1
|
Wu B, Ouyang Z, Lyon CJ, Zhang W, Clift T, Bone CR, Li B, Zhao Z, Kimata JT, Yu XG, Hu Y. Plasma Levels of Complement Factor I and C4b Peptides Are Associated with HIV Suppression. ACS Infect Dis 2017; 3:880-885. [PMID: 28862830 PMCID: PMC5727467 DOI: 10.1021/acsinfecdis.7b00042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
![]()
Individuals who exhibit long-term
HIV suppression and CD4 T-cell preservation without antiretroviral
therapy are of great interest for HIV research. There is currently
no robust method for rapid identification of these “HIV controller”
subjects; however, HLA-B*57 (human leukocyte antigen (major histocompatibility
complex), class I, B*57) genotype exhibits modest sensitivity for
this phenotype. Complement C3b and C4b can influence HIV infection
and replication, but studies have not examined their possible link
to HIV controller status. We analyzed HLA-B*57 genotype and complement
levels in HIV-positive patients receiving suppressive antiretroviral
therapy, untreated HIV controllers, and HIV-negative subjects to identify
factors associated with HIV controller status. Our results revealed
that the plasma levels of three C4b-derived peptides and complement
factor I outperformed all other assayed biomarkers for HIV controller
identification, although we could not analyze the predictive value
of biomarker combinations with the current sample size. We believe
this rapid screening approach may prove useful for improved identification
of HIV controllers.
Collapse
Affiliation(s)
- Boyue Wu
- Biodesign Center
for Personalized Diagnostics, the Biodesign Institute, Arizona State University, 727 E. Tyler Street, Tempe, Arizona 85281, United States
- College of Laboratory Medicine, Tianjin Medical University, 1 Guangdong Road, Tianjin 300203, China
| | - Zhengyu Ouyang
- Ragon Institute of MGH, MIT and Harvard University, 400 Technology Square, Boston, Massachusetts 02139-3583, United States
| | - Christopher J. Lyon
- Biodesign Center
for Personalized Diagnostics, the Biodesign Institute, Arizona State University, 727 E. Tyler Street, Tempe, Arizona 85281, United States
- Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States
| | - Wei Zhang
- Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States
- Shengjing Hospital of China Medical University, 36 Sanhao Street, Heping District, Shenyang, Liaoning 110003, China
| | - Tori Clift
- Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States
| | - Christopher R. Bone
- Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States
| | - Boan Li
- Center for Clinical Laboratory, 302 Military Hospital of China, 100 Middle Section of West 4th Ring Road, Beijing 100038, China
| | - Zhen Zhao
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Jason T. Kimata
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, United States
| | - Xu G. Yu
- Ragon Institute of MGH, MIT and Harvard University, 400 Technology Square, Boston, Massachusetts 02139-3583, United States
| | - Ye Hu
- Biodesign Center
for Personalized Diagnostics, the Biodesign Institute, Arizona State University, 727 E. Tyler Street, Tempe, Arizona 85281, United States
- Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States
- School of Biological and Health Systems
Engineering, Virginia G. Piper, Arizona State University, 727
E. Tyler Street, Tempe, Arizona 85281, United States
| |
Collapse
|
2
|
Plasmodium falciparum uses a key functional site in complement receptor type-1 for invasion of human erythrocytes. Blood 2011; 118:1923-33. [PMID: 21685372 DOI: 10.1182/blood-2011-03-341305] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Plasmodium falciparum adhesin PfRh4 binds to complement receptor type-1 (CR1) on human erythrocytes and mediates a glycophorin-independent invasion pathway. CR1 is a complement regulator and immune-adherence receptor on erythrocytes required for shuttling of C3b/C4b-opsonized particles to liver and spleen for phagocytosis. Using recombinant CR1 constructs, we mapped the recognition site for PfRh4 to complement control protein modules 1 to 3 (CCP1-3) at the membrane-distal amino terminus of CR1. This region of CR1 binds to C4b and C3b and accelerates decay of both classic pathway and alternative pathway C3 and C5 convertases. CCP1-3 competed for PfRh4 binding to erythroid CR1 and inhibited the PfRh4-CR1 invasion pathways across a wide range of P falciparum strains. PfRh4 did not bind significantly to other CR1 constructs, including CCP15-17, which is 85% identical to CCP1-3. PfRh4 binding to CR1 did not affect its C3b/C4b binding capability, and we show evidence for a ternary complex between CCP1-3, C4b, and PfRh4. PfRh4 binding specifically inhibited CR1's convertase decay-accelerating activity, whereas there was no effect on factor H-mediated decay-accelerating activity. These results increase our understanding of the functional implications of CR1 engagement with PfRh4 and highlight the interplay between complement regulation and infection.
