CD59
CD59 glycoprotein precursor (1F5 antigen) (20 kDa homologous restriction factor) (HRF-20) (HRF20) (MAC-inhibitory protein) (MAC-IP) (MEM43 antigen) (Membrane attack complex inhibition factor) (MACIF) (Membrane inhibitor of reactive lysis) (MIRL) (Protectin) (CD59 antigen) [MIC11] [MIN1] [MIN2] [MIN3] [MSK21]
Publications[править]
A subset of the red blood cells (RBCs) of patients with paroxysmal nocturnal hemoglobinuria (PNH) lacks GPI-anchored proteins. Some of these proteins, such as CD59, inhibit complement activation and protect against complement-mediated lysis. This pathology thus provides the possibility to explore the involvement of complement in red blood cell homeostasis and the role of GPI-anchored proteins in the generation of microvesicles (MVs) [i]in vivo[/i]. Detailed analysis of morphology, volume, and density of red blood cells with various CD59 expression levels from patients with PNH did not provide indications for a major aberration of the red blood cell aging process in patients with PNH. However, our data indicate that the absence of GPI-anchored membrane proteins affects the composition of red blood cell-derived microvesicles, as well as the composition and concentration of platelet-derived vesicles. These data open the way toward a better understanding on the pathophysiological mechanism of PNH and thereby to the development of new treatment strategies.
Keywords
- aging
- microvesicles
- paroxysmal nocturnal hemoglobinuria
- red blood cells
- thrombosis
The complement system is closely linked to the pathogenesis of AMD. Several complement genes are expressed in RPE, and complement proteins accumulate in drusen. Further, a common variant of complement factor H (CFH) confers increased risk of developing AMD. Because the mechanisms by which changes in the function of CFH influence development of AMD are unclear, we examined ocular complement expression as a consequence of age in control and CFH null mutant mice. Gene expression in neuroretinas and RPE/choroid from young and aged WT and Cfh(-/-) C57BL/6J mice was analyzed by microarrays. Expression of a wide range of complement genes was compared with expression in liver. An age-associated increased expression of complement, particularly C1q, C3, and factor B, in the RPE/choroid coincided with increased expression of the negative regulators Cfh and Cd59a in the neuroretina. Young mice deficient in CFH expressed Cd59a similar to WT, but failed to upregulate Cd59a expression with age. Hepatic expression of Cd59a increased with age regardless of Cfh genotype. While the connection between CFH deficiency and failure to upregulate CD59a remains unknown, these results suggest that expression of CD59 is tissue-specific and that neuroretinal regulation depends on CFH. This could contribute to the visual functional deficits and morphological changes in the Cfh(-/-) mouse retina that occur with age.
MeSH Terms
- Aging
- Animals
- CD59 Antigens
- Choroid
- Complement Factor H
- Genotype
- Hereditary Complement Deficiency Diseases
- Kidney Diseases
- Macular Degeneration
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Retina
- Retinal Drusen
- Retinal Pigment Epithelium
- Transcriptome
Age-related macular degeneration (AMD) is the commonest cause of blindness in Western populations. Risk is influenced by age, genetic and environmental factors. Complement activation appears to be important in the pathogenesis and associations have been found between AMD and genetic variations in complement regulators such as complement factor H. We therefore investigated other complement regulators for association with AMD. We carried out a case-control study to test for association between AMD and single nucleotide polymorphisms (SNPs) spanning the genes encoding complement factor P (CFP, properdin), CD46 (membrane cofactor protein, MCP), CD55 (decay accelerating factor, DAF) and CD59 (protectin). All cases and controls were examined by an ophthalmologist and had independent grading of fundus photographs to confirm their disease status. 20 SNPs were genotyped in 446 cases and 262 controls. For two SNPs with p-values approaching significance additional subjects were genotyped to increase the numbers to 622 cases and 359 controls. There was no evidence of association between AMD and any of the SNPs typed in CFP, CD46, CD55 or CD59. In a case-control sample that has shown the well established associations between AMD and variants in CFH, CFB and C3 there was absence of association with SNPs in CFP, CD46, CD55 and CD59. This suggests that these are not important susceptibility genes for AMD.
