo age-associated changes, because a large proportion of the peripheral B cells of neonates (mean  /- SD, 46.0  /- 2.9%) bind this site, but two 10-mo-old subjects and older children had significantly lower binding levels (29.0  /- 3.5%) that were the same as binding levels by adult peripheral B lymphocytes (30.2  /- 3.3%). In immunohistochemical studies, tonsilar B cells that bind this site on SpA were shown to be common in mantle zones and germinal centers of secondary follicles. We speculate that Fab-mediated SpA binding represents a fundamental and primitive binding capacity that is part of the human preimmune repertoire, and we discuss the implications for the observed age-dependent shift in Fab-mediated binding of SpA by peripheral blood B cells.
|mesh-terms=* Adult
* Aging
* Antigens, CD
* B-Lymphocytes
* CD5 Antigens
* Child
* Child, Preschool
* Gene Rearrangement
* Humans
* Immunoglobulin Fab Fragments
* Immunoglobulin G
* Immunoglobulin Heavy Chains
* Immunoglobulin M
* Immunoglobulin Variable Region
* Infant
* Infant, Newborn
* Leukocytes, Mononuclear
* Middle Aged
* Staphylococcal Protein A


}}
{{medline-entry
|title=Age-associated increase of [[CD5]]  B cells in the liver of autoimmune (NZB x NZW) F1 mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/7686612
|abstract=The liver has been demonstrated to be a major site for extrathymic differentiation of T cells. In this study, an identification of [[CD5]]  B cells, which are responsible for the onset of autoimmune disease by virtue of autoantibody production, was performed in autoimmune (NZB x NZW) F1 mice. An age-associated increase of [[CD5]]  B cells was demonstrated in the liver of these mice. Although [[CD5]]  B cells (i.e., [[CD5]] IgM  and [[CD5]] B220 ) constituted a minor population of hepatic mononuclear cells (MNC) (< 5%) when mice were young (8 weeks), a large population of [[CD5]]  B cells (10 to 30% of whole MNC) was identified in the liver of mice aged 25 to 30 weeks after the onset of disease. Such age-dependent increase of [[CD5]]  B cells was not observed in any other strains including NZB, NZW, C3H/He and BALB/c mice. The phenotype of hepatic [[CD5]]  B cells was the same as that of [[CD5]]  B cells in the peritoneal cavity and spleen, showing dull-[[CD5]], bright-IgM and dull-B220. High levels of [[CD5]]  B cells were observed in the peritoneal cavity and liver, but not in the spleen nor in any other lymphoid organs in mice aged 30 weeks. Radioimmunoassay of autoantibodies in the 5-day culture supernatants demonstrated that hepatic MNC were unable to produce any amounts of IgM- and IgG-autoantibodies against double-stranded DNA and single-stranded DNA, despite the increased proportion of [[CD5]]  B cells. On the other hand, peritoneal exudate cells produced only IgM-, but not IgG-, autoantibodies, whereas splenic cells were able to produce both IgM- and IgG-autoantibodies.(ABSTRACT TRUNCATED AT 250 WORDS)
|mesh-terms=* Aging
* Animals
* Antigens, CD
* Autoantibodies
* B-Lymphocytes
* CD5 Antigens
* DNA
* DNA, Single-Stranded
* Female
* Immunoglobulins
* Immunophenotyping
* Liver
* Mice
* Mice, Inbred BALB C
* Mice, Inbred C3H
* Mice, Inbred NZB
* T-Lymphocytes

|full-text-url=https://sci-hub.do/10.1111/j.1348-0421.1993.tb03203.x
}}
{{medline-entry
|title=Effect of age on the expressed B cell repertoire: role of B cell subsets.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/7694639
|abstract=Aged humans and experimental animals are impaired in their responses to most foreign antigens although they produce greater amounts of autoantibodies. We have examined the effect of age on the production of antibodies to a prototypic foreign antigen, sheep erythrocytes (SRBC), and to a prototypic autoantigen, bromelain-treated mouse erythrocytes (BrMRBC), in young and old mice before and after immunization with SRBC. Old mice express more anti-BrMRBC plaque-forming cell (PFC) antibodies before and an even greater number after immunization with SRBC than young mice. Conversely, old mice produce far fewer anti-SRBC PFC than young mice following immunization with SRBC. We hypothesized that the differences in the responses of old mice to BrMRBC and SRBC reflects differences in the activity of [[CD5]]  and [[CD5]]- B cells. To test this hypothesis we immunized young and old mice with foreign antigens reported (and confirmed in our studies) to stimulate [[CD5]]  B cells [TNP-ficoll and phosphorylcholine-keyhole limpet hemocyanin (KLH)] or [[CD5]]- B cells (SRBC and TNP-KLH). We found that the PFC response of old mice to antigens mediated by [[CD5]]  B cells was equal to or greater than that of young mice. In contrast the PFC response of old mice induced by antigens mediated by [[CD5]]- B cells was only 10% that of young mice. Thus it appears that the immune response of old mice is well maintained for antigens which elicit a [[CD5]]  B cell response but not for those which elicit a [[CD5]]- B cell response.(ABSTRACT TRUNCATED AT 250 WORDS)
|mesh-terms=* Aging
* Animals
* Antigens, CD
* B-Lymphocyte Subsets
* B-Lymphocytes
* CD5 Antigens
* Cells, Cultured
* Erythrocytes
* Female
* Ficoll
* Hemocyanins
* Immunoglobulin Heavy Chains
* Mice
* Mice, Inbred BALB C
* Mice, Inbred C57BL
* Mice, Inbred CBA
* Phosphorylcholine
* Spleen
* Trinitrobenzenes

|full-text-url=https://sci-hub.do/10.1093/intimm/5.9.1035
}}
{{medline-entry
|title=Subpopulations of T and B cells in perinatally HIV-infected and noninfected age-matched children compared with those in adults.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/7511082
|abstract=Peripheral blood mononuclear cells were quantified for the subsets of [[CD4]], CD8, and [[CD19]] lymphocytes by using [[CD4]]5RA (2H4), CD29(4B4), [[CD5]]7, [[CD5]], CD10, Leu8, HLA-DR, and TCR gamma delta-1 monoclonal antibodies and dual color immunofluorescence. A comparative analysis of lymphocyte subpopulations was made among 52 HIV-infected and 50 age-matched control children and 30 HIV-seropositive and 27 negative control adults. A significant decrease in the [[CD4]] [[CD4]]5RA  "naive" cells was much more marked in HIV-infected children than in HIV-infected adults. A significant percentage increase in the [[CD4]] CD29  "memory" cells was observed in HIV-infected children but not in infected adults; however, the absolute numbers were usually decreased in all age groups. The mean percentage and absolute numbers of [[CD4]] CD7  and [[CD4]] Leu8  cells were decreased in HIV-infected children, although usually not significantly. The CD3 TCR gamma delta-1  did not show any change in the infected children tested. The mean percentage and absolute number of the CD8 HLA-DR  cells increased significantly in HIV-infected persons of all ages. The CD8 [[CD5]]7  cells were increased in percentage and absolute number in HIV-infected children ages 1-4 and 4-8 years. In the adults, no change was noted in either the percentage or absolute number of [[CD19]] [[CD5]]  B cells, a finding similar to that noted in HIV-infected children above 1 year of age. Although adults showed a significant decrease in both percentage and numbers of [[CD5]]- B cells, an increase was noted in the 7- to 12-month-old HIV-infected children. The [[CD19]] CD10  cells showed a slight but significant decrease in the youngest age group and a significant increase in the older age groups of HIV-infected children. These findings indicate that several lymphocyte subpopulations are altered differentially during HIV infection in children of varying ages and in adults.
|mesh-terms=* Adult
* Aging
* Antigens, CD
* Antigens, CD19
* Antigens, Differentiation, B-Lymphocyte
* B-Lymphocyte Subsets
* CD4-Positive T-Lymphocytes
* CD8 Antigens
* Child
* Child, Preschool
* HIV Infections
* Humans
* Immunologic Memory
* Infant
* Integrin beta1
* Neprilysin
* T-Lymphocyte Subsets

|full-text-url=https://sci-hub.do/10.1006/clin.1994.1047
}}
{{medline-entry
|title=Immunofluorescence analysis of B-1 cell ontogeny in the mouse.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/7514440
|abstract=In order to further understand the developmental aspects of B-1 cells, we characterized the ontogeny of this B cell population in the spleen and peritoneal cavity of BALB/c mice. Although there are B-1 cells in the spleen within the first 1-3 weeks after birth, they do not at any stage represent the majority of splenic B cells. Splenic B-1 cells reach peak levels at approximately 9 days after birth. The mesenteric lining that covers the small intestine of 7-day-old mice contains a population of IgM  B cells, while at the same age, there are few lymphoid cells in the peritoneal cavity. Between 7 and 8 days after birth there is an influx of B cells into the peritoneal cavity. At 8 days, the first detectable peritoneal B cells appear to be of the B-1 type based on expression of IL-5 receptor and [[CD5]]. However, these peritoneal B-1 cells do not express Mac-1. This antigen is not expressed by the majority of peritoneal B-1 cells until 3 weeks. This study indicates that the majority of early splenic B cells are not B-1 cells and it suggests that the mesenteric tissues surrounding the gut contain B lymphocytes which traffic into the peritoneal cavity where they then reside.
|mesh-terms=* Aging
* Animals
* Animals, Newborn
* Antibodies, Monoclonal
* Antigens, CD
* B-Lymphocyte Subsets
* CD5 Antigens
* Fluorescent Antibody Technique
* Immunoglobulin M
* Macrophage-1 Antigen
* Mesentery
* Mice
* Mice, Inbred BALB C
* Peritoneal Cavity
* Peritoneal Lavage
* Receptors, Interleukin
* Receptors, Interleukin-5
* Spleen

|full-text-url=https://sci-hub.do/10.1093/intimm/6.3.355
}}
{{medline-entry
|title=Relationships between non organ-specific autoantibody production and age-related modifications of mononuclear cell phenotype.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/3494129
|abstract=13 autoantibodies were sought in 23-26 elderly people and in 47-118 young controls. We found at least one autoantibody (mainly rheumatoid factor, RF, and anti-nuclear antibodies in 17/23 elderly (i.e., 17%) and in 7/45 young controls (i.e., 16%). Autologous rosette-forming cells and Leu-7 positive cells (Natural Killer Cells?) were higher, and OKT4 and OKT8 positive cells lower in the former than in the latter group. We show that elderly have a high proportion of [[CD5]] positive B cells, compared with young controls, following phorbol myristic acetate activation in vitro. This abnormality might account for the discrepancy in production of RF compared to other autoantibodies.
|mesh-terms=* Adult
* Aged
* Aged, 80 and over
* Aging
* Antibodies, Monoclonal
* Antigens, Surface
* Autoantibodies
* B-Lymphocytes
* Humans
* Lymphocyte Activation
* Lymphocytes
* Middle Aged
* Organ Specificity
* Phenotype
* Rheumatoid Factor
* Rosette Formation
* T-Lymphocytes
* Tetradecanoylphorbol Acetate


}}
{{medline-entry
|title=Distinct surface phenotypes of B cells responsible for spontaneous production of IgM and IgG anti-DNA antibodies in autoimmune-prone NZB x NZW F1 mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/2104180
|abstract=Autoimmune-prone NZB x NZW F1 (B/W F1) mice produce a high titer of anti-DNA antibodies, In vivo and in vitro studies showed that in the early life of these mice, the immunoglobulin isotype of these antibodies almost exclusively belongs to IgM class, however, IgG anti-DNA antibodies begin to develop when the mice are about 5-6 months old and the titer exceeds that of IgM antibodies from age 7 months on. We asked whether or not the B cell population responsible for IgM and IgG antibody production belongs to the same lineage. The surface phenotypes of B cell populations responsible for the spontaneous production of either IgM or IgG anti-DNA antibodies were examined using panning and sorting methods with several monoclonal antibodies to B cells, including [[CD5]] (Ly-1) and Lp-3; the latter defines a unique B cell differentiation antigen. We obtained evidence that surface phenotypes of B cells secreting IgM anti-DNA antibodies belong to [[CD5]]  Lp-3- and those of B cells secreting IgG anti-DNA antibodies which occur only in old B/W F1 mice belong to [[CD5]]- Lp-3  subpopulations. The majority of peritoneal B cells were [[CD5]]  Lp-3  throughout the life span of the mice and anti-DNA antibody production was never evidenced. These findings were discussed in relation to age-associated changes of B cell populations in the spleen of this strain of mice.
|mesh-terms=* Aging
* Animals
* Antibodies, Antinuclear
* Antigens, Differentiation, B-Lymphocyte
* Autoimmune Diseases
* B-Lymphocyte Subsets
* Crosses, Genetic
* Disease Susceptibility
* Genetic Predisposition to Disease
* Immunoglobulin G
* Immunoglobulin M
* Lupus Erythematosus, Systemic
* Mice
* Mice, Inbred NZB
* Mice, Inbred Strains

|full-text-url=https://sci-hub.do/10.3109/08916939008993383
}}
{{medline-entry
|title=Age-related changes in human blood lymphocyte subpopulations.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1735817
|abstract=Flow cytometric analysis of major lymphocyte populations and their subsets reveals age-related changes in the cellular human immune system. Immunophenotypic markers were evaluated in 110 normal pediatric subjects, divided into groups of newborn infants, infants aged 2 days to 11 months, and children aged 1 to 6 years and 7 to 17 years; results were then compared with those obtained from 101 normal adults aged 18 to 70 years. Comparisons among age groups from newborn infants through adults reveal progressive declines in the absolute numbers of leukocytes, total lymphocytes, and T, B, and natural killer (NK) cells. The percentages of T cells within the total lymphocyte population increase with age, in both [[CD4]]  and CD8  subsets. Percentages of B and NK cells are higher in newborn infants than in adults. The expression of the activation markers interleukin-2R and HLA-DR on T cells increases with age, as does the NK-associated expression of [[CD5]]7 on CD8 cells. The proportions of B lymphocytes that coexpress [[CD5]] or CDw78 decrease with age, whereas expression of Leu-8 and CD23 increases. The proportion of [[CD4]] cells bearing the [[CD4]]5RA and Leu-8 markers is consistently lower in adults than in children. These data may serve as a reference range for studies of pediatric subjects.
|mesh-terms=* Adolescent
* Adult
* Aged
* Aging
* Antigens, CD
* Child
* Child, Preschool
* Female
* Fetal Blood
* Humans
* Immunophenotyping
* Infant
* Leukocyte Count
* Lymphocyte Subsets
* Male
* Middle Aged

|full-text-url=https://sci-hub.do/10.1016/s0022-3476(05)80430-5
}}
{{medline-entry
|title=[[CD5]]  B lymphocytes in high-risk islet cell antibody-positive and newly diagnosed IDDM subjects.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1718800
|abstract=Human [[CD5]]  B lymphocytes produce autoantibodies that bind to self- and exogenous antigens. Extremely high percentages of [[CD5]]  B lymphocytes are present in the fetal and newborn periods, whereas they constitute only a minority of B lymphocytes in healthy adults. Increased percentages of circulating [[CD5]]  lymphocytes have previously been demonstrated in several autoimmune diseases, including rheumatoid arthritis, progressive systemic sclerosis, Graves' disease, and Sjögren's syndrome. We measured the percentages of B lymphocytes that expressed the [[CD5]] determinant in 93 control subjects (age range 1 day to 59 yr, mean  /- 22.6  /- 17.7 yr), 17 subjects with newly diagnosed insulin-dependent diabetes mellitus (IDDM; range 5-29 yr, mean  /- SD 13  /- 5.9 yr), 31 high-risk islet cell antibody (ICA)-positive nondiabetic subjects (range 4-45 yr, mean  /- SD 19.8  /- 14.1 yr), and 13 subjects with IDDM of greater than 5 yr duration (range 10-43 yr, mean  /- SD 24.2  /- 9.9 yr). We report that [[CD5]]  B-lymphocyte percentages are strikingly age dependent in healthy control subjects, declining progressively from the newborn period to the middle-age years (r = -0.75, P = 0.0001). In ICA  nondiabetic and recent-onset IDDM subjects less than 29 yr of age, the percentage of circulating [[CD5]]  B lymphocytes fell within the 95% confidence intervals established for control subjects. However, the age-dependent rate of decline in the percentage of [[CD5]]  B lymphocytes within the control range was slower in ICA  and newly diagnosed IDDM subjects than in control subjects.
|mesh-terms=* Adolescent
* Adult
* Aging
* Antigens, CD
* Autoantibodies
* B-Lymphocytes
* CD5 Antigens
* Child
* Child, Preschool
* Diabetes Mellitus, Type 1
* Flow Cytometry
* Fluorescent Antibody Technique
* Humans
* Infant
* Infant, Newborn
* Islets of Langerhans
* Middle Aged
* Regression Analysis