Collapse
|
3
|
Willey S, Aasa-Chapman MMI, O'Farrell S, Pellegrino P, Williams I, Weiss RA, Neil SJD. Extensive complement-dependent enhancement of HIV-1 by autologous non-neutralising antibodies at early stages of infection. Retrovirology 2011; 8:16. [PMID: 21401915 PMCID: PMC3065417 DOI: 10.1186/1742-4690-8-16] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 03/14/2011] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Non-neutralising antibodies to the envelope glycoprotein are elicited during acute HIV-1 infection and are abundant throughout the course of disease progression. Although these antibodies appear to have negligible effects on HIV-1 infection when assayed in standard neutralisation assays, they have the potential to exert either inhibitory or enhancing effects through interactions with complement and/or Fc receptors. Here we report that non-neutralising antibodies produced early in response to HIV-1 infection can enhance viral infectivity. RESULTS We investigated this complement-mediated antibody-dependent enhancement (C'-ADE) of early HIV infection by carrying out longitudinal studies with primary viruses and autologous sera derived sequentially from recently infected individuals, using a T cell line naturally expressing the complement receptor 2 (CR2; CD21). The C'-ADE was consistently observed and in some cases achieved infection-enhancing levels of greater than 350-fold, converting a low-level infection to a highly destructive one. C'-ADE activity declined as a neutralising response to the early virus emerged, but later virus isolates that had escaped the neutralising response demonstrated an increased capacity for enhanced infection by autologous antibodies. Moreover, sera with autologous enhancing activity were capable of C'ADE of heterologous viral isolates, suggesting the targeting of conserved epitopes on the envelope glycoprotein. Ectopic expression of CR2 on cell lines expressing HIV-1 receptors was sufficient to render them sensitive to C'ADE. CONCLUSIONS Taken together, these results suggest that non-neutralising antibodies to the HIV-1 envelope that arise during acute infection are not 'passive', but in concert with complement and complement receptors may have consequences for HIV-1 dissemination and pathogenesis.
Collapse
Affiliation(s)
- Suzanne Willey
- MRC/UCL Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, 46 Cleveland Street, London W1T 4JF, UK
- Department of Infectious Diseases, King's College London, Peter Gorer Department of Immunobiology, Borough Wing, Guy's Hospital, London SE1 9RT, UK
| | - Marlén MI Aasa-Chapman
- MRC/UCL Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, 46 Cleveland Street, London W1T 4JF, UK
| | - Stephen O'Farrell
- Centre for Sexual Health and HIV Research, University College London, UK
| | - Pierre Pellegrino
- Centre for Sexual Health and HIV Research, University College London, UK
| | - Ian Williams
- Centre for Sexual Health and HIV Research, University College London, UK
| | - Robin A Weiss
- MRC/UCL Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, 46 Cleveland Street, London W1T 4JF, UK
| | - Stuart JD Neil
- MRC/UCL Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, 46 Cleveland Street, London W1T 4JF, UK
- Department of Infectious Diseases, King's College London, Peter Gorer Department of Immunobiology, Borough Wing, Guy's Hospital, London SE1 9RT, UK
| |
Collapse
|
4
|
Complement-HIV interactions during all steps of viral pathogenesis. Vaccine 2007; 26:3046-54. [PMID: 18191309 DOI: 10.1016/j.vaccine.2007.12.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 11/27/2007] [Accepted: 12/01/2007] [Indexed: 01/24/2023]
Abstract
Upon crossing the endothelial barrier of the host, HIV initiates immediate responses of the immunity system. Among its components, the complement system is one of the first the first elements, which are activated to affect HIV propagation. Complement participates not only in the early phase of the immune response, but its effects can be observed continuously and also concern the induction and modification of the adaptive immune response. Here we discuss the role of complement in early and late stages of HIV pathogenesis and review the escape mechanisms, which protect HIV from destruction by the complement system.