MeSH Terms
- Aged
- Aged, 80 and over
- Aging
- CD55 Antigens
- CD59 Antigens
- Case-Control Studies
- Complement System Proteins
- Female
- Genetic Association Studies
- Genetic Predisposition to Disease
- Genetic Variation
- Genotype
- Humans
- Macular Degeneration
- Male
- Membrane Cofactor Protein
- Polymorphism, Single Nucleotide
- Properdin
Complement-mediated damage to the retinal pigment epithelium (RPE), Bruch membrane, and choroid has been associated with pathogenesis in age-related macular degeneration (AMD). The terminal step of complement activation involves lysis of cells by the insertion of the membrane attack complex (MAC) in the plasma membrane. The hypothesis that local overexpression of human CD59 (hCD59) delivered by an adenovirus (Ad) vector to primary murine RPE cells in vitro, RPE in vivo, or cornea ex vivo protects those cells from human MAC deposition and lysis was tested. A humanized model of MAC deposition on murine cells and murine ocular tissues including RPE and cornea was developed to permit testing of human complement regulators in mice. A recombinant adenovirus-expressing hCD59 was generated, and this virus was injected into the subretinal space of adult mice. Subsequently, eyecups from these mice were exposed to human serum, and the levels of MAC deposition on the RPE were quantified. hCD59 was also expressed on murine cornea ex vivo and in murine hepatocytes, and primary RPE cells in vitro and levels of human MAC deposition and cell lysis were measured. Adenovirus-mediated delivery of hCD59 to the RPE, cornea, or cells in culture protects those cells from human MAC deposition and MAC-mediated damage and vesiculation. The humanized model of MAC deposition on murine ocular tissues allows testing of human complement regulators that may have potential in the treatment of AMD or other diseases associated with complement activation.
MeSH Terms
- Adenoviridae
- Adult
- Aging
- Animals
- CD59 Antigens
- Cell Culture Techniques
- Cell Line
- Complement Membrane Attack Complex
- Embryo, Mammalian
- Flow Cytometry
- Genetic Vectors
- Humans
- Macular Degeneration
- Mice
- Mice, Inbred C57BL
- Models, Biological
- Pigment Epithelium of Eye
To characterize the distribution of membrane-bound components of the complement system in normal human retina, eyes from eight human donors with no history of ocular disease, ranging in age from 47 to 85 years were examined using immunohistochemistry to localize the C3a receptor (C3aR), C5a receptor (C5aR), CD46, CD55, and CD59 in cryosections prepared from donor posterior segments. The C3aR was identified in the nerve fiber layer in a sawtooth-patterned band. Vimentin, used as a Müller cell marker, produced a similar staining pattern. The C5aR was detected on specific rounded structures in the inner plexiform layer and occasionally in the nerve fiber layer. CD46 produced markedly specific staining of the basolateral surface of the retinal pigment epithelium. CD55 was localized to the nerve fiber layer. Staining for these proteins was consistent across all eyes studied. CD59 was expressed throughout the nerve fiber layer and labeled vessels that extended through the ganglion cell, inner plexiform, and inner nuclear layers, but this pattern was only confirmable in a single subject. Complement anaphylatoxin receptors and regulatory proteins are localized in different but internally consistent patterns in normal adult human retina, independent of the age of the donor. C3aR and C5aR localization only in the inner retina contrasts with previously reported findings in the central nervous system of wide spread diffuse staining. The complement regulators CD55 and CD59 were found primarily on the inner retina, while CD46 was present exclusively in a polarized fashion on the RPE.