|full-text-url=https://sci-hub.do/10.2337/diab.40.10.1314
}}
{{medline-entry
|title=A developmental switch in B lymphopoiesis.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1722338
|abstract=B and T lymphocytes are generated from hematopoietic stem cells during both fetal and adult life. A critical unresolved issue is whether the differentiation pathways in lymphopoiesis are the same in fetal and adult animals or whether they differ, similar to the hemoglobin switch in erythropoiesis. We report here that a developmental switch occurs in B lymphopoiesis. We isolated "pro-B" cells (i.e., cells that have initiated, but not completed, heavy-chain gene rearrangement) from fetal and adult sources and investigated their B-cell progeny generated both in vitro and in vivo. Most of the cells from fetal liver, but few from adult bone marrow, expressed [[CD5]]. Further, fetal pro-B cells failed to generate cells expressing high levels of IgD in severe combined immunodeficiency mice, whereas adult pro-B cells gave rise to [[CD5]]-B cells bearing IgD at levels comparable to the bulk of cells in the spleen of adult mice. Thus, all committed B progenitors in fetal liver of day 16 gestation mice give rise to phenotypically distinct progeny when compared to cells at a comparable differentiation stage in the bone marrow of adult animals. We conclude that the cohort of B-lineage progenitors in early fetal development is committed to a differentiation pathway distinct from that seen in the adult.
|mesh-terms=* Aging
* Animals
* Antigens, CD
* B-Lymphocytes
* Bone Marrow
* CD5 Antigens
* Embryonic and Fetal Development
* Flow Cytometry
* Gene Rearrangement
* Genes, Immunoglobulin
* Immunoglobulin D
* Liver
* Mice
* Mice, Inbred BALB C
* Phenotype
* Polymerase Chain Reaction

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC53173
}}
{{medline-entry
|title=Biased VH gene expression in murine [[CD5]] B cells results from age-dependent cellular selection.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1716209
|abstract=Flow cytometry-purified, peritoneal and splenic [[CD5]]  and [[CD5]]- B cells from neonatal and adult C57BL/6 mice were studied for expression of VH and Vx gene families in RNA colony blot assays, and for frequencies of clones secreting antibodies to bromelain-treated mouse red blood cells (BrMRBC), single-stranded DNA, trimethyl ammonium and bovine gamma-globulin, by limiting dilution. The results show few overall differences between the two B cell subsets, which both manifest ontogenic D-proximal VH preferences that are lost with age. Biased VH11 expression in [[CD5]] B cells is high in adult peritoneum and spleen but absent in newborns. It only partly correlates with the selection of anti-BrMRBC reactivity, which is considerably higher in peritoneum than in spleen. No particular Vx bias was observed in any of the populations studied with the possible exception of Vx22 in peritoneal [[CD5]]  B cells. We conclude that the antibody repertoire expressed by peritoneal [[CD5]]  B cells of adult mice is not the result of a genetic program, but rather the consequence of local, age-dependent cellular selection mechanisms.
|mesh-terms=* Aging
* Animals
* Antibody Specificity
* Antigens, CD
* Ascitic Fluid
* B-Lymphocytes
* CD5 Antigens
* Flow Cytometry
* Gene Expression
* Immunoblotting
* Immunoglobulin Heavy Chains
* Immunoglobulin Variable Region
* Immunoglobulin kappa-Chains
* Mice
* Mice, Inbred C57BL
* RNA
* Spleen

|full-text-url=https://sci-hub.do/10.1002/eji.1830210908
}}
{{medline-entry
|title=Changing pattern of [[CD5]]  CD20  double positive lymphocytes with ageing and cytotoxic chemotherapy.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1715005
|abstract=In this cross-sectional clinical study, it was found that two subtypes of [[CD5]]  B-lymphocytes existed either with [[CD5]]-high and CD20-low or [[CD5]]-low and CD20-high expression, as determined by dual fluorescence analysis with fluorochrome-labeled monoclonal antibodies on a FACScan flowcytometer. In the normal healthy subjects (n = 20), the CD20 positive cells could be broken down into 3 subsets: [[CD5]](2 ) CD20 , 25.4  /- 3.0% (mean  /- S.E.M.), [[CD5]]  CD20(2 ), 18.4  /- 2.4% and [[CD5]]- CD20(2 ), 56.2  /- 2.7%. Similar values were observed in a group of patients (n = 29) suffering from a wide variety of benign or untreated malignant disorders. The [[CD5]](2 ) CD20  subset was typically related to age (Spearman coefficient of correlation rho = 0.77, P less than 0.001 in healthy subjects and rho = 0.46, P = 0.02 in pathological cases). The [[CD5]]  CD20(2 ) subpopulation was a salient feature of newborns and little infants (n = 6, 75.4  /- 2.4%, P less than 0.01). The [[CD5]]- CD20(2 ) subset was characteristically depressed in patients treated with cytotoxics (n = 21, 41.2  /- 3.6%, P = 0.001). As far as cytotoxic chemotherapy may represent a model of accelerated ageing, it is worth noting that, in patients treated with cytotoxics, the [[CD5]] CD20 pattern was frequently disturbed in a hyperyoung or hyperaged picture. That age and cytotoxics can affect [[CD5]] expression on CD20  lymphocytes, suggests some specific B-dysregulation and should be put together with the known emergence of autoantibodies, paraproteinemias and lympho-plasmocytic tumors with age and chemotherapy.
|mesh-terms=* Adult
* Aged
* Aged, 80 and over
* Aging
* Antigens, CD
* Antigens, CD20
* Antigens, Differentiation, B-Lymphocyte
* Antineoplastic Agents
* CD5 Antigens
* Child
* Child, Preschool
* Female
* Humans
* Infant
* Infant, Newborn
* Lymphocyte Subsets
* Male
* Middle Aged
* Neoplasms

|full-text-url=https://sci-hub.do/10.1016/0047-6374(91)90087-g
}}
{{medline-entry
|title=B-cell differentiation following autologous, conventional, or T-cell depleted bone marrow transplantation: a recapitulation of normal B-cell ontogeny.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1698484
|abstract=The circulating lymphocytes of 88 consecutive patients following autologous, conventional, or T-cell depleted bone marrow transplantation were serially analyzed for B-cell surface antigen expression and function. In the majority of patients, except for those who developed chronic graft-versus-host disease, the number of circulating CD20  B cell normalized by the fourth posttransplant month. The earliest detectable B cells normally expressed HLA-DR, [[CD19]], surface immunoglobulin (slg), CD21, Leu-8, and lacked expression of CD10 (CALLA). In addition, the circulating B cells expressed CD1c, [[CD38]], [[CD5]], and CD23 for the first year following transplant, antigens that are normally expressed on a small percentage of circulating B cells in normal adults, but highly expressed on cord blood B cells. Similar to cord blood B cells, patient B cells isolated during the first year following transplant, proliferated normally to Staphylococcus aureus Cowan strain I (SAC), and produced IgM, but minimal or no IgG when stimulated with pokeweed mitogen and SAC, unlike normal adult B cells that produce both. The similar phenotype and function of posttransplant and cord blood B cells, and their similar rate of decline in patients and normal children adds further evidence to support the hypothesis that B-cell differentiation posttransplant is recapitulating normal B-cell ontogeny.
|mesh-terms=* Adult
* Aging
* Antigens, CD
* Antigens, CD20
* Antigens, Differentiation, B-Lymphocyte
* B-Lymphocytes
* Bone Marrow Transplantation
* Cell Differentiation
* Child
* Child, Preschool
* Graft vs Host Disease
* HLA-DR Antigens
* Humans
* Immunoglobulin G
* Immunoglobulin M
* Immunophenotyping
* Infant, Newborn
* Leukocyte Count
* Lymphocyte Activation
* Staphylococcus aureus
* T-Lymphocytes


}}
{{medline-entry
|title=Characteristics and development of the murine B-1b (Ly-1 B sister) cell population.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1376053
|abstract=In this paper we have outlined the evidence for two distinct branches of the B-1 cell lineage. The data show that phenotypically B-1a and B-1b cells are essentially identical, distinguished only by the presence or absence of the [[CD5]] antigen. Functionally no differences between the two populations have yet been identified. Both produce anti-PtC antibodies, a specificity not observed in conventional B cells. Both produced high levels of IgM as measured in adoptive transfer experiments. Developmentally, B-1a and B-1b cells are indistinguishable with respect to generation from progenitors present in fetal liver and omentum, feedback regulation of new B-1a and B-1b cells from bone marrow, self-replenishment from Ig  cells following adoptive transfer, and the generation of clonal populations. The major difference in the two populations is seen in the development of B-1a and B-1b cells from B220- progenitors in the adult bone marrow. Although B220- B-1a progenitors are rare in adult (greater than 6 weeks) bone marrow, the progenitors for B-1b cells persist well into adulthood. Our understanding of B-1b cell ontogeny is at a stage similar to that of B-1a cells five years ago. We have evidence from transfer experiments that strongly suggests the existence of two distinct progenitors for B-1a and B-1b, but we have yet to physically separate these progenitors as Solvansen et al. have done for B-1 and conventional B cells. Furthermore we must determine whether the B-1b cells that develop from fetal liver and bone marrow are functionally and developmentally equivalent to those that develop from adult bone marrow. As with B-1a cells, the role of B-1b cells in the immune system is unclear. Although we have not yet discerned functional differences between B-1a and B-1b, given the recent identification of [[CD72]] (Lyb-2) as the ligand for [[CD5]], it is tempting to speculate that B-1a cells are more involved in B-B cell interactions such as idiotype-anti-idiotype regulation of the early B-cell repertoire and that B-1b cells are more involved in B-T cell interactions. Whatever their function, it is clear that in trying to understand the role of the B-1 lineage it is important to consider both the B-1a and B-1b lineages.
|mesh-terms=* Aging
* Animals
* Antigens, CD
* B-Lymphocyte Subsets
* CD5 Antigens
* Embryonic and Fetal Development
* Hematopoietic Stem Cells
* Immunoglobulin M
* Immunotherapy, Adoptive
* Mice
* Mice, Inbred Strains
* Phenotype
* Spleen

|full-text-url=https://sci-hub.do/10.1111/j.1749-6632.1992.tb24591.x
}}
{{medline-entry
|title=The ontogeny and functional characteristics of human B-1 ([[CD5]]  B) cells.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1377947
|abstract=We demonstrate that, on average, greater than 90% of B lymphocytes in fetal spleen express [[CD5]] at gestational ages of 17-23 weeks. Similarly, [[CD5]]  B cells (B-1 cells) are the major B cell subset in umbilical cord blood. These findings depend on the optimization of fluorochrome conjugated anti-[[CD5]] reagents for multiparameter fluorescent-activated cell sorter (FACS) analysis. From infancy through childhood the percentage of B-1 cells gradually diminishes in both spleen and peripheral blood. Stable adult levels, 25-35% of the total B cell population, are reached in late adolescence. The decrease in the percentage of B-1 cells in spleen is accompanied by an increase in conventional ([[CD5]]-) B cells, keeping the percentage of total B cells per mononuclear cells relatively constant. In contrast, in peripheral blood, the concentration of both B-1 cells and total B cells decreases, while T cells increase. At the functional level, we show that polyreactive IgM autoantibodies are produced by FACS-sorted [[CD5]]high B cells, but not by [[CD5]]- B cells from adolescent spleen. In contrast, fetal splenic [[CD5]]high and [[CD5]]- B cells appear functionally uniform, both producing IgM autoantibodies that are typical of B-1 cells. The apparent level of [[CD5]]- B cells in fetal spleen, on average 10% of total B cells, may still result from limitations of our reagent. The prominence of B-1 cells in fetal spleen and cord blood, the gradual reduction of B-1 cells with increasing age, and its characteristic repertoire, all suggest a role for this cell type in immunologically immature hosts.
|mesh-terms=* Adolescent
* Adult
* Aging
* Antibody Specificity
* Antigens, CD
* B-Lymphocytes
* CD5 Antigens
* Child
* Child, Preschool
* Fetal Blood
* Fetus
* Flow Cytometry
* Humans
* Immunoglobulin G
* Immunoglobulin M
* Infant
* Infant, Newborn
* Middle Aged

|full-text-url=https://sci-hub.do/10.1093/intimm/4.2.243
}}
{{medline-entry
|title=Flow cytometric analysis of the expression of murine B and T surface markers from birth to adulthood.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1347752
|abstract=The proportion of nucleated splenocytes bearing B-lymphocyte markers B220, surface IgM (sIgM) and sIgD, as well as the T-lymphocyte markers Thy 1.2, [[CD5]], CD8a and [[CD4]] were quantitated by flow cytometric analysis (FACS) throughout postpartum development in the A/J mouse. Full expression of B lymphocyte markers was achieved much sooner than expression of T lymphocyte markers. This was especially true for B220, which was found on 8% of all splenocytes at day 5 and reached adult levels (47-50%) by weaning at day 22. Expression of sIgM and sIgD were 13% and 9%, respectively, of all splenocytes at day 5 with mature levels not expressed until day 35 postpartum (approximately 36% of cells were positive for these markers). T lymphocyte markers, on the other hand, did not reach full expression until sexual maturity. For example, Thy 1.2 expression was 8% on day 5 and did not reach mature levels (28-30%) until day 56. [[CD5]] closely paralleled Thy 1.2 expression rising from only 2% on day 5 to 27% by day 56. Likewise, CD8a and [[CD4]] marker development paralleled one another with CD8a rising from 1% on day 5 to 10% by day 56 and [[CD4]] rising from 5% on day 5 to 19% by day 56. These data demonstrate the variability in the time of appearance and rate of maturation of the various lymphocyte cell surface markers during postpartum development. They also serve as a reference to identify alterations in lymphocyte development created by immunodeficiency diseases.
|mesh-terms=* Aging
* Animals
* Antigens, CD
* Antigens, Surface
* B-Lymphocytes
* Flow Cytometry
* Lymphocytes
* Membrane Glycoproteins
* Membrane Proteins
* Mice
* T-Lymphocytes
* Thy-1 Antigens

|full-text-url=https://sci-hub.do/10.1016/0165-2478(92)90013-e
}}
{{medline-entry
|title=The immunogenetics of immune senescence.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/1284886
|abstract=Immune senescence is characterized by a dysregulation of the immune system. With respect to humoral immunity, aging is associated with an increased level of many autoantibodies and a decreased antibody response to most foreign antigens. This observation reflects a decreased capacity to activate antibody production by [[CD5]]-negative B cells despite a normal or increased capacity to generate antibodies produced by the [[CD5]]-positive B cells. A similar dysregulation of cell-mediated immunity is manifested by an altered balance in cytokine production by T cells from old as compared to young subjects. Thus, the production of interleukin-2 (IL-2), IL-3 and granulocyte-macrophage colony-stimulating factor by T cells from old subjects is decreased although the production of IL-4, IL-5 and IL-6 is undiminished or actually increased.
|mesh-terms=* Aged
* Aging
* Animals
* Antibody Formation
* Antigens, CD
* Autoimmunity
* B-Lymphocyte Subsets
* CD4-Positive T-Lymphocytes
* CD5 Antigens
* Cytokines
* Gene Rearrangement
* Genes, Immunoglobulin
* Humans
* Immunity, Cellular
* Immunocompetence
* Mice
* Receptors, Antigen


}}