Collapse
|
5
|
Speth C, Dierich MP, Sopper S. HIV-infection of the central nervous system: the tightrope walk of innate immunity. Mol Immunol 2005; 42:213-28. [PMID: 15488609 DOI: 10.1016/j.molimm.2004.06.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Infection of the central nervous system (CNS) by HIV is a frequent and sometimes very early event in the course of HIV pathogenesis. Possible consequences are diverse symptoms of neurological dysfunction, but also the establishment of a lifelong latent viral reservoir in the brain. Whereas in the periphery innate and adaptive immunity are equal partners, the blood-brain barrier (BBB) with its restricted access of peripheral immune effectors shifts this balance in favour of the local innate immunity. Four main elements of cerebral innate immunity are discussed in the present article, including two cell types with immunological functions and two soluble immune systems: (1) the stimulation of microglial cells as the predominant brain-resident immune cell and the main local reservoir for the virus; (2) the reaction of astrocytes in response to viral infection; (3) the activation of the local complement system as important soluble immune cascade; and (4) the role of chemokines and cytokines which help to conduct and cross-link the interplay between the different immune elements. These components of the cerebral innate immunity do not act separately from each other but form a functional immunity network. A dual role of these components with both harmful and protective effects further enhances the complexity of the mutual interactions.
Collapse
Affiliation(s)
- Cornelia Speth
- Institute of Hygiene and Social Medicine, Medical University Innsbruck and Ludwig-Boltzmann-Institute for AIDS Research, Fritz-Pregl-Str. 3, A-6020 Innsbruck, Austria.
| | | | | |
Collapse
|
6
|
Speth C, Williams K, Hagleitner M, Westmoreland S, Rambach G, Mohsenipour I, Schmitz J, Würzner R, Lass-Flörl C, Stoiber H, Dierich MP, Maier H. Complement synthesis and activation in the brain of SIV-infected monkeys. J Neuroimmunol 2004; 151:45-54. [PMID: 15145603 DOI: 10.1016/j.jneuroim.2004.02.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 01/12/2004] [Accepted: 02/19/2004] [Indexed: 11/25/2022]
Abstract
Complement is one of the most critical defence tools against cerebral infections, but uncontrolled complement biosynthesis and activation can induce profound brain tissue damage. To clarify the role of complement in the pathogenesis of AIDS-associated neurological disorders, we analysed the synthesis of complement in the brains of SIV-infected rhesus macaques. Using immunohistochemical staining we could show that the cerebral synthesis of complement factors C1q and C3 was strongly upregulated in SIV-infected monkeys compared to the spontaneous synthesis in uninfected control monkeys. Astrocytes, neurons, microglia, infiltrating macrophages and multinuclear giant cells all contribute to the high amounts of C1q and C3 in the brain. Secreted C1q and C3 are also deposited on the membrane of neurons, a prerequisite for formation of the membrane-driven lytic membrane attack complex. The membrane deposition thus might suggest complement-induced lysis of bystander neurons as a potential mechanism for cell damage during viral infection of the brain.
Collapse
Affiliation(s)
- Cornelia Speth
- Institute of Hygiene and Social Medicine, Innsbruck Medical University and Ludwig-Bolthmann-Institute for AIDS Research, Fritz-Pregl-Str. 3, Innsbruck A-6020, Austria.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Sárváry A, Szucs S, Balogh I, Becsky A, Bárdos H, Kávai M, Seligsohn U, Egbring R, Lopaciuk S, Muszbek L, Adány R. Possible role of factor XIII subunit A in Fcγ and complement receptor-mediated phagocytosis. Cell Immunol 2004; 228:81-90. [PMID: 15219459 DOI: 10.1016/j.cellimm.2004.04.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2003] [Accepted: 04/12/2004] [Indexed: 11/24/2022]
Abstract
Besides its traditional role in hemostasis, factor XIII subunit A (FXIII-A) is supposed to function as a cellular transglutaminase and to be involved in certain intracellular processes, including cytoskeletal remodeling. To investigate its intracellular role, the aim of the present study was to follow changes in FXIII-A production in combination with the receptor-mediated phagocytic activities of monocytes/macrophages and to examine the phagocytic functions of monocytes in patients with FXIII-A deficiency. Human blood monocytes were isolated from the buffy coats of healthy volunteers and cultured for 4 days. The FcgammaR-mediated phagocytosis of sensitized erythrocytes (EA) and the complement receptor (CR)-mediated phagocytosis of complement-coated yeast particles were studied during monocyte/macrophage differentiation. Changes in the gene expression of FXIII-A were detected by real-time quantitative RT-PCR. FXIII-A protein production was investigated with fluorescent image analysis at single cell level and Western immunoblot analysis. Both the FcgammaR and CR-mediated phagocytosis increased during culturing, which peaked on day 3. The phagocytic activity of the cells could be markedly inhibited with monodansylcadaverine, an inhibitor of the transglutaminase-induced crosslinking of proteins. The phagocytosis of EA, complement-coated and uncoated yeast particles was found to be strongly diminished in monocytes of FXIII-A deficient patients. The phagocytic functions of cultured cells showed a change in parallel with the alterations in FXIII-A mRNA expression, as well as with that in FXIII-A in protein synthesis detected by image and Western immunoblot analyses in concert. Our results suggest that FXIII-A plays a role in the Fcgamma and complement receptor-mediated phagocytic activities of monocytes/macrophages.