MeSH Terms
- Aged
- Aged, 80 and over
- Aging
- CD55 Antigens
- CD59 Antigens
- Complement C3
- Female
- Humans
- Immunoenzyme Techniques
- Male
- Membrane Cofactor Protein
- Membrane Proteins
- Middle Aged
- Pigment Epithelium of Eye
- Receptor, Anaphylatoxin C5a
- Receptors, Complement
- Retina
Multipotent cells were isolated from the dermis of newborn rats by their adherence to plastic culture dishes. Morphological observations showed that most of these elements were fibroblast-like cells described as cultured dermal multipotent cells (DMCs). These cells express CD90, CD44, CD59, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). They display the capacity to differentiate into cells with the phenotypic properties of osteocytes, adipocytes, chondrocytes, or neurons depending upon the specific inducing media. The confluent dermal multipotent cell layer supported and promoted the in vitro growth of colony-forming unit of granulocyte/macrophage progenitors (CFU-GM) as well as hematopoietic progenitor colonies. Transplantation of dermal multipotent cells into sublethally irradiated rats led to a significant increase of peripheral blood white cells nucleated cells, and CFU-GM colonies in the bone marrow. Fluorescence in situ hybridization analysis using a Y-chromosome-specific probe showed that dermal multipotent cells could engraft into bone marrow. However, they failed to differentiate into CD45-positive hematopoietic cells and to repopulate the hematopoietic system of lethally irradiated rats. These results suggest that plastic-adherent DMCs may at least represent an alternative source of mesenchymal stem cells to restore the marrow microenvironment and promote the survival, engraftment, and proliferation of hematopoietic cells.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Cell Differentiation
- Colony-Forming Units Assay
- Female
- Gamma Rays
- Granulocytes
- Immunosuppression
- In Situ Hybridization, Fluorescence
- Leukocyte Count
- Leukocytes
- Macrophages
- Rats
- Rats, Wistar
- Skin Transplantation
- Stem Cell Transplantation
- X-Rays
Few theories have been advanced for the production of corpora amylacea (CA) by the normal ageing brain and by the CNS under various neurological conditions. Proteins derived from neurons and oligodendrocytes are found in CA and to understand their origins brain tissue from patients with Alzheimer's disease (AD), multiple sclerosis (MS) and Pick's disease (PD) were tested for complement activity. All CA were immunopositive for antisera to classical pathway-specific components, the activation products C3d and the terminal complement complex (TCC), the C3 convertase regulator membrane cofactor protein (MCP) and the fluid phase regulators S-protein and clusterin. CA were immunonegative for the alternative complement pathway proteins and the complement regulators, decay accelerating factor (DAF) and CD59. Western immunoblotting of isolated solubilized CA from the same tissues demonstrated a weak band for MCP but TCC was more easily shown by immunoprecipitation. A filamentous fringe around CA, probably of astrocytic origin, was also immunopositive for complement factors. CA consist of an inert mucopolysaccharide matrix encasing ubiquitinated proteins, resulting from death of and damage to neurons, myelin and oligodendrocytes. A function of CA, therefore, could be to prevent the recognition of these immunogenic proteins by lymphocytes and microglia and thus protect the CNS from further injury.
MeSH Terms
- Aging
- Alzheimer Disease
- Case-Control Studies
- Complement System Proteins
- Dementia
- Electrophoresis, Polyacrylamide Gel
- Hippocampus
- Humans
- Immunoblotting
- Microscopy, Immunoelectron
- Multiple Sclerosis
- Precipitin Tests
- Reference Values
The human fetus appears to be capable of protecting itself from maternal complement (C) from an early stage in development by expressing the C regulatory proteins decay-accelerating factor (DAF), membrane co-factor protein (MCP) and CD59 on fetally derived trophoblast at the feto-maternal interface. In this study we have examined the ontogeny of these proteins within the fetus itself and have focused on the liver which represents a major site of haemopoiesis during development. Immunostaining revealed that DAF, MCP and CD59 are all expressed from at least 6 weeks of gestation in the liver but that these proteins display distinct distribution patterns. CD59 was broadly distributed both within the epithelial and haemopoietic compartments, but expression of C3 convertase regulators was more restricted. DAF expression was limited to isolated cells within haemopoietic nests and the epithelium was DAF-negative. Although MCP expression on haemopoietic cells was also limited, by contrast with DAF the developing hepatic epithelium was strongly MCP-positive. Typical CD59 and MCP components were observed in fetal liver extracts by immunoblotting, although liver MCP components consistently migrated 4000-5000 MW ahead of those observed on placental trophoblast. Differences in the distribution of these proteins were also observed between the fetal and adult liver. In particular, by comparison with fetal hepatic epithelium, there was an apparent loss of MCP expression from adult hepatocytes. Thus, MCP appears to be developmentally regulated in the human liver and is expressed in the absence of DAF on the early hepatic epithelium. Overall, this study suggests that C regulatory proteins, and in particular CD59 and MCP, are required from the very early stages of gestation within the fetus itself.
MeSH Terms
- Adult
- Aging
- Antigens, CD
- Blotting, Western
- CD55 Antigens
- CD59 Antigens
- Complement Inactivator Proteins
- Complement System Proteins
- Humans
- Immunoenzyme Techniques
- Liver
- Membrane Cofactor Protein
- Membrane Glycoproteins