CD80
T-lymphocyte activation antigen CD80 precursor (Activation B7-1 antigen) (BB1) (CTLA-4 counter-receptor B7.1) (B7) (CD80 antigen) [CD28LG] [CD28LG1] [LAB7]
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The social, health, and economic challenges of a steadily increasing aging population demand the use of appropriate translational animal models to address questions like healthy aging, vaccination strategies, or potential interventions during the aging process. Due to their genetic proximity to humans, especially nonhuman primates (NHPs) with a relatively short generation period compared to humans, qualify as excellent animal models for these purposes. The use of common marmosets (Callithrix jacchus) in gerontology research steadily increased over the last decades, yet important information about their aging parameters are still missing. We therefore aimed to characterize their aging immune system by comprehensive flow cytometric phenotyping of blood immune cells from juvenile, adult, aging, and geriatric animals. Aged and geriatric animals displayed clear signs of immunosenescence. A decline in CD4/CD8 ratio, increased expression of HLA-DR and PD-1, higher frequencies of CD95 memory cells, alterations in cytokine secretion, and a decline in the proliferative capacity proved T cell senescence in aging marmosets. Also, the B cell compartment was affected by age-related changes: while overall B cell numbers remained stable with advancing age, expression of the activation marker CD80 increased and immunoglobulin M expression decreased. Interestingly, marmoset B cell memory subset distribution rather mirrored the human situation than that of other NHP. CD21 CD27 naïve B cell frequencies decreased while those of CD21 CD27 tissue memory B cells increased with age. Furthermore, frequencies and numbers of NK cells as part of the innate immune system declined with advancing age. Thus, the observed immunological changes in common marmosets over their life span revealed several similarities to age-related changes in humans and encourages further studies to strengthen the common marmoset as a potential aging model.
MeSH Terms
- Aging
- Animals
- CD4-CD8 Ratio
- Callithrix
- Female
- Flow Cytometry
- Immune System
- Longevity
- Male
- Models, Animal
- Sex Factors
Keywords
- aging
- common marmoset
- immune system
- immunosenescence
- innate and adaptive immunity
- sex
The use of [i]Akkermansia muciniphila[/i] as potential therapeutic intervention is receiving increasing attention. Health benefits attributed to this bacterium include an improvement of metabolic disorders and exerting anti-inflammatory effects. The abundance of [i]A. muciniphila[/i] is associated with a healthy gut in early mid- and later life. However, the effects of [i]A. muciniphila[/i] on a decline in intestinal health during the aging process are not investigated yet. We supplemented accelerated aging [i]Ercc1[/i] mice with [i]A. muciniphila[/i] for 10 weeks and investigated histological, transcriptional and immunological aspects of intestinal health. The thickness of the colonic mucus layer increased about 3-fold after long-term [i]A. muciniphila[/i] supplementation and was even significantly thicker compared to mice supplemented with [i]Lactobacillus plantarum[/i] WCFS1. Colonic gene expression profiles pointed towards a decreased expression of genes and pathways related to inflammation and immune function, and suggested a decreased presence of B cells in colon. Total B cell frequencies in spleen and mesenteric lymph nodes were not altered after [i]A. muciniphila[/i] supplementation. Mature and immature B cell frequencies in bone marrow were increased, whereas B cell precursors were unaffected. These findings implicate that B cell migration rather than production was affected by [i]A. muciniphila[/i] supplementation. Gene expression profiles in ileum pointed toward a decrease in metabolic- and immune-related processes and antimicrobial peptide production after [i]A. muciniphila[/i] supplementation. Besides, [i]A. muciniphila[/i] decreased the frequency of activated CD80 CD273 B cells in Peyer's patches. Additionally, the increased numbers of peritoneal resident macrophages and a decrease in Ly6C monocyte frequencies in spleen and mesenteric lymph nodes add evidence for the potentially anti-inflammatory properties of [i]A. muciniphila[/i]. Altogether, we show that supplementation with [i]A. muciniphila[/i] prevented the age-related decline in thickness of the colonic mucus layer and attenuated inflammation and immune-related processes at old age. This study implies that [i]A. muciniphila[/i] supplementation can contribute to a promotion of healthy aging.
Keywords
- Aging
- Akkermansia muciniphila
- Intestinal barrier
- Intestinal immunity
- Mucus layer
Aging is associated with an increased incidence of cancer. One contributing factor could be modulation of immune cells responsible for anti-tumor responses, such as dendritic cells (DCs) and T cells. These immunological changes may also impact the efficacy of cancer immunotherapies in the elderly. The effects of healthy aging on DCs and T cells, and their impact on anti-mesothelioma immune responses, had not been reported. This study examined DCs and T cells in young (2-5 months; equivalent to 16-26 human years) and elderly (20-24 months; equivalent to 60-70 human years) healthy and mesothelioma-bearing C57BL/6J mice. During healthy aging, elderly lymph nodes adopted a regulatory profile, characterized by: (i) increased plasmacytoid DCs, (ii) increased expression of the adenosine-producing enzyme CD73 on CD11c cells, and (iii) increased expression of multiple regulatory markers (including CD73, the adenosine A2B receptor, CTLA-4, PD-1, ICOS, LAG-3, and IL-10) on CD8 and CD4 T cells, compared to lymph nodes from young mice. Although mesotheliomas grew faster in elderly mice, the increased regulatory status observed in healthy elderly lymph node DCs and T cells was not further exacerbated. However, elderly tumor-bearing mice demonstrated reduced MHC-I, MHC-II and CD80 on CD11c cells, and decreased IFN-γ by CD8 and CD4 T cells within tumors, compared to young counterparts, implying loss of function. An agonist CD40 antibody based immunotherapy was less efficient at promoting tumor regression in elderly mice, which may be due to: (i) failure of elderly CD8 T cells to up-regulate perforin, and (ii) increased expression of multiple regulatory markers on CD11c cells and T cells in elderly tumor-draining lymph nodes (including CD73, PD-1, ICOS, LAG-3, and TGF-β). Our findings suggest that checkpoint blockade may improve responses to immunotherapy in elderly hosts with mesothelioma, and warrants further investigation.
Keywords
- aging
- cancer
- dendritic cells
- immunosuppression
- immunotherapy
Macrophage polarization is a candidate biomarker of disease-related inflammatory status, but its modulation during aging has not been investigated. To do this, the M1/M2 profile was assessed by CD80/CD163 gating in classical (CD14 CD16 ), intermediate (CD14 CD16 ), and non-classical (CD14 CD16 ) monocytes from 31 healthy subjects (CTRs) of different ages. Cytofluorimetric analysis showed a significantly different CD80/CD163 distribution in the three subsets, as more than 80% of classical and intermediate monocytes were CD80 CD163 , whereas most non-classical monocytes were CD80 CD163 and CD163 . Non-classical CD163 monocytes were significantly higher whereas classical CD163 and CD80 CD163 monocytes significantly lower in older than younger CTRs (cut-off, 65 years), suggesting different age-related trends for M2 subsets. To establish whether an M1/M2 imbalance could be associated with disease, 21 patients with acute myocardial infarction (AMI) were compared with older CTRs. The AMI patients showed a significantly decreased proportion of CD163 CD80 and an increased proportion of CD163 and CD163 CD80 cells among classical monocytes, opposite trends to those observed in healthy aging. Moreover, a significantly greater proportion of intermediate and non-classical CD80 monocytes suggested a shift to a pro-inflammatory phenotype. Overall, CD163/CD80 cytofluorimetric characterization of circulating monocytes provides additional information about their polarization and could be an innovative tool to monitor aging.
MeSH Terms
- Aged
- Antigens, CD
- Biomarkers
- Female
- Flow Cytometry
- Gene Expression Regulation
- Humans
- Inflammation
- Killer Cells, Natural
- Macrophages
- Male
- Middle Aged
- Monocytes
- Myocardial Infarction
- T-Lymphocytes
Keywords
- M1/M2 monocytes
- NK/NK-T cells
- acute myocardial infarction
- aging
There is evidence that dendritic cells (DCs) undergo age-related changes that modulate their function with their key role being priming antigen-specific effector T cells. This occurs once DCs develop into antigen-presenting cells in response to stimuli/danger signals. However, the effects of aging on DC responses to bacterial lipopolysaccharide (LPS), the pro-inflammatory cytokine interferon (IFN)-γ and CD40 ligand (CD40L) have not yet been systematically evaluated. We examined responses of blood myeloid (m)DC1s, mDC2s, plasmacytoid (p)DCs, and monocyte-derived DCs (MoDCs) from young (21-40 years) and elderly (60-84 years) healthy human volunteers to LPS/IFN-γ or CD40L stimulation. All elderly DC subsets demonstrated comparable up-regulation of co-stimulatory molecules (CD40, CD80 and/or CD86), intracellular pro-inflammatory cytokine levels (IFN-γ, tumour necrosis factor (TNF)-α, IL-6 and/or IL-12), and/or secreted cytokine levels (IFN-α, IFN-γ, TNF-α, and IL-12) to their younger counterparts. Furthermore, elderly-derived LPS/IFN-γ or CD40L-activated MoDCs induced similar or increased levels of CD8 and CD4 T cell proliferation, and similar T cell functional phenotypes, to their younger counterparts. However, elderly LPS/IFN-γ-activated MoDCs were unreliable in their ability to up-regulate chemokine (IL-8 and monocyte chemoattractant protein (MCP)-1) and IL-6 secretion, implying an inability to dependably induce an inflammatory response. A key age-related difference was that, unlike young-derived MoDCs that completely lost their ability to process antigen, elderly-derived MoDCs maintained their antigen processing ability after LPS/IFN-γ maturation, measured using the DQ-ovalbumin assay; this response implies incomplete maturation that may enable elderly DCs to continuously present antigen. These differences may impact on the efficacy of anti-pathogen and anti-tumour immune responses in the elderly.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Antigens, CD1
- B7-2 Antigen
- CD40 Antigens
- CD40 Ligand
- Dendritic Cells
- Female
- Humans
- Lipopolysaccharides
- Male
- Middle Aged
- Transforming Growth Factor beta
- Young Adult
To evaluate the consequences of plasma from individuals with obesity on parameters associated with immunosenescence in unrelated healthy peripheral blood mononuclear cells (PBMC). Freshly isolated PBMC were incubated in media supplemented with 10% of plasma from individuals with obesity or control subjects for the first 4 hours of 24 to 120 hours of culture. Plasma from individuals with obesity modulated the phenotype of healthy PBMC, leading to a higher rate of apoptosis, lower amounts of phospho-γH2AX and -p53, and mitochondrial dysfunction. After 120 hours, there was a higher secretion of inflammatory cytokines IL-1β and IL-8. CD8 T lymphocytes presented decreased expression of CD28, which is associated with the immunosenescent phenotype. CD14 macrophages showed increased expression of CD80 and CD206, suggesting a modulation in the activation of macrophages. These results demonstrate that chronic systemic inflammation observed in obesity induces dysfunctional features in PBMC that are consistent with premature immunosenescence.
MeSH Terms
- Adult
- Apoptosis
- CD8-Positive T-Lymphocytes
- Culture Media
- Female
- Humans
- Immunosenescence
- Inflammation
- Interleukin-1beta
- Interleukin-8
- Leukocytes, Mononuclear
- Macrophages
- Male
- Obesity
- Serum
- Signal Transduction
The purpose of this study was to investigate the effects of melatonin on selected biomarkers of innate and humoral immune response as well as the antioxidant/oxidant status (superoxide dismutase-SOD and reduced glutathione levels (GSH) to understand whether age-related changes would influence the development of acute Trypanosoma cruzi (T. cruzi) infection. Young- (5 weeks) and middle-aged (18 months) Wistar rats were orally treated with melatonin (gavage) (05 mg/kg/day), 9 days after infection. A significant increase in both SOD activity and GSH levels was found in plasma from all middle-aged melatonin-treated animals. Melatonin triggered enhanced expression of major histocompatibility class II (MHC-II) antigens on antigen-presenting cell (APC) and peritoneal macrophages in all treated animals. High levels of CD4 CD28-negative T cells (*P<.05) were detected in middle-aged control animals. Melatonin induced a significant reduction (***P<.001) in CD28-negative in CD4 and CD8 T cells in middle-aged control animals. Contrarily, the same group displayed upregulated CD4 CD28 T and CD8 CD28 T cells. Melatonin also triggered an upregulation of CD80 and CD86 expression in all young-treated groups. Significant percentages of B and spleen dendritic cells in middle-aged infected and treated animals were observed. Our data reveal new features of melatonin action in inhibiting membrane lipid peroxidation, through the reduction in 8-isoprostane, upregulating the antioxidant defenses and triggering an effective balance in the antioxidant/oxidant status during acute infection. The ability of melatonin to counteract the immune alterations induced by aging added further support to its use as a potential therapeutic target not only for T. cruzi infection but also for other immunocompromised states.
MeSH Terms
- Aging
- Animals
- Antioxidants
- CD28 Antigens
- Chagas Disease
- Macrophages, Peritoneal
- Male
- Melatonin
- Oxidative Stress
- Oxidoreductases
- Rats
- Rats, Wistar
Keywords
Trypanosoma cruzi
- antioxidant protection
- immune response
- melatonin
Organ transplantation in older people is increasing, but how aging impacts B-cell responses to organ transplantation is still unknown. Here, we show that the depletion of B cells with anti-CD20 antibodies has disparate effects depending on recipient age. In young murine recipients, anti-CD20 treatment impaired the ability of immune modulation to extend skin allograft survival. In contrast, anti-CD20 treatment extended allograft survival in aged recipients treated with immune modulation. Although regulatory B-cell function and the numbers of marginal and follicular B cells were similar between age groups, a subpopulation of B cells, termed age-associated B cells (ABCs), accumulated upon aging. ABCs isolated from aged mice exhibited upregulation of CD73, CD80, CD106, and TLR2 and an increased capacity to augment T-cell alloimmunity compared to ABCs from young mice. Importantly, ABCs from aged, but not young, mice impaired the ability of immune modulation to enhance allograft survival after adoptive transfer into young transplant recipients. Our study indicates that ABCs impair the immune regulation of allografts. Thus, recipient age needs to be considered when proposing B-cell-depleting immune therapy.
MeSH Terms
- 5'-Nucleotidase
- Adoptive Transfer
- Aging
- Allografts
- Animals
- Antibodies, Monoclonal
- B-Lymphocytes
- B7-1 Antigen
- Graft Rejection
- Graft Survival
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Skin Transplantation
- Toll-Like Receptor 2
- Transplantation, Homologous
- Vascular Cell Adhesion Molecule-1
Keywords
- Aging
- Animal models
- B cells
- Immune regulation
- Transplantation
Mesothelioma is an almost invariably fatal tumor with chemotherapy extending survival by a few months. One immunotherapeutic strategy is to target dendritic cells (DCs), key antigen-presenting cells involved in antigen presentation, to induce antigen-specific T cell responses. However, DC-targeting will only be effective if DCs are fit-for-purpose, and the functional status of DCs in mesothelioma patients was not clear. We found that mesothelioma patients have significantly decreased numbers of circulating myeloid (m)DC1 cells, mDC2 cells and plasmacytoid (p)DCs relative to healthy age and gender-matched controls. Blood monocytes from patients could not differentiate into immature monocyte-derived DCs (MoDCs), indicated by a significantly reduced ability to process antigen and reduced expression of costimulatory (CD40, CD80 and CD86) and MHC (HLA-DR) molecules, relative to controls. Activation of mesothelioma-derived MoDCs with LPS /-IFNγ generated partially mature MoDCs, evident by limited upregulation of the maturation marker, CD83, and the costimulatory markers. Attempts to rescue mesothelioma-derived DC function using CD40Ligand(L) also failed, indicated by maintenance of antigen-processing capacity and limited upregulation of CD40, CD83, CD86 and HLA-DR. These data suggest that mesothelioma patients have significant numerical and functional DC defects and that their reduced capacity to process antigen and reduced expression of costimulatory molecules could induce anergized/tolerized T cells. Nonetheless, survival analyses revealed that individuals with mesothelioma and higher than median levels of mDC1s and/or whose MoDCs matured in response to LPS, IFNγ or CD40L lived longer, implying their selection for DC-targeting therapy could be promising especially if combined with another treatment modality.
Keywords
- Aging
- CD40Ligand
- Mesothelioma
- immunotherapy
- myeloid dendritic cells
- plasmacytoid dendritic cells
- survival outcomes
Although monocytes and macrophages could serve as new therapeutic targets for treatment of Alzheimer's disease (AD) and aging of the human innate immune system, its role in the pathogenesis of neurodegenerative disorders such as AD are only poorly understood. We have addressed this here by determining the number of CD14 monocytes and the frequency of HLA-DR-, CD80-, and CD86-expression in peripheral blood from healthy volunteers aged 20-79 years, and in AD patients at diagnosis and after 12, 30, and 52 weeks of rivastigmine treatment. While the number of CD14 monocytes remained constant, the expression of HLA-DR, CD80, and CD86 by monocytes increased with age. However, no differences were identified by comparing AD patients with age-matched healthy controls or following treatment of AD patients with rivastigmine. These results indicate that changes in the expression of HLA-DR, CD80, and CD86 are caused by immunosenescence rather than by AD pathology or treatment of AD patients with rivastigmine.
MeSH Terms
- Adult
- Aged
- Aging
- Alzheimer Disease
- Analysis of Variance
- Antigens, CD
- B7-1 Antigen
- B7-2 Antigen
- Cholinesterase Inhibitors
- Female
- HLA-DR Antigens
- Humans
- Lipopolysaccharide Receptors
- Male
- Middle Aged
- Monocytes
- Rivastigmine
- Young Adult
Keywords
- Alzheimer’s disease
- CD80
- CD86
- HLA-DR
- monocytes
This study was undertaken considering that, despite the broad use of the unopposed estrogen replacement therapy in elderly women, data on estrogen influence on the functional capacity of dendritic cells (DCs), and consequently immune response are limited. We examined the influence of 17β-estradiol on phenotype, cytokine secretory profile, and allostimulatory and polarizing capacity of splenic (OX62 ) conventional DCs from 26-month-old (aged) Albino Oxford rats matured in vitro in the presence of LPS, a TLR4 agonist, and R848, a TLR7/8 agonist. In the presence of 17β-estradiol, DCs from aged rats exhibited an impaired ability to mature upon stimulation with LPS, as shown by the lower surface density of MHC II and costimulatory CD80 and CD86 molecules. 17β-Estradiol alone enhanced CD40 expression in OX62 DCs without affecting the expression of other costimulatory molecules, thereby confirming that the expression of this molecule is regulated independently from the regulation of other costimulatory molecules. However, although R848 upregulated the expression of MHC II and CD80 and CD40 costimulatory molecules on DCs, 17β-estradiol diminished the effect of this TLR agonist only on MHC II expression. In conjunction, the previous findings suggest that LPS and R848 elicit changes in the expression of costimulatory molecules via triggering differential intracellular signaling pathways. Furthermore, 17β-estradiol diminished the stimulatory influence of both LPS- and R848-matured OX62 DCs on allogeneic CD4 T lymphocyte proliferation in a mixed lymphocyte reaction (MLR). Moreover, as shown in MLR, the exposure to 17β-estradiol during LPS- and R848-induced maturation diminished Th1- and enhanced Th17-driving capacity and reduced Th1-driving capacity of OX62 DCs, respectively. This suggests that LPS and R848 affect not only the surface phenotype, but also functional characteristics of OX62 DCs triggering distinct intracellular signaling pathways. Collectively, the findings indicate that estrogen directly acting on OX62 DCs, may affect CD4 lymphocyte-dependent immune response in aged female rats.
MeSH Terms
- Aging
- Animals
- Antigens, Differentiation
- CD40 Antigens
- Cell Differentiation
- Cell Proliferation
- Cells, Cultured
- Dendritic Cells
- Estradiol
- Estrogen Replacement Therapy
- Female
- Humans
- Imidazoles
- Lipopolysaccharides
- Lymphocyte Activation
- Lymphocyte Culture Test, Mixed
- Rats
- Rats, Inbred Strains
- Spleen
- Th1 Cells
- Th17 Cells
- Toll-Like Receptor 4
- Toll-Like Receptor 7
Keywords
- 17β-Estradiol
- Aging
- Conventional dendritic cells
- Cytokines
- Rat
- Th polarization
Immunological homeostasis in the respiratory tract is thought to require balanced interactions between networks of dendritic cell (DC) subsets in lung microenvironments in order to regulate tolerance or immunity to inhaled antigens and pathogens. Influenza A virus (IAV) poses a serious threat of long-term disruption to this balance through its potent pro-inflammatory activities. In this study, we have used a BALB/c mouse model of A/PR8/34 H1N1 Influenza Type A Virus infection to examine the effects of IAV on respiratory tissue DC subsets during the recovery phase following clearance of the virus. In adult mice, we found differences in the kinetics and activation states of DC residing in the airway mucosa (AMDC) compared to those in the parenchymal lung (PLDC) compartments. A significant depletion in the percentage of AMDC was observed at day 4 post-infection that was associated with a change in steady-state CD11b and CD11b- AMDC subset frequencies and significantly elevated CD40 and CD80 expression and that returned to baseline by day 14 post-infection. In contrast, percentages and total numbers of PLDC were significantly elevated at day 14 and remained so until day 21 post-infection. Accompanying this was a change in CD11b and CD11b- PLDC subset frequencies and significant increase in CD40 and CD80 expression at these time points. Furthermore, mice infected with IAV at 4 weeks of age showed a significant increase in total numbers of PLDC, and increased CD40 expression on both AMDC and PLDC, when analysed as adults 35 days later. These data suggest that the rate of recovery of DC populations following IAV infection differs in the mucosal and parenchymal compartments of the lung and that DC populations can remain disrupted and activated for a prolonged period following viral clearance, into adulthood if infection occurred early in life.
MeSH Terms
- Aging
- Animals
- Antigen-Presenting Cells
- Antigens, CD
- Biomarkers
- Bronchoalveolar Lavage Fluid
- CD11b Antigen
- Cell Compartmentation
- Cell Count
- Cytokines
- Dendritic Cells
- Disease Models, Animal
- Influenza A virus
- Kinetics
- Lung
- Mice, Inbred BALB C
- Mucous Membrane
- Orthomyxoviridae Infections
- Time Factors
The mechanisms of kidney aging are not yet clear. Studies have shown that immunological inflammation is related to kidney aging. Toll-like receptors (TLRs) are one of the receptor types of the body's innate immune system. The function of the TLR system and the mechanisms by which it functions in renal aging remain unclear. In the present study, we, for the first time, systematically investigated the role of the TLR system and the inflammation responses activated by TLRs during kidney aging. We used western blot and immunohistochemistry to systematically analyze the changes in the expression and activation of the endogenous TLR ligands HSP70 and HMGB1, the TLRs (TLR1-TLR11), their downstream signaling pathway molecules MyD88 and Phospho-IRF-3, and the NF-κB signaling pathway molecules Phospho-IKKβ, Phospho-IκBα (NF-κB inhibition factor α), NF-κBp65, and Phospho-NF-κBp65 (activated NF-κB p65) in the kidneys of 3 months old (youth group), 12 months old (middle age group), and 24 months old (elderly group) rats. We used RT-qPCR to detect the mRNA expression changes of the proinflammatory cytokines CCL3, CCL4, CCL5, CD80, TNF-α, and IL-12b in the rat renal tissues of the various age groups. We found that during kidney aging, the HSP70 and HMGB1 expression levels were significantly increased, and the expression levels of TLR1, 2, 3, 4, 5, and 11 and their downstream signaling pathway molecules MyD88 and Phospho-IRF-3 were markedly elevated. Further studies have shown that in the aging kidneys, the expression levels of the NF-κB signaling pathway molecules Phospho-IKKβ, Phospho-IκBα, NF-κBp65, and Phospho-NF-κBp65 were obviously increased, and those of the proinflammatory cytokines CCL3, CCL4, CCL5, CD80, TNF-α, and IL-12b were significantly upregulated. These results showed that the TLR system might play an important role during the kidney aging process maybe by activating the NF-κB signaling pathway and promoting the high expression of inflammation factors.
MeSH Terms
- Aging
- Animals
- Kidney
- Male
- NF-kappa B
- Phosphorylation
- Rats
- Rats, Inbred F344
- Signal Transduction
- Toll-Like Receptors
Dendritic cells (DCs) are critical for the generation of T-cell responses. DC function may be modulated by probiotics, which confer health benefits in immunocompromised individuals, such as the elderly. This study investigated the effects of four probiotics, Bifidobacterium longum bv. infantis CCUG 52486, B. longum SP 07/3, Lactobacillus rhamnosus GG (L.GG) and L. casei Shirota (LcS), on DC function in an allogeneic mixed leucocyte reaction (MLR) model, using DCs and T-cells from young and older donors in different combinations. All four probiotics enhanced expression of CD40, CD80 and CCR7 on both young and older DCs, but enhanced cytokine production (TGF-β, TNF-α) by old DCs only. LcS induced IL-12 and IFNγ production by DC to a greater degree than other strains, while B. longum bv. infantis CCUG 52486 favoured IL-10 production. Stimulation of young T cells in an allogeneic MLR with DC was enhanced by probiotic pretreatment of old DCs, which demonstrated greater activation (CD25) than untreated controls. However, pretreatment of young or old DCs with LPS or probiotics failed to enhance the proliferation of T-cells derived from older donors. In conclusion, this study demonstrates that ageing increases the responsiveness of DCs to probiotics, but this is not sufficient to overcome the impact of immunosenescence in the MLR.
MeSH Terms
- Adult
- Aged
- Aging
- Antigen Presentation
- Antigens, CD
- Bifidobacterium
- Cell Differentiation
- Cell Proliferation
- Cells, Cultured
- Cytokines
- Dendritic Cells
- Humans
- Isoantigens
- Lactobacillus casei
- Lactobacillus rhamnosus
- Lymphocyte Activation
- Lymphocyte Culture Test, Mixed
- Male
- Probiotics
- Receptors, CCR7
- T-Lymphocytes
- Young Adult
Keywords
- Ageing
- Allogeneic mixed leucocyte reaction
- CFSE
- Cytokine
- DCs
- Dendritic cells
- L. casei Shirota
- LcS
- MLR
- PAMPs
- PRPs
- Probiotics
- carboxyfluorescein diacetate succinimidyl ester
- dendritic cells
- mixed leucocyte reaction
- pathogen recognition patterns
- pathogen-associated molecular patterns
Autoimmunity increases with aging indicative of reduced immune tolerance, but the mechanisms involved are poorly defined. In recent years, subsets of B cells with immunoregulatory properties have been identified in murine models of autoimmune disorders, and these cells downregulate immune responses via secretion of IL10. In humans, immature transitional B cells with a CD19( ) CD24(hi) CD38(hi) phenotype have been reported to regulate immune responses via IL10 production. We found the frequency and numbers of CD19( ) CD24(hi) CD38(hi) cells were reduced in the PBMC pool with age. IL10 expression and secretion following activation via either CD40, or Toll-like receptors was also impaired in CD19( ) CD24(hi) CD38(hi) B cells from healthy older donors. When investigating the mechanisms involved, we found that CD19( ) CD24(hi) CD38(hi) B-cell function was compromised by age-related effects on both T cells and B cells: specifically, CD40 ligand expression was lower in CD4 T cells from older donors following CD3 stimulation, and signalling through CD40 was impaired in CD19( ) CD24(hi) CD38(hi) B cells from elders as evidenced by reduced phosphorylation (Y705) and activation of STAT3. However, there was no age-associated change in expression of costimulatory molecules CD80 and CD86 on CD19( ) CD24(hi) CD38(hi) cells, suggesting IL10-dependent immune suppression is impaired, but contact-dependent suppressive capacity is intact with age. Finally, we found a negative correlation between CD19( ) CD24(hi) CD38(hi) B-cell IL10 production and autoantibody (Rheumatoid factor) levels in older adults. We therefore propose that an age-related decline in CD19( ) CD24(hi) CD38(hi) B cell number and function may contribute towards the increased autoimmunity and reduced immune tolerance seen with aging.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Antigens, CD
- Autoimmunity
- B-Lymphocytes
- Cell Differentiation
- Female
- Humans
- Male
- Middle Aged
- Signal Transduction
- Young Adult
Keywords
- B cells
- autoimmunity
- cellular immunology
- inflammation
- rheumatoid factor
The immune system changes with age. In this study we characterized immune changes by performing immunologic screening profiles on ageing individuals. This study was performed at Akdeniz University, in the Faculty of Medicine, Department of Immunology. Healthy volunteers consisted of a younger group (22 donors) and an older group (45 individuals). All subjects had no serious health problems (i.e. chronic heart, lung, liver or immunological diseases) and were taking no prescribed medications. Flow cytometry analysis was used to evaluate CD3, CD4, CD8, CD16, CD19, CD28, CD40, CD45, CD56, CD80, CD86, CTLA-4 and ELISA for IL-1 beta, IL-2, IL-6, IL-10, IFN-gamma, TNF-alpha expression In addition, NK activity and induced cytokine expression (by bioassay and ELISA, respectively) were evaluated. No statistical differences were observed between the two groups in expression of CD3, CD8, CD19, CD80, CD86, CD16, CD 56, or CD28. A higher frequency of expression of CD4, CTLA-4, CD40, and CD45 was seen in older subjects by comparison with younger subjects. Cytokine profiles expressed by stimulated monocytes and lymphocytes from the two groups showed no difference in IL-1 beta, IL-2, IL-6, IL-10, TNF-alpha, and IFN-gamma production levels. We found increased expression levels of CD40 and CD45 levels in healthy older (age: 59.42 /- 5.89) versus younger individuals (age: 30.32 /- 2.29). CTLA-4 expression levels were also higher in older subjects, with no difference in CD28 expression levels between younger/older individuals.
MeSH Terms
- Adult
- Age Factors
- Aging
- Biomarkers
- CD40 Antigens
- CTLA-4 Antigen
- Cytokines
- Female
- Flow Cytometry
- Humans
- Immunity, Humoral
- Leukocyte Common Antigens
- Lymphocytes
- Male
- Middle Aged
- Monocytes
The expression of monocyte cell-surface receptors represents one index of immune dysfunction, which is common with aging. Although mouse models of aging are prevalent, monocyte subset assessment is rare. Our purpose was to compare cell receptor expression on classic (CD115 /Gr-1 high) and non-classic (CD115 /Gr-1 low) monocytes from 80- or 20-week-old CD-1 mice. Three-colour flow cytometry was used to determine the concentration of monocyte subsets and their respective cell-surface expression of TLR2, TLR4, CD80, CD86, MHC II and CD54. These receptors were selected because they have been previously associated with altered monocyte function. Data were analysed with independent t-tests; significance was set at P less than 0.05. Old mice had a greater concentration of both classic (258%, P=0.003) and non-classic (70%, P=0.026) monocytes. The classic : non-classic monocyte ratio doubled in old as compared with that in young mice (P=0.006), indicating a pro-inflammatory shift. TLR4 ( 27%, P=0.001) and CD80 ( 37%, P=0.004) were decreased on classic monocytes from old as compared with those from young mice. TLR2 ( 24%, P=0.002) and MHCII ( 21%, P=0.026) were altered on non-classic monocytes from old as compared with those from young mice. The increased classic : non-classic monocyte ratio combined with changes in the cell-surface receptor expression on both monocyte subsets is indicative of immune dysfunction, which may increase age-associated disease risk.
MeSH Terms
- Aging
- Animals
- Flow Cytometry
- Mice
- Monocytes
- Receptor, Macrophage Colony-Stimulating Factor
- Receptors, Cell Surface
- Toll-Like Receptor 2
- Toll-Like Receptor 4
Aging has profound effects on the immune system, including thymic involution, reduced diversity of the T cell receptor repertoire, reduced effector T cell and B cell function and chronic increase of proinflammatory cytokine production by innate immune cells. The precise effects of aging on conventional dendritic cells (cDC), the main antigen presenting cells of the immune system, however, are not well understood. We found that in aged mice the number of cDC in the spleen and lymph nodes remained stable, whereas the number of cDC in the lungs increased with age. Whereas cDC in mice showed similar cycling kinetics in all organs tested, cDC reconstitution by aged bone marrow precursors was relatively higher than that of their young counterparts. With the exception of CD86, young and aged cDC did not differ in their expression of co-stimulatory molecules at steady state. Most toll-like receptor (TLR) ligands induced comparable upregulation of co-stimulatory molecules CD40, CD86 and B7H1 on young and aged cDC, whereas TLR2 and TLR5 stimulation resulted in reduced upregulation of CD80 and CD86 on aged cDC in vitro. In vivo, influenza infection-induced upregulation of CD86, but not other co-stimulatory molecules, was lower in aged DC. Young and aged DC were equally capable of direct and cross presentation of antigens in vitro. Transcriptome analysis did not reveal any significant difference between young and aged cDC. These data show that unlike T and B cells, the maintenance of cDC throughout the life of a healthy animal is relatively robust during the aging process.
MeSH Terms
- Aging
- Animals
- Antigen Presentation
- B7-2 Antigen
- B7-H1 Antigen
- Bone Marrow Cells
- CD40 Antigens
- Cell Count
- Dendritic Cells
- Female
- Flow Cytometry
- Immunophenotyping
- Influenza A virus
- Lipopeptides
- Lipopolysaccharides
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Oligonucleotide Array Sequence Analysis
- Orthomyxoviridae Infections
- Spleen
- Toll-Like Receptors
- Transcriptome
- Up-Regulation
Dendritic cells (DC) are specialized antigen-presenting cells, responsible for peripheral immune responses. Recently, resident brain dendritic cells (bDC) were identified and functionally characterized in the young adult Itgax (CD11c) EYFP transgenic mouse brain. In the present study, we describe changes in number, phenotype, and source of bDC in the aging mouse brain. Immunohistochemistry and fluorescent activated cell sorting (FACS) analysis revealed an age-related increase in bDC with a concomitant rise in the expression of immune activation markers MHCII, CD80, and CD86. Quantification of immunolabeled bDC in the cortex, corpus callosum, and cerebellum of the aged brain revealed a 2- to 5-fold increase. In contrast, either no change or a decrease in bDC was noted in regions of adult neurogenesis. Chimeras (wild type host/EYFP bone marrow) suggest that the increase of EYFP cells in the aging brain is in part due to an accumulation of peripherally derived cells. Collectively, the numerical and phenotypic changes in bDC indicate these cells may serve as an important immune component in the functional and anatomic alterations associated with aging.
MeSH Terms
- Age Factors
- Aging
- Analysis of Variance
- Animals
- B7-1 Antigen
- B7-2 Antigen
- Bacterial Proteins
- Brain
- CD11c Antigen
- Calcium-Binding Proteins
- Cell Count
- Dendritic Cells
- Flow Cytometry
- Histocompatibility Antigens Class II
- Humans
- Luminescent Proteins
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Microfilament Proteins
- Radiation Chimera
The T cell branch of the immune system has been extensively studied in the elderly and it is known that the elderly have impaired immune function, mainly due to the chronic antigenic load that ultimately causes shrinkage of the T cell repertoire and filling of the immunologic space with memory T cells. In the present paper, we describe the IgD(-)CD27(-) double-negative B cell population which (as we have recently described) is higher in the elderly. Most of these cells were IgG( ). Evaluation of the telomere length and expression of the ABCB1 transporter and anti-apoptotic molecule, Bcl2, shows that they have the markers of memory B cells. We also show that these cells do not act as antigen presenting cells, as indicated by the low levels of CD80 and DR, nor do they express significant levels of the CD40 molecule necessary to interact with T lymphocytes through the ligand, CD154. Hence, we hypothesize that these expanded cells are late memory or exhausted cells that have down-modulated the expression of CD27 and filled the immunologic space in the elderly. These cells might be the age-related manifestation of time-enduring stimulation or dysregulation of the immune system.
MeSH Terms
- ATP Binding Cassette Transporter, Subfamily B
- ATP Binding Cassette Transporter, Subfamily B, Member 1
- Adult
- Age Factors
- Aged
- Aged, 80 and over
- Aging
- Antigens, CD19
- B-Lymphocyte Subsets
- B7-1 Antigen
- CD40 Antigens
- Cells, Cultured
- Flow Cytometry
- HLA-DR Antigens
- Humans
- Immunoglobulin D
- Immunologic Memory
- Ki-67 Antigen
- Middle Aged
- Proto-Oncogene Proteins c-bcl-2
- Telomere
- Tumor Necrosis Factor Receptor Superfamily, Member 7
- Young Adult
Toll-like receptors (TLRs) recognize a limited number of conserved elements in pathogens and, by activating antigen-presenting cells such as dendritic cells and monocytes and macrophages, play a crucial role in the immune response to infection and vaccination. Most data on TLR function in the context of human aging focus on responses to lipopolysaccharide, an integral component of gram-negative bacteria, which signals through TLR4. However, such studies have not led to a consensus conclusion and are limited by differences in epidemiological and laboratory methods. A recent comprehensive evaluation of TLR function in monocytes from older adults was conducted using a multivariable mixed statistical model to account for covariates. It was found that cytokine production after TLR1/2 engagement, which is essential for the recognition of triacylated lipopeptides found in a variety of bacteria, is substantially lower in monocytes from older adults. The upregulation of costimulatory proteins such as CD80, essential for optimal activation of T cells, on monocytes from older adults was less for all TLR ligands tested than for cells from young individuals, and the extent of CD80 upregulation predicted subsequent antibody response to influenza immunization. These and other consequences of aging on human TLR function may impair activation of the immune response and contribute to poorer vaccine responses and greater morbidity and mortality from infectious diseases in older adults. Such age-associated alterations have particular relevance in view of the interest in TLR agonists as therapeutic agents not only for infections, but also for allergic, autoimmune, and malignant disease.
MeSH Terms
- Aged
- Aged, 80 and over
- Aging
- Animals
- Disease Susceptibility
- Humans
- Immunity, Innate
- Infections
- Middle Aged
- T-Lymphocytes
- Toll-Like Receptors
Polyclonal B cell activation is a hallmark of the immune dysregulation in New Zealand Black (NZB) mice. We have previously shown that the splenic B cell activation is associated with increased CD80 expression. Here we show that abnormal expansions of CD80-expressing GC, CD5( ), marginal zone (MZ) precursor and MZ B cells produce this increase. To investigate the role of BCR engagement in the generation and activation of these populations, a non-self-reactive Ig Tg was introduced onto the NZB background. NZB Ig-Tg mice lacked Tg CD5( ) and peanut agglutinin( ) B cells, confirming the role of endogenous Ag in their selection. Although the increased proportion of MZ B cells was retained in NZB Ig-Tg mice, CD80 expression on these cells was reduced as compared to non-Tg NZB mice, suggesting a role for BCR engagement with endogenous Ag in their activation. Examination of CD40L-knockout NZB mice showed no difference in the abnormal activation or selection of the B cell populations, with the exception of GC cells, as compared to wild-type NZB mice. Thus, polyclonal B cell activation in NZB mice does not require CD40 engagement, but results, in part, from dysregulated BCR-specific mechanisms.
MeSH Terms
- Aging
- Animals
- B-Lymphocytes
- CD40 Ligand
- Cell Differentiation
- Cell Proliferation
- Lymphocyte Activation
- Lymphocyte Count
- Mice
- Mice, Inbred NZB
- Receptors, Antigen, B-Cell
Innate immunity, including Toll-like receptor (TLR)-mediated expression of the B7 costimulatory molecules CD80 and CD86, is critical for vaccine immunity. We examined whether CD80 and CD86 expression vary with aging and predict response to the trivalent inactivated influenza vaccine. One hundred sixty-two subjects between 21 and 30 years of age (the young group) or > or =65 years of age (the older group) enrolled before vaccination. We determined TLR-induced monocyte CD80/CD86 expression by flow cytometry and vaccine antibody responses by hemagglutination inhibition. The mean increase in TLR-induced CD80( ) monocytes was reduced in older, compared with young, adults by 68% (P=.0002), and each decile increase of CD80( ) cells was associated with an 8.5% increase in mean number of vaccine strains with a > or =4-fold titer increase (P=.01) and a 3.8% increase in mean number of strains with a postvaccine titer > or =1 : 64 (P=.037). Each decile decrease of CD86( ) cells was associated with an 11% increase in the mean number of strains with a 4-fold increase (P=.002) and a 3.9% increase in the mean number of strains with a postvaccine titer > or =1 : 64 (P=.07). CD80 and CD86 expression on activated monocytes is highly associated with influenza vaccine response. This approach prospectively identifies adults unlikely to respond to immunization who may benefit from alternative vaccines or antiviral prophylaxis during influenza outbreaks.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Antibodies, Viral
- B7-1 Antigen
- B7-2 Antigen
- Female
- Hemagglutination Inhibition Tests
- Humans
- Immunization
- Influenza A Virus, H1N1 Subtype
- Influenza A Virus, H3N2 Subtype
- Influenza B virus
- Influenza Vaccines
- Influenza, Human
- Male
- Monocytes
- Predictive Value of Tests
Neonates are more susceptible than adults to viral and bacterial diseases. We hypothesized that plasmacytoid dendritic cells, the cells that provide large amounts of IFN-alpha in response to Toll-like receptor 9 (TLR9) agonists, are defective in neonates. To assess the intrinsic functionality of plasmacytoid dendritic cells from neonates we compared IFN-alpha production by plasmacytoid dendritic cells derived from neonates versus adults in both whole blood and in purified plasmacytoid dendritic cells. TLR9-stimulation of whole blood from adults and neonates resulted in comparable amounts of IFN-alpha production. However, we observed small but significant differences in IFN-alpha production from purified CD123 plasmacytoid dendritic cells from neonates after stimulation with the TLR9 ligand CpG-DNA. Furthermore, we assessed surface expression of co-stimulatory molecules on plasmacytoid dendritic cells after stimulation. While purified CD123 plasmacytoid dendritic cells from adults up-regulated co-stimulatory molecules CD80 and CD86 with IL-3 alone those from neonates required the addition of CpG-DNA to reach adult levels. Therefore, the intrinsic deficiencies of neonatal plasmacytoid dendritic cells can be mitigated by TLR9 agonists. These results are consistent with the observation that vaccines that effect strong adjuvant activity on dendritic cells can induce protective responses in neonates.
MeSH Terms
- Adult
- Aging
- B7-1 Antigen
- B7-2 Antigen
- Base Sequence
- Cell Differentiation
- Cell Separation
- Cells, Cultured
- DNA
- Dendritic Cells
- Humans
- Infant, Newborn
- Interferon-alpha
- Interleukin-3
- Interleukin-3 Receptor alpha Subunit
- Oligodeoxyribonucleotides
- Receptors, Interleukin-3
- Toll-Like Receptor 9
- Up-Regulation
We analyzed the activation and function of dendritic cells (DCs) in the spleens of diseased, lupus-prone NZM2410 and NZB-W/F1 mice and age-matched BALB/c and C57BL/6 control mice. Lupus DCs showed an altered ex vivo costimulatory profile, with a significant increase in the expression of CD40, decreased expression of CD80 and CD54, and normal expression of CD86. DCs from young lupus-prone NZM2410 mice, before the development of the disease, expressed normal levels of CD80 and CD86 but already overexpressed CD40. The increase in CD40-positive cells was specific for DCs and involved the subset of myeloid and CD8alpha DCs before disease onset, with a small involvement of plasmacytoid DCs in diseased mice. In vitro data from bone marrow-derived DCs and splenic myeloid DCs suggest that the overexpression of CD40 is not due to a primary alteration of CD40 regulation in DCs but rather to an extrinsic stimulus. Our analyses suggest that the defect of CD80 in NZM2410 and NZB-W/F1 mice, which closely resembles the costimulatory defect found in DCs from humans with systemic lupus erythematosus, is linked to the autoimmune disease. The increase in CD40 may instead participate in disease pathogenesis, being present months before any sign of autoimmunity, and its downregulation should be explored as an alternative to treatment with anti-CD40 ligand in lupus.
MeSH Terms
- Aging
- Animals
- B7-1 Antigen
- B7-2 Antigen
- CD40 Antigens
- Dendritic Cells
- Disease Susceptibility
- Lupus Vulgaris
- Mice
- Mice, Inbred Strains
- Phenotype
- Severity of Illness Index
- Spleen
There is a clear decrease in CD8( ) T cell effector function with aging, a loss once thought to be intrinsic to the CD8( ) T cells. Recent studies suggest, however, that this decline may be a consequence of altered stimulatory signals within the aged lymphoid microenvironment. In this study, we compared the immune responses of young and old mice against the BM-185 pre-B cell lymphoma expressing enhanced GFP (EGFP) as a surrogate tumor Ag. Young animals develop protective immune responses when immunized with BM-185-EGFP, but aged mice do not and ultimately succumb to the tumor. However, expression of CD80 (B7.1) on the BM-185-EGFP (BM-185-EGFP-CD80) results in rejection of the tumor by both young and old animals. Additionally, injection of BM-185-EGFP-CD80 cells in young mice promotes the development of long-lasting memory responses capable of rejecting BM-185 wild-type tumors. Aged animals similarly injected did not develop antitumor memory responses. Interestingly, old animals immunized with the BM-185-EGFP-CD80 cells plus injections of the agonist anti-OX40 mAb did develop long-lasting memory responses capable of rejecting the BM-185 wild-type tumors with the same vigor as the young animals. We show that old mice have the capacity to develop strong antitumor responses and protective memory responses as long as they are provided with efficient costimulation. These results have important implications for the development of vaccination strategies in the elderly, indicating that the aged T cell repertoire can be exploited for the induction of tumor immunity.
MeSH Terms
- Adjuvants, Immunologic
- Aging
- Animals
- Antibodies, Monoclonal
- B7-1 Antigen
- CD4-Positive T-Lymphocytes
- CD8-Positive T-Lymphocytes
- Cell Line, Tumor
- Graft Rejection
- Green Fluorescent Proteins
- Immunity, Innate
- Immunologic Memory
- Injections, Subcutaneous
- Luminescent Proteins
- Lymphocyte Depletion
- Lymphoma, B-Cell
- Mice
- Mice, Inbred BALB C
- Neoplasm Transplantation
- Receptors, OX40
- Receptors, Tumor Necrosis Factor
- T-Lymphocytes, Cytotoxic
The ontogeny of the human immune system was studied by analyzing fetal and adult tissues for the presence of various lymphocyte populations and activation/maturation markers. CD95 (fas) was expressed in hematopoietic tissues during the final stages of development of monocytes, granulocytes, NK cells and T cells, but to a much lesser extent on B cells. In the periphery, CD95 expression declined on granulocytes and NK cells. CD95 was expressed at a higher level on CD45RA peripheral T-cells in the fetus than in the adult. Contrary to the belief that most fetal T-cells are naïve or resting, a notable number of CD45RO T-cells were observed as well as an unique CD95-CD45RO population. Activation markers CD25, CD122, CD69 and CD80 were also present on fetal T-cells. These findings indicate that in the initial weeks following thymic maturation, a high frequency of T-cells is activated in the periphery of the fetus.
MeSH Terms
- Adult
- Aging
- Biomarkers
- Fetus
- Flow Cytometry
- Humans
- Immunophenotyping
- Leukocyte Common Antigens
- Lymphocyte Activation
- Protein Isoforms
- Receptors, Antigen, T-Cell, alpha-beta
- Receptors, Cytokine
- T-Lymphocytes
- fas Receptor
In the present paper, we investigated whether the phenotype, the antigen-presenting capacity, and the migration of antigen-presenting cells (APCs), are affected by the aging process. APCs were obtained incubating peritoneal monocyte-macrophage cells with granulocyte-macrophage colony-stimulating factor (GM-CSF) (immature APCs) or GM-CSF and IFNgamma (mature APCs). Phenotypically, after 8 days incubation, APCs cultures were composed of CD11c and Mac-3 cells, with a similar representation, both in young and old mice. The absolute number and the expression of MHC I and II, CD80, and CD86 both on immature and mature APCs were not significantly different in young and old mice. APCs from old mice induced similar lymphocyte proliferative responses but lower lymphocyte cytotoxicity and a reduced number of CD8( ) T cells producing IFNgamma in comparison with APCs from young animals. Lymphocyte responses were antigen-specific, since TS/A pulsed APCs induced lymphocyte cytotoxicity against TS/A but not against syngeneic TUBO tumor cells. The low expression of the mRNA for the migratory CCR7 chemokine receptor present in immature APCs from old mice was greatly increased in mature APCs up to the levels found in APCs from young animals. The in vivo migration of APCs was higher in old than in young mice. These results demonstrate that some alterations in APCs function are present in aging, suggesting that an increased migratory capacity of old APCs may be required to balance their reduced antigen presentation to cytotoxic lymphocytes.
MeSH Terms
- Aging
- Animals
- Antigen-Presenting Cells
- Cell Movement
- Cytotoxicity, Immunologic
- Immunophenotyping
- Lymphocyte Activation
- Male
- Mice
- Mice, Inbred BALB C
- Phagocytosis
- Receptors, CCR7
- Receptors, Chemokine
Young mice lacking CD28 have normal numbers of peripheral B cells; however, abnormalities exist in the humoral immune response that may result from an intrinsic defect in the B cells. The goal of this study was to assess whether CD28 could be involved in the development of B cells. CD28 mRNA was detected preferentially in the fraction of bone marrow enriched for stromal cells. Flow cytometry and RT-PCR analysis demonstrated that CD28 was also expressed by primary-cultured stromal cells that supported B lymphopoiesis. Confocal microscopy revealed that in the presence of B-lineage cells, CD28 was localized at the contact interface between B cell precursors and stromal cells. In addition, CD80 was detected on 2-6% of freshly isolated pro- and pre-B cells, and IL-7 stimulation led to induction of CD86 on 15-20% of pro- and pre-B cells. We also observed that stromal cell-dependent production of B-lineage cells in vitro was greater on stromal cells that lacked CD28. Finally, the frequencies of B-lineage precursors in the marrow from young (4- to 8-wk-old) CD28(-/-) mice were similar to those in wild-type mice; however, older CD28(-/-) mice (15-19 mo old) exhibited a 30% decrease in pro-B cells and a 50% decrease in pre-B cells vs age-matched controls. Our results suggest that CD28 on bone marrow stromal cells participates in stromal-dependent regulation of B-lineage cells in the bone marrow. The localization of CD28 at the stromal cell:B cell precursor interface suggests that molecules important for T cell:B cell interactions in the periphery may also participate in stromal cell:B cell precursor interactions in the bone marrow.
MeSH Terms
- Aging
- Animals
- B-Lymphocyte Subsets
- Bone Marrow Cells
- CD28 Antigens
- Cell Communication
- Cell Differentiation
- Cell Division
- Cell Line
- Cell Lineage
- Cell Survival
- Cells, Cultured
- Female
- Ligands
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Stem Cells
- Stromal Cells
- T-Lymphocyte Subsets
The immunological function of the Langerhans cell (LC) network in neonatal skin was examined by defining the development of cutaneous immunity relative to the structure, phenotype and function of the epidermal LC network in neonatal, juvenile and adult mice. Analysis of epidermal sheets showed the presence of major histocompatibility complex (MHC) II , multilectin receptor DEC-205- cells within the epidermis of 3-day-old mice; both cell density and DEC-205 expression increased until day 14. When visualized with antibodies directed at MHC II, the network was poorly formed in 3- and 7-day-old mice, as there was a lower cell density and poor MHC II expression on dendritic processes, compared to mice at day14. Application of a fluorescent antigen to 3-day-old mice revealed that the LC were inefficient in transporting antigen to the draining lymph node. There was an improvement at day 7 and by day 14 comparable numbers of antigen carrying cells were detected in the lymph nodes of 6-week-old mice. The reduced antigen carriage in 3- and 7-day-old mice correlated with a poor contact sensitivity response. This was not simply due to failure to present antigen, but development of immunosuppression, as transfer of T cells from adult mice that were previously treated with antigen when they were 3 days old, to adult recipients resulted in antigen specific immunosuppression. Analysis of CD80 and CD86 expression showed that LC from day 3 skin expressed CD80, but not CD86 and application of antigen through this skin was inefficient in upregulating CD86. These findings indicate that when the neonatal LC network is poorly developed it is functionally immature and antigen applied through this 'functionally immature network' results in antigen specific immunosuppression.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Antigens, CD
- B7-1 Antigen
- B7-2 Antigen
- Cell Culture Techniques
- Dermatitis, Contact
- Epidermis
- Histocompatibility Antigens Class II
- Immune Tolerance
- Langerhans Cells
- Lymph Nodes
- Male
- Membrane Glycoproteins
- Mice
- Mice, Inbred BALB C
- Picryl Chloride
Dendritic cells (DC) are powerful antigen presenting cells, which have the unique capacity to stimulate naive T cells. In spite of the well-known decline of T cell function in old age, little information is available on whether DC are also affected by the aging process. This is mainly due to problems with the isolation and purification of DC. Rapid progress in the characterization of DC has been made in recent years, as simple methods to generate large numbers of DC from precursors have been developed. It was the aim of the present study to compare monocyte derived DC from old and young healthy persons. The generation of DC from blood monocytes in response to GM-CSF and IL-4 treatment was similar in cells from young and old persons. The DC population thus obtained had a typical dendritic morphology and expressed DC surface markers, such as HLA class II, CD1a, CD11c, CD54, CD80 and CD86, but not CD14 for a period of up to three weeks in culture. DC from young and old persons produced IL-12 and TNF-alpha and responded equally well to maturation-inducing stimuli. DC maturation was stimulated by purified protein derivative (PPD) of Mycobacterium tuberculosis, whole inactivated influenza virus and by influenza split vaccine, but not by purified viral RNA. When tested for their antigen-presenting capacity, DC from young and old persons were capable of stimulating the proliferation and the cytokine production of T cells. It was of particular interest that CD45RA( ) as well as CD45RO( ) T cells from aged donors were unable to respond to stimulation with influenza proteins presented by monocytes, but were triggered to proliferate and to produce cytokines when antigen was presented by DC. The results demonstrate that DC from old persons (a) may still function as powerful antigen-presenting cells provided the right differentiation and maturation stimuli are present; (b) are capable of mobilizing residual capacity in senescent T cells and (c) may therefore represent a potent tool for immunotherapy and vaccines in old age.
MeSH Terms
- Adult
- Aged
- Aging
- Antigens, Differentiation
- Cell Communication
- Cell Differentiation
- Cytokines
- Dendritic Cells
- Granulocyte-Macrophage Colony-Stimulating Factor
- Humans
- In Vitro Techniques
- Interleukin-4
- Lymphocyte Activation
- Monocytes
- Phenotype
- T-Lymphocytes
Ageing is associated with a decline in immune function and our primary objective is to 'reverse' age-related decline in protective immune responses to vaccination by formulating vaccines in appropriate delivery systems. In this paper, we demonstrate that influenza vaccine formulated as ISCOMs is highly immunogenic and confers protection in aged mice, when compared to current influenza vaccine. The enhanced protection conferred by Flu-ISCOMs in aged mice correlates with the up-regulation of co-stimulatory molecule, CD86 (B7.2) and to a lesser extent, CD80 (B7.1) expression on antigen presenting cells.
MeSH Terms
- Aging
- Animals
- Antigens, CD
- B7-1 Antigen
- B7-2 Antigen
- CD28 Antigens
- Enzyme-Linked Immunosorbent Assay
- Hemagglutination Inhibition Tests
- ISCOMs
- Immunity, Innate
- Influenza Vaccines
- Membrane Glycoproteins
- Mice
- Mice, Inbred DBA
- Retroelements
- Up-Regulation
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. alphaCD72 ligation increased cord B cell activation and IgM production, but did not affect adult B cells. Blocking alphaCD40 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-CD40L 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 alphaCD72 significantly increased cord B cell Ig production over that in the presence of either alphaCD72 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