Collapse
Affiliation(s)
- Attila Sárváry
- Department of Preventive Medicine, School of Public Health, Faculty of Medicine, Medical and Health Science Center, University of Debrecen, Debrecen H-4012, P.O. Box 9, Hungary
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Zorzetto M, Bombieri C, Ferrarotti I, Medaglia S, Agostini C, Tinelli C, Malerba G, Carrabino N, Beretta A, Casali L, Pozzi E, Pignatti PF, Semenzato G, Cuccia MC, Luisetti M. Complement receptor 1 gene polymorphisms in sarcoidosis. Am J Respir Cell Mol Biol 2002; 27:17-23. [PMID: 12091241 DOI: 10.1165/ajrcmb.27.1.4805] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Sarcoidosis is likely to result from exposure of genetically susceptible hosts to environmental agents. Erythrocyte (E) complement receptor 1 (CR1) is a membrane protein mediating the transport of immune complexes (ICs) to phagocytes, and at least three polymorphisms on the CR1 gene are related to erythrocyte surface density of CR1 molecules, in turn related to the rate of IC clearance from circulation. We hypothesized that sarcoidosis could be associated with increased frequency of the CR1 gene alleles coding for reduced CR1/E ratio. We studied 91 sarcoid patients and two control groups: 94 healthy volunteers and 71 patients with chronic obstructive pulmonary disease (COPD). Three polymorphic sites of CR1 gene, His1208Arg, intron 27 HindIII/RFLP, and Pro1827Arg, were analyzed. The three polymorphisms were in linkage disequilibrium. The GG genotype for the Pro1827Arg (C(5507)G) polymorphism was significantly associated with sarcoidosis in comparison to both control groups (odds ratio [OR] = 3.13; 95% confidence interval [CI] 1.49-6.69 versus healthy control subjects, and OR= 2.82, 95% CI 1.27-6.39 versus COPD control subjects). The same genotype was particularly associated to disease in females (OR = 7.05; 95% CI 3.10-16.61 versus healthy control subjects). These findings agree with speculations on the role of CR1 gene as a possible susceptibility factor.
Collapse
Affiliation(s)
- Michele Zorzetto
- Laboratorio di Biochimica e Genetica, Clinica di Malattie dell'Apparato Respiratorio, Pavia, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Speth C, Schabetsberger T, Mohsenipour I, Stöckl G, Würzner R, Stoiber H, Lass-Flörl C, Dierich MP. Mechanism of human immunodeficiency virus-induced complement expression in astrocytes and neurons. J Virol 2002; 76:3179-88. [PMID: 11884542 PMCID: PMC136041 DOI: 10.1128/jvi.76.7.3179-3188.2002] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cerebral complement system is hypothesized to contribute to neurodegeneration in the pathogenesis of AIDS-associated neurological disorders. Our former results have shown that the human immunodeficiency virus (HIV) strongly induces the synthesis of complement factor C3 in astrocytes. This upregulation explains in vivo data showing elevated complement levels in the cerebrospinal fluid of patients with AIDS-associated neurological symptoms. Since inhibition of complement synthesis and activation in the brain may represent a putative therapeutic goal to prevent virus-induced damage, we analyzed in detail the mechanisms of HIV-induced modulation of C3 expression. HIV-1 increased the C3 levels in astrocyte culture supernatants from 30 to up to 400 ng/ml; signal transduction studies revealed that adenylate cyclase activation with upregulation of cyclic AMP is the central signaling pathway to mediate that increase. Furthermore, activity of protein kinase C is necessary for HIV induction of C3, since inhibition of protein kinase C by prolonged exposure to the phorbol ester tetradecanoyl phorbol acetate partly abolished the HIV effect. The cytokines tumor necrosis factor alpha and gamma interferon were not involved in mediating the HIV-induced C3 upregulation, since neutralizing antibodies had no effect. Besides whole HIV virions, the purified viral proteins Nef and gp41 are biologically active in upregulating C3, whereas Tat, gp120, and gp160 were not able to modulate C3 synthesis. Further experiments revealed that neurons were also able to respond on incubation with HIV with increased C3 synthesis, although the precise pattern was slightly different from that in astrocytes. This strengthens the hypothesis that HIV-induced complement synthesis represents an important mechanism for the pathogenesis of AIDS in the brain.
Collapse
Affiliation(s)
- Cornelia Speth
- Institute of Hygiene and Social Medicine, University of Innsbruck Ludwig Boltzmann Institute for AIDS Research, Innsbruck, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Affiliation(s)
- P J Klasse
- Imperial College School of Medicine, Jefferiss Research Trust Laboratories, Wright-Fleming Institute, St. Mary's Hospital, Norfolk Place, London W2 1PG, UK
| | | |
Collapse
|
11
|
Affiliation(s)
- M J Walport
- Division of Medicine, Imperial College of Science, Technology and Medicine, London, United Kingdom.
| |
Collapse
|
12
|
Bouhlal H, Galon J, Kazatchkine MD, Fridman WH, Sautès-Fridman C, Haeffner Cavaillon N. Soluble CD16 inhibits CR3 (CD11b/CD18)-mediated infection of monocytes/macrophages by opsonized primary R5 HIV-1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:3377-83. [PMID: 11207294 DOI: 10.4049/jimmunol.166.5.3377] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We demonstrate that soluble CD16 (sCD16; soluble Fc gamma RIII), a natural ligand of CR3, inhibits the infection of monocytes by primary R5 HIV-1 strain opsonized with serum of seronegative individuals. Inhibition of monocyte infection by sCD16 was similar to that observed with anti-CR3 mAbs, indicating that opsonized HIV may use a CR3-dependent pathway for entry in monocytic cells. Cultured human monocytes express both CR3 (CD11b/CD18) and CCR5 receptors. RANTES, the natural ligand of CCR5, inhibited infection of monocytes with unopsonized HIV particles and partially that of monocytes infected with HIV particles opsonized with complement-derived fragments. Although HIV-infected monocytes from homozygous CCR5 Delta 32/Delta 32 (CCR5(-/-)) individuals produce low levels of p24, cells infected with opsonized particles produced higher levels of p24 than cells infected with unopsonized particles. Our results thus suggest that CR3 may represent an alternative coreceptor to CCR5 of opsonized primary R5 virus entry into monocytes/macrophages. We also observed that the concentration of sCD16 is greatly decreased in sera of HIV-infected patients with low lymphocyte CD4(+) counts. Taken together, our findings suggest that sCD16, present in plasma, may play an important role in controlling HIV-1 spread.
Collapse
Affiliation(s)
- H Bouhlal
- Institut National de la Santé et de la Recherche Médicale Unité 430, Hôpital Broussais, Paris, France
| | | | | | | | | | | |
Collapse
|
13
|
Tolnay M, Tsokos GC. Complement receptor 2 in the regulation of the immune response. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1998; 88:123-32. [PMID: 9714689 DOI: 10.1006/clin.1998.4552] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Antigens coated with split products of C3, the result of complement activation, are capable of crosslinking the complement receptor 2 (CR2, CD21) and the antigen receptor on the surface of B cells simultaneously. This dual recognition leads to increased cell proliferation and differentiation and enhanced antibody production. CR2 is also considered to be a regulator of the B cell response to antigen. In this review we summarize the biology of the CR2 and focus on its essential role in generating an effective B cell response to antigenic stimuli. The involvement of CR2 in the pathophysiology of infectious and autoimmune diseases is also discussed.
Collapse
Affiliation(s)
- M Tolnay
- Department of Clinical Physiology, Walter Reed Army Institute of Research, Washington, DC, 20307, USA
| | | |
Collapse
|