scholarly journals Complement C4 Inhibits Systemic Autoimmunity through a Mechanism Independent of Complement Receptors Cr1 and Cr2

2000 ◽  
Vol 192 (9) ◽  
pp. 1339-1352 ◽  
Author(s):  
Zhibin Chen ◽  
Sergei B. Koralov ◽  
Garnett Kelsoe
Keyword(s):  
B Cells ◽  
Lupus Erythematosus ◽  
Complement Receptors ◽  
T And B Cells ◽  
Autoantibody Production ◽  
Systemic Autoimmunity ◽  
C4 Deficiency ◽  
Humoral Responses ◽  
The Complement System ◽  
Normal Controls

The complement system enhances antibody responses to T-dependent antigens, but paradoxically, deficiencies in C1 and C4 are strongly linked to autoantibody production in humans. In mice, disruption of the C1qa gene also results in spontaneous autoimmunity. Moreover, deficiencies in C4 or complement receptors 1 and 2 (CR1/CR2) lead to reduced selection against autoreactive B cells and impaired humoral responses. These observations suggest that C1 and C4 act through CR1/CR2 to enhance humoral immunity and somehow suppress autoimmunity. Here we report high titers of spontaneous antinuclear antibody (ANA) in C4−/− mice. This systemic lupus erythematosus–like autoimmunity is highly penetrant; by 10 mo of age, all C4−/− females and most males produced ANA. In contrast, titers and frequencies of ANA in Cr2−/− mice, which are deficient in CR1 and CR2, never rose significantly above those in normal controls. Glomerular deposition of immune complexes (ICs), glomerulonephritis, and splenomegaly were observed in C4−/− but not Cr2−/− mice. C4−/−, but not Cr2−/−, mice accumulate activated T and B cells. Clearance of circulating ICs is impaired in preautoimmune C4−/−, but not Cr2−/−, mice. C4 deficiency causes spontaneous, lupus-like autoimmunity through a mechanism that is independent of CR1/CR2.

scholarly journals An intrinsic B cell defect is required for the production of autoantibodies in the lpr model of murine systemic autoimmunity.

1991 ◽  
Vol 173 (6) ◽  
pp. 1441-1449 ◽  
Author(s):  
E S Sobel ◽  
T Katagiri ◽  
K Katagiri ◽  
S C Morris ◽  
P L Cohen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Immunofluorescence Assay ◽  
Total Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Phenotype ◽  
Autoantibody Production ◽  
Systemic Autoimmunity

Mice homozygous for the gene lpr develop marked lymphadenopathy and a spectrum of autoantibodies closely resembling that of human systemic lupus erythematosus. The unusual T cell phenotype of the expanded lymphocyte population and the T-dependence of several antibodies in this strain have suggested that primary T cell abnormalities underlie the autoimmune syndrome. Using double chimeras, we now show that expression of the lpr gene in B cells is absolutely necessary for autoantibody production. Combinations of anti-Thy 1.2 + C' treated bone marrow from congenic strains of C57BL/6 mice, differing only at the immunoglobulin heavy chain (Igh) and lpr loci, were transferred into lethally irradiated B6/lpr mice. Double chimerism was documented by allotype-specific surface IgD and IgM immunofluorescence assay of peripheral blood and by allotype-specific enzyme-linked immunosorbent assay for total IgM in serum. Despite the presence of both +/+ and lpr B cells, IgM and IgG2a anti-chromatin as well as IgM anti-IgG were entirely the products of lpr B cells. Total serum IgG2a and IgG1 were also dominated by the lpr phenotype but not to the same extent. A similar experiment using B6/lpr-Igha recipients confirmed these findings. Additional experiments in which B6/lpr recipients were infused with ratios of donor bone marrow favoring B6.C20 +/+ over B6/lpr showed that even though +/+ B cells were overrepresented, autoantibodies were only of the lpr allotype. In addition, in the presence of lpr B cells, normal B cells showed little response to an exogenous, T cell-dependent antigen. The data thus indicate that lpr B cells manifest an intrinsic abnormality which is essential for autoantibody production in the lpr model.

scholarly journals Deep Phenotyping of CD11c+ B Cells in Systemic Autoimmunity and Controls

2021 ◽  
Vol 12 ◽  
Author(s):  
Hector Rincon-Arevalo ◽  
Annika Wiedemann ◽  
Ana-Luisa Stefanski ◽  
Marie Lettau ◽  
Franziska Szelinski ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Activation ◽  
B Cell Activation ◽  
Membrane Expression ◽  
Ki 67 ◽  
Inflammatory Conditions ◽  
Systemic Autoimmunity ◽  
Enhanced Expression

Circulating CD11c+ B cells are a key phenomenon in certain types of autoimmunity but have also been described in the context of regular immune responses (i.e., infections, vaccination). Using mass cytometry to profile 46 different markers on individual immune cells, we systematically initially confirmed the presence of increased CD11c+ B cells in the blood of systemic lupus erythematosus (SLE) patients. Notably, significant differences in the expression of CD21, CD27, and CD38 became apparent between CD11c− and CD11c+ B cells. We observed direct correlation of the frequency of CD21−CD27− B cells and CD21−CD38− B cells with CD11c+ B cells, which were most pronounced in SLE compared to primary Sjögren's syndrome patients (pSS) and healthy donors (HD). Thus, CD11c+ B cells resided mainly within memory subsets and were enriched in CD27−IgD−, CD21−CD27−, and CD21−CD38− B cell phenotypes. CD11c+ B cells from all donor groups (SLE, pSS, and HD) showed enhanced CD69, Ki-67, CD45RO, CD45RA, and CD19 expression, whereas the membrane expression of CXCR5 and CD21 were diminished. Notably, SLE CD11c+ B cells showed enhanced expression of the checkpoint molecules CD86, PD1, PDL1, CD137, VISTA, and CTLA-4 compared to HD. The substantial increase of CD11c+ B cells with a CD21− phenotype co-expressing distinct activation and checkpoint markers, points to a quantitative increased alternate (extrafollicular) B cell activation route possibly related to abnormal immune regulation as seen under the striking inflammatory conditions of SLE which shows a characteristic PD-1/PD-L1 upregulation.

scholarly journals Effect of Human Mesenchymal Stem Cells on Xenogeneic T and B Cells Isolated from Lupus-Prone MRL.Faslpr Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Hong Kyung Lee ◽  
Eun Young Kim ◽  
Hyung Sook Kim ◽  
Eun Jae Park ◽  
Hye Jin Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
Mesenchymal Stem Cells ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Human Mesenchymal Stem Cells ◽  
Preclinical Studies ◽  
Dependent Manner ◽  
T And B Cells

Systemic lupus erythematosus (SLE) is an autoimmune disease, which is characterized by hyperactivation of T and B cells. Human mesenchymal stem cells (hMSCs) ameliorate the progression of SLE in preclinical studies using lupus-prone MRL.Faslpr mice. However, whether hMSCs inhibit the functions of xenogeneic mouse T and B cells is not clear. To address this issue, we examined the in vitro effects of hMSCs on T and B cells isolated from MRL.Faslpr mice. Naïve hMSCs inhibited the functions of T cells but not B cells. hMSCs preconditioned with IFN-γ (i) inhibited the proliferation of and IgM production by B cells, (ii) attracted B cells for cell–cell interactions in a CXCL10-dependent manner, and (iii) inhibited B cells by producing indoleamine 2,3-dioxygenase. In summary, our data demonstrate that hMSCs exert therapeutic activity in mice in three steps: first, naïve hMSCs inhibit the functions of T cells, hMSCs are then activated by IFN-γ, and finally, they inhibit B cells.

scholarly journals Multiple Functions of B Cells in the Pathogenesis of Systemic Lupus Erythematosus

2019 ◽  
Vol 20 (23) ◽  
pp. 6021 ◽  
Author(s):  
Kongyang Ma ◽  
Wenhan Du ◽  
Xiaohui Wang ◽  
Shiwen Yuan ◽  
Xiaoyan Cai ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Therapeutic Interventions ◽  
Systemic Lupus ◽  
Autoantibody Production ◽  
Regulatory B Cell ◽  
Functional Features ◽  
B Cell Subsets

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by excessive autoantibody production and multi-organ involvement. Although the etiology of SLE still remains unclear, recent studies have characterized several pathogenic B cell subsets and regulatory B cell subsets involved in the pathogenesis of SLE. Among pathogenic B cell subsets, age-associated B cells (ABCs) are a newly identified subset of autoreactive B cells with T-bet-dependent transcriptional programs and unique functional features in SLE. Accumulation of T-bet+ CD11c+ ABCs has been observed in SLE patients and lupus mouse models. In addition, innate-like B cells with the autoreactive B cell receptor (BCR) expression and long-lived plasma cells with persistent autoantibody production contribute to the development of SLE. Moreover, several regulatory B cell subsets with immune suppressive functions have been identified, while the impaired inhibitory effects of regulatory B cells have been indicated in SLE. Thus, further elucidation on the functional features of B cell subsets will provide new insights in understanding lupus pathogenesis and lead to novel therapeutic interventions in the treatment of SLE.

scholarly journals MicroRNA in Sjögren’s Syndrome: Their Potential Roles in Pathogenesis and Diagnosis

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
M. Reale ◽  
C. D’Angelo ◽  
E. Costantini ◽  
M. Laus ◽  
A. Moretti ◽  
...  
Keyword(s):  
B Cells ◽  
Sjögren’S Syndrome ◽  
Sjögren's Syndrome ