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Sun L, Zhou L, Chen M, Zhong R, Liu J. Amelioration of systemic lupus erythematosus by Withangulatin A in MRL/lpr mice. J Cell Biochem 2011; 112:2376-82. [PMID: 21520246 DOI: 10.1002/jcb.23160] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We have previously reported the anti-inflammatory potential and the possible underlying mechanisms of Withangulatin A (WA), which is an active component isolated from Physalis angulata L. Here, we demonstrated that WA might improve the life quality, as well as reduced the accumulation of proteinuria symptoms and levels of anti-double-stranded DNA antibodies in MRL/lpr mice. Moreover, WA could improve renal histopathologic characteristics of MRL/lpr mice. Intriguingly, expression of B cell-activating factor (BAFF), BAFF-R and related gene in the spleen were significantly reduced in 10 mg/kg WA-treated mice compared with that in 5 mg/kg WA-treated mice and untreated mice. These findings indicate that WA might have a pleiotropic therapeutic effect through their immunosuppression via inhibiting BAFF signaling, which suggest a potential application of this active constituent in the treatment of SLE.
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Affiliation(s)
- Lijuan Sun
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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2
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Abstract
There has been renewed interest in the B cell as a target for the treatment of rheumatoid arthritis (RA) over the past decade. Efficacy with rituximab has been demonstrated in randomised clinical trials (RCTs) resulting in regulatory approval for patients failing tumour necrosis factor (TNF) inhibitors. Although the actual mechanism of action has not been clearly delineated, several molecules are under development to modify B cell number/function in hope of superior efficacy/safety or ease of administration. The safety of rituximab over the intermediate time point has been comparable to that seen with other biologic disease-modifying anti-rheumatic drugs (DMARDs). The recent report of cases of progressive multifocal leukoencephalopathy in three patients receiving rituximab for RA is a concern and, for now, limits rituximab to salvage therapy for the treatment-resistant patient. How this impacts on other B-cell inhibitors under development is not yet clear. Development of biomarkers that will assist our therapeutic decisions to enhance the benefit/risk ratio for our patients are needed as we move forward with further selective targeted therapies.
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Affiliation(s)
- Stanley B Cohen
- Metroplex Clinical Research Center, 8144 Walnut Hill Lane, Suite 800, Dallas TX 75231, USA
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3
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Donor CD8 T cell activation is critical for greater renal disease severity in female chronic graft-vs.-host mice and is associated with increased splenic ICOS(hi) host CD4 T cells and IL-21 expression. Clin Immunol 2010; 136:61-73. [PMID: 20451460 DOI: 10.1016/j.clim.2010.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 01/12/2010] [Indexed: 12/21/2022]
Abstract
Lupus-like renal disease in DBA/2-into-F1 (DBA --> F1) mice is driven by donor CD4 T cells and is more severe in females. Donor CD8 T cells have no known role. As expected, we observed that females receiving unfractionated DBA splenocytes (CD8 intact --> F1) exhibited greater clinical and histological severities of renal disease at 13 weeks compared to males. Surprisingly, sex-based differences in renal disease severity were lost in CD8 depleted --> F1 mice due to an improvement in females and a worsening in males. CD8 intact --> F1 female mice exhibited significantly greater donor and host effector (CD44(hi), CD62L(lo)) CD4 T cells and ICOS(hi) CD4 T follicular helper cells than males. CD8 depleted --> F1 female mice exhibited a reduction in the absolute numbers of host, but not donor CD4 Tfh cells and lost the significant increase in host CD4 effector cells vs. males. Greater female IL-21 expression, a product of Tfh cells, was seen in CD8 intact --> F1 and although reduced was still greater than male CD8 depleted --> F1 mice. Thus, donor CD8 T cells have a critical role in mediating sex-based differences in lupus renal disease severity possibly through greater host ICOS(hi) CD4 T cell involvement.
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4
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Prevention of autoimmunity and control of recall response to exogenous antigen by Fas death receptor ligand expression on T cells. Immunity 2008; 29:922-33. [PMID: 19013083 DOI: 10.1016/j.immuni.2008.10.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 10/03/2008] [Accepted: 10/22/2008] [Indexed: 12/29/2022]
Abstract
Mice with mutations in the gene encoding Fas ligand (FasL) develop lymphoproliferation and systemic autoimmune diseases. However, the cellular subset responsible for the prevention of autoimmunity in FasL-deficient mice remains undetermined. Here, we show that mice with FasL loss on either B or T cells had identical life span as littermates, and both genotypes developed signs of autoimmunity. In addition, we show that T cell-dependent death was vital for the elimination of aberrant T cells and for controlling the numbers of B cells and dendritic cells that dampen autoimmune responses. Furthermore, we show that the loss of FasL on T cells affected the follicular dentritic cell network in the germinal centers, leading to an impaired recall response to exogenous antigen. These results disclose the distinct roles of cellular subsets in FasL-dependent control of autoimmunity and provide further insight into the role of FasL in humoral immunity.
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5
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Bobé P, Bonardelle D, Benihoud K, Opolon P, Chelbi-Alix MK. Arsenic trioxide: a promising novel therapeutic agent for lymphoproliferative and autoimmune syndromes in MRL/lpr mice. Blood 2006; 108:3967-75. [PMID: 16926289 DOI: 10.1182/blood-2006-04-020610] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
MRL/lpr mice develop a human lupuslike syndrome and, as in autoimmune lymphoproliferative syndrome (ALPS), massive lymphoproliferation due to inactivation of Fas-mediated apoptosis. Presently, no effective therapy exists for ALPS, and long term, therapies for lupus are hazardous. We show herein that arsenic trioxide (As2O3) is able to achieve quasi-total regression of antibody- and cell-mediated manifestations in MRL/lpr mice. As2O3 activated caspases and eliminated the activated T lymphocytes responsible for lymphoproliferation and skin, lung, and kidney lesions, leading to significantly prolonged survival rates. This treatment also markedly reduced anti-DNA autoantibody, rheumatoid factor, IL-18, IFN-γ, nitric oxide metabolite, TNF-α, Fas ligand, and IL-10 levels and immune-complex deposits in glomeruli. As2O3 restored cellular reduced glutathione levels, thereby limiting the toxic effect of nitric oxide, which is overproduced in MRL/lpr mice. Furthermore, As2O3 protected young animals against developing the syndrome and induced almost total disease disappearance in older affected mice, thereby demonstrating that it is a novel promising therapeutic agent for autoimmune diseases.
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Affiliation(s)
- Pierre Bobé
- Centre National de la Recherche Scientifique (CNRS), Unite Propre de Recherche (UPR) 9045, Villejuif, France.
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6
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Eisenberg R, Albert D. B-cell targeted therapies in rheumatoid arthritis and systemic lupus erythematosus. ACTA ACUST UNITED AC 2006; 2:20-7. [PMID: 16932648 DOI: 10.1038/ncprheum0042] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Accepted: 09/09/2005] [Indexed: 11/08/2022]
Abstract
B cells appear to have a central role in the immunopathogenesis of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE); both autoantibody production and B-cell anomalies are characteristic of these diseases. With the recent availability of biologic agents that can deplete B cells or block their function in vivo, it has become possible to target B cells therapeutically. Evidence strongly suggests that novel B-cell targeting agents are effective. In addition, the mechanistic specificity of B-cell targeted approaches, combined with the ability to test them in large randomized controlled trials, will provide an unprecedented opportunity to study the precise roles of B cells in the immunopathogenesis of RA and SLE. The largest volume of information is available for rituximab, a chimeric monoclonal antibody that depletes B cells by binding to the CD20 cell-surface antigen. Information from multiple investigator-sponsored trials and from off-label use suggests efficacy of this antibody in RA, SLE, and other autoimmune syndromes. Randomized controlled trials have also provided solid evidence for the efficacy of rituximab in RA and are ongoing in SLE. Other therapeutic agents supported by controlled data include cytotoxic T-lymphocyte-associated protein 4 immunoglobulin and antibodies against the interleukin-6 receptor and the B-cell survival molecule BLyS. Additional agents and targets are in earlier stages of development. The concerns about infectious complications have so far not proven to be justified. We can reasonably expect important advances in the understanding and treatment of RA and SLE in the next 5-10 years, as B-cell targeting methods become more widespread and sophisticated.
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MESH Headings
- Animals
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Murine-Derived
- Antigens, CD/immunology
- Antigens, CD20/immunology
- Arthritis, Rheumatoid/drug therapy
- Arthritis, Rheumatoid/immunology
- Autoantibodies/immunology
- Autoimmune Diseases/immunology
- B-Lymphocytes/immunology
- Humans
- Leukocyte Reduction Procedures/methods
- Lupus Erythematosus, Systemic/drug therapy
- Lupus Erythematosus, Systemic/immunology
- Peptides, Cyclic/immunology
- Rituximab
- Sialic Acid Binding Ig-like Lectin 2/immunology
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Affiliation(s)
- Robert Eisenberg
- Medicine and Pathology, University of Pennsylvania, School of Medicine, Philadelphia 19104-6160, USA.
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7
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LIU SHIQUAN, CERUTTI ANDREA, CASALI PAOLO, CROW MARYK. Ongoing immunoglobulin class switch DNA recombination in lupus B cells: analysis of switch regulatory regions. Autoimmunity 2005; 37:431-443. [PMID: 15621569 PMCID: PMC4624307 DOI: 10.1080/08916930400010611] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Inflammation and tissue damage in systemic lupus erythematosus (SLE) are mediated by class-switched autoantibodies reactive with nucleic acids, nucleic acid-binding proteins, phospholipids and other self-antigens. While some healthy individuals produce IgM antibodies with specificities similar to those of lupus patients, immunoglobulin class switching to mature downstream isotypes appears to be required for the generation of pathogenic autoantibodies. To characterize the cellular and molecular basis of pathogenic autoantibody production in SLE, we studied the capacity of peripheral blood B cells of naive phenotype from patients with SLE, rheumatoid arthritis (RA) or healthy control subjects to spontaneously switch to IgG and IgA. In addition, we determined the DNA sequences of the upstream evolutionary conserved sequence (ECS)-Igamma promoter regulatory regions that control germline IH-CH transcription and class switch DNA recombination (CSR) to IgG1, IgG2 and IgG4. IgM+IgD+ B cells from patients with SLE, but not those from RA or healthy control subjects, underwent spontaneous CSR, as assessed by expression of germline Igamma1-Cgamma1, Igamma2-Cgamma2, Igamma3-Cgamma3, Igamma4-Cgamma4 and Ialpha1-Calpha1 transcripts, mature (switched) VHDJH-Cgamma1, VHDJH-Cgamma2, VHDJH-Cgamma3 and VHDJH-Calpha1 transcripts and secreted IgG and IgA. Although polymorphic DNA sequences were identified in the ECS-Igamma1, ECS-Igamma2 and ECS-Igamma4 promoter regions, the transcription factor-binding sites that mediate germline Igamma-Cgamma transcription were conserved in patients and controls. However, distinct patterns of nuclear protein binding to an ECS-Igamma promoter sequence that contains both positive and negative regulatory elements were observed in SLE patients and controls. These results support a role for exogenous signals, such as through CD40 ligation, rather than altered genomic sequence, in the increased production of class switched autoantibodies in SLE.
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Affiliation(s)
- SHIQUAN LIU
- Mary Kirkland Center for Lupus Research, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA
| | - ANDREA CERUTTI
- Departments of Pathology and Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - PAOLO CASALI
- The Center for Immunology, 3028 Hewitt Hall, University of California, Irvine, CA 92697-4120, USA
| | - MARY K. CROW
- Mary Kirkland Center for Lupus Research, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA
- Corresponding author. Tel.: +1-212-606-1397.
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8
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Mohammed JA, Mok AYP, Parbtani A, Matsell DG. Increased expression of insulin-like growth factors in progressive glomerulonephritis of the MRL/lpr mouse. Lupus 2005; 12:584-90. [PMID: 12945716 DOI: 10.1191/0961203303lu422oa] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Glomerulonephritis is an important complication of systemic lupus erythematosus (SLE). The tissue distribution and exact role of the insulin-like growth factors (IGFs) in the development of lupus nephritis in the MRL/lpr mouse model have not been established. The present study was undertaken to evaluate the changes over time in mRNA and peptide expression of IGF-I and IGFBP-2 in the MRL/lpr mouse. Using in situ hybridization and immunocytochemistry techniques, the expression of IGF-I and IGFBP-2 in MRL/lpr mouse was examined and compared to their congenic normal MRL-++ mouse counterparts from nine to 24 weeks of age. In the MRL-++ and MRL/lpr mouse kidneys, IGF-I and IGFBP-2 mRNA expression was limited to the cortical and medullary collecting ducts, while their immunoreactivity (IR) was localized to the cortical and medullary collecting ducts, loop of Henle, glomeruli and proximal tubules. Over time, and with progression of disease, the MRL/lpr mice displayed a significant increase in IGF-I IR and a modest increase in IGFBP-2 IR within the outer cortical glomeruli, which was associated with a significant increase in glomerulosclerosis and glomerular cell proliferation and with a significant decrease in renal function. In conclusion, this overexpression of IGF-I and IGFBP-2 within the glomeruli of the MRL/lpr mouse kidney supports their potential role in the alterations in renal function and morphology that accompany lupus nephritis.
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Affiliation(s)
- J A Mohammed
- Department of Pediatrics and Child Health Research Institute, University of Western Ontario, London, Ontario, Canada
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9
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Abstract
In recent years, it has become clear that self-nonself discrimination by the immune system is driven not so much by the specificities of the antigen receptors themselves, but by ligand-receptor systems that sense the presence of foreign pathogens (toll-like receptors) and those that regulate the balance between cellular proliferation and programmed cell death (tumor necrosis factor [TNF] family ligands and receptors). Interestingly, these two receptor families share a number of common signaling pathways, mediated by the cytoplasmic proteins containing death domains and TRAF domains, which trigger the complementary processes of programmed cell death and inflammation. Both humans and mice with genetic defects in the TNF-receptor family member Fas accumulate abnormal lymphocytes and develop systemic autoimmunity. These findings highlighted the importance of this TNF-receptor family member in the homeostasis of the immune system. In particular, the Fas receptor has been shown to be important in immunoreceptor-mediated apoptosis of activated T and B lymphocytes. Six members of the TNF-receptor superfamily share a common signaling domain with Fas, termed the death domain, that directly links these receptors to the apoptotic machinery of the cell, and, collectively, these receptors have been designated as "death receptors."We are currently investigating a number of important unresolved issues in this field, including: (1). how susceptibility to apoptosis through death receptors is regulated, (2). how Fas and related death receptors function in the maintenance of self-tolerance and homeostasis in the major cell types of the immune system, and (3). recently described nonapoptotic lymphocyte activation signals that use components of death receptor signaling.
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Affiliation(s)
- Richard M Siegel
- Immunoregulation Section, Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institute of Health, Bethesda, MD 20892, USA.
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10
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Cohen PL, Caricchio R, Abraham V, Camenisch TD, Jennette JC, Roubey RAS, Earp HS, Matsushima G, Reap EA. Delayed apoptotic cell clearance and lupus-like autoimmunity in mice lacking the c-mer membrane tyrosine kinase. J Exp Med 2002; 196:135-40. [PMID: 12093878 PMCID: PMC2194017 DOI: 10.1084/jem.20012094] [Citation(s) in RCA: 457] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Mice lacking the membrane tyrosine kinase c-mer have been shown to have altered macro-phage cytokine production and defective phagocytosis of apoptotic cells despite normal phagocytosis of other particles. We show here that c-mer-deficient mice have impaired clearance of infused apoptotic cells and that they develop progressive lupus-like autoimmunity, with antibodies to chromatin, DNA, and IgG. The autoimmunity appears to be driven by endogenous antigens, with little polyclonal B cell activation. These mice should be an excellent model for studying the role of apoptotic debris as an immunogenic stimulus for systemic autoimmunity.
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Affiliation(s)
- Philip L Cohen
- Department of Medicine, Division of Rheumatology, University of Pennsylvania, and Philadelphia Veterans Affairs Medical Center, Philadelphia, PA 19104, USA.
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11
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Kretz-Rommel A, Rubin RL. Early cellular events in systemic autoimmunity driven by chromatin-reactive T cells. Cell Immunol 2001; 208:125-36. [PMID: 11333145 DOI: 10.1006/cimm.2001.1774] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In vivo exposure of the thymus of normal mice to procainamide-hydroxylamine, a lupus-inducing drug, causes development of chromatin-reactive T cells. Autoantibodies subsequently appear, but their origin and significance are unknown. The current studies were undertaken to determine the specificities of B cells that respond to chromatin-reactive T cells at the initiation of this autoimmune process. Three days after adoptive transfer of 6 x 10(6) chromatin-reactive T cells, B cells with the capacity to secrete IgM anti-chromatin antibodies were detected in 1/10(6) splenocytes, and these became 10- to 50-fold more numerous if either the donor T cells or the recipient had defective Fas due to the lpr allele. Five days later these mice developed IgG anti-chromatin-secreting B cells at a precursor frequency of 3-6 x 10(-5). B cells with dDNA-binding activity isolated from mice primed in vivo to a complex of methylated pigeon cytochrome c and dDNA could stimulate naive, cytochrome c-reactive T cells in vitro, demonstrating that B cells can internalize dDNA-bound proteins through their dDNA immunoblobulin receptor and can functionally present a T cell epitope. However, no capacity of chromatin for binding anti-dDNA antibodies was detected, and IgM dDNA-specific B cells did not expand when challenged with chromatin-reactive T cells in vivo. The rapid and robust expansion of anti-chromatin-secreting B cells indicates that the normal immune repertoire includes nontolerant autoreactive B cells that respond to strong T cell drive and are readily manifested if Fas-mediated activation-induced cell death is inhibited.
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Affiliation(s)
- A Kretz-Rommel
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, 92121, USA
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12
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Liang B, Kashgarian MJ, Sharpe AH, Mamula MJ. Autoantibody responses and pathology regulated by B7-1 and B7-2 costimulation in MRL/lpr lupus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:3436-43. [PMID: 10975864 DOI: 10.4049/jimmunol.165.6.3436] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The activation of T lymphocytes requires both Ag-mediated signaling through the TCR as well as costimulatory signals transmitted through B7-1 and/or B7-2 with CD28. The interference of B7-mediated costimulatory signals has been proposed as one immunotherapeutic intervention for the prevention autoimmune disease. This study has examined autoantibody responses and autoimmune pathology in a murine model of human systemic lupus erythematosus (SLE), the MRL-lpr/lpr mouse, genetically deficient in B7-1 or B7-2, or in mice treated with B7-1/B7-2 blocking Abs. In contrast to other studies of murine models of SLE, MRL-lpr/lpr mice treated with B7 blocking Abs exhibit strong anti-small nuclear ribonucleoprotein (snRNP) and anti-DNA autoantibody responses with some changes in isotype switching as compared with untreated animals. All MRL-lpr/lpr mice deficient in B7-1 or B7-2 produce anti-snRNP and anti-DNA titers with isotypes virtually identical with wild-type animals. However, the absence of B7-2 costimulation did interfere with the spontaneous activation and the accumulation of memory CD4+ or CD8+ T lymphocytes characteristic of wild-type MRL-lpr/lpr mice. IgG and C3 complement deposition was less pronounced in the kidneys of B7-2 deficient MRL-lpr/lpr mice, reflecting their lessor degree of glomerulonephritis. By comparison, B7-1-deficient MRL-lpr/lpr mice had more severe IgG and C3 deposits in glomeruli.
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Affiliation(s)
- B Liang
- Department of Internal Medicine, Section of Rheumatology, Yale University School of Medicine, New Haven, CT 06510, USA
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13
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Caricchio R, Cohen PL. Spontaneous and induced apoptosis in systemic lupus erythematosus: multiple assays fail to reveal consistent abnormalities. Cell Immunol 1999; 198:54-60. [PMID: 10612651 DOI: 10.1006/cimm.1999.1576] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The immunologic basis of systemic lupus erythematosus (SLE) is multifactorial and still elusive. Recent advances in the field of apoptosis have suggested new paradigms for the development of lupus autoimmunity. In the present studies we examined the possibility that individual populations of T and B cells are abnormally resistant to apoptosis or that they stand out in over- or underexpressing Fas. Fas was generally overexpressed in cells freshly isolated from SLE patients but the apoptotic response to FasL was normal. We did not find increased spontaneous ongoing apoptosis in SLE lymphocytes. Normal cleavage of PARP similarly implied that the final biochemical pathway of apoptosis is relatively intact in SLE. Finally we placed special emphasis on the response of SLE patient cells to UV irradiation, especially cells from photosensitive patients, and found no difference in Fas expression. In conclusion our results indicate that SLE patients do not suffer from a major apoptotic abnormality. The results also raise questions concerning the dynamic expression of Fas and the significance of ongoing apoptosis as a risk for autoimmune disease.
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Affiliation(s)
- R Caricchio
- Division of Rheumatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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14
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Sobel ES, Kakkanaiah VN, Schiffenbauer J, Reap EA, Cohen PL, Eisenberg RA. Novel Immunoregulatory B Cell Pathways Revealed by lpr-+ Mixed Chimeras. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.3.1497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
lpr, a murine mutation of the Fas apoptosis receptor, causes lymphadenopathy and autoantibody production, with lymphadenopathy primarily due to a population of CD4−CD8−B220+ T cells. Previous in vivo experiments, in which lpr and normal bone marrow cells were coinfused into lpr hosts, have demonstrated that only T cells of lpr origin accumulated abnormally and only B cells of lpr origin produced autoantibodies. Moreover, in these chimeras, B cells of normal origin were unable to respond to conventional, T cell-dependent exogenous Ag. To address the role of lpr B cells in regulation of lpr autoimmunity, we have prepared lpr-+ mixed chimeras and selectively eliminated lpr B cells using allele-specific, mAb treatment, thus allowing normal B cells to develop in an environment with lpr T cells. From these data, we arrived at four major conclusions: 1) Compared with control-treated chimeric mice, lpr B cell-depleted mice had greatly reduced total lymph node cell counts; 2) the T cells were derived equally from normal and lpr donors, and the percentage of lpr-derived CD4−CD8− T cells was greatly reduced; 3) despite the presence of the remaining lpr T cells, no autoantibodies were produced by the normal derived B cells; and 4) lpr T cells without lpr B cells were unable to prevent a normal B cell response to conventional Ag. These data demonstrate that B cells can play a critical and expansive regulatory role, not only for T cells, but for other B cells as well.
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Affiliation(s)
- Eric S. Sobel
- *Department of Medicine and Division of Rheumatology and Clinical Immunology, University of Florida, Gainesville, FL 32610; and
| | - Vellalore N. Kakkanaiah
- †Department of Medicine and Microbiology/Immunology, University of North Carolina, Chapel Hill, NC 27599
| | - Joel Schiffenbauer
- *Department of Medicine and Division of Rheumatology and Clinical Immunology, University of Florida, Gainesville, FL 32610; and
| | - Elizabeth A. Reap
- †Department of Medicine and Microbiology/Immunology, University of North Carolina, Chapel Hill, NC 27599
| | - Philip L. Cohen
- †Department of Medicine and Microbiology/Immunology, University of North Carolina, Chapel Hill, NC 27599
| | - Robert A. Eisenberg
- †Department of Medicine and Microbiology/Immunology, University of North Carolina, Chapel Hill, NC 27599
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15
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Abstract
We have previously isolated genes that encode Fas and Fas ligand, a receptor-ligand pair that mediates an apoptotic signal. We also have demonstrated that lpr and gld mice, well-known animal models of autoimmune disease are loss-of-function mutants of the Fas and Fas ligand genes, respectively. Patients with autoimmune lymphoproliferative disorders have been found to bear mutations of the Fas gene. These findings indicate that the Fas-Fas ligand system plays an important role in the maintenance of self-tolerance among both humans and mice. During T-cell development, mouse T cells initially express Fas in the thymus and maintain their expression thereafter. Peripheral B cells usually express Fas at much lower levels than do T cells, but various stimuli enhance Fas expression on B cells. In contrast, among the lymphocyte subsets, only activated T cells and natural killer cells express readily detectable levels of Fas ligand. Reactivation of previously activated T cells through T-cell receptors induces apoptosis. This phenomenon (activation-induced cell death) is mediated by means of the Fas-Fas ligand interaction. We recently discovered that peripheral naive T cells in mice are susceptible to Fas ligand but not to agonistic anti-Fas antibodies. To our surprise, engagement of T-cell receptors on naive T cells was shown to induce Fas ligand resistance. On the basis of these findings and other reports, we discuss how the breakdown of self-tolerance occurs as the result of defects in the Fas-Fas ligand system.
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Affiliation(s)
- T Suda
- Department of Molecular Biology, Osaka Bioscience Institute, Japan
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16
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Isenberg DA, Ravirajan CT, Rahman A, Kalsi J. The role of antibodies to DNA in systemic lupus erythematosus--a review and introduction to an international workshop on DNA antibodies held in London, May 1996. Lupus 1997; 6:290-304. [PMID: 9296771 DOI: 10.1177/096120339700600316] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
MESH Headings
- Animals
- Antibodies, Antinuclear/chemistry
- Antibodies, Antinuclear/classification
- Antibodies, Antinuclear/genetics
- Antibodies, Antinuclear/immunology
- Antibody Affinity
- Antibody Diversity
- Antibody Specificity
- Autoimmune Diseases/genetics
- Autoimmune Diseases/immunology
- Clone Cells/immunology
- Cloning, Molecular
- Crystallography, X-Ray
- DNA/immunology
- Disease Models, Animal
- Gene Expression Regulation
- Genes, Immunoglobulin
- Humans
- Immunoglobulin Variable Region/genetics
- Lupus Erythematosus, Systemic/genetics
- Lupus Erythematosus, Systemic/immunology
- Lupus Nephritis/immunology
- Magnetic Resonance Spectroscopy
- Mice
- Mice, Inbred MRL lpr
- Mice, Inbred NZB
- Mutagenesis, Site-Directed
- Mutation
- Transfection
- fas Receptor/physiology
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Affiliation(s)
- D A Isenberg
- Department of Medicine, University College, London, UK
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17
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Elkon KB, Marshak-Rothstein A. B cells in systemic autoimmune disease: recent insights from Fas-deficient mice and men. Curr Opin Immunol 1996; 8:852-9. [PMID: 8994866 DOI: 10.1016/s0952-7915(96)80015-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In mice functionally deficient for either Fas or Fas ligand expression, the failure of Fas-ligand-expressing cytotoxic T cells to eliminate autoreactive B cells can result in excessive autoantibody production. Recent in vitro studies have shown that B cells activated by CD40 ligand become extremely sensitive to Fas-mediated apoptosis while IL-4 and/or surface IgM receptor engagement protects B cells from Fas ligand cytolysis. Potential in vivo sites for Fas ligand regulation of self-reactive B cells have been suggested and implications for human disease have been investigated.
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Affiliation(s)
- K B Elkon
- Hospital for Special Surgery, Cornell University Medical Center, New York 10021, USA.
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Smith KG, Nossal GJ, Tarlinton DM. FAS is highly expressed in the germinal center but is not required for regulation of the B-cell response to antigen. Proc Natl Acad Sci U S A 1995; 92:11628-32. [PMID: 8524817 PMCID: PMC40455 DOI: 10.1073/pnas.92.25.11628] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In establishing the memory B-cell population and maintaining self-tolerance during an immune response, apoptosis mediates the removal of early, low-affinity antibody-forming cells, unselected germinal center (GC) cells, and, potentially, self-reactive B cells. To address the role of the apoptosis-signaling cell surface molecule FAS in the B-cell response to antigen, we have examined the T-cell-dependent B-cell response to the carrier-conjugated hapten (4-hydroxy-3-nitrophenyl)acetyl (NP) in lpr mice in which the fas gene is mutated. High levels of FAS were expressed on normal GC B cells but the absence of FAS did not perturb the progressive decline in numbers of either GC B cells or extrafollicular antibody-forming cells. Furthermore, the rate of formation and eventual size of the NP-specific memory B-cell population in lpr mice were normal. The accumulation of cells with affinity-enhancing mutations and the appearance of high-affinity anti-NP IgG1 antibody in the serum were also normal in lpr mice. Thus, although high levels of FAS are expressed on GC B cells, FAS is not required for GC selection or for regulation of the major antigen-specific B-cell compartments. The results suggest that the size and composition of B-cell compartments in the humoral immune response are regulated by mechanisms that do not require FAS.
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Affiliation(s)
- K G Smith
- Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Victoria, Australia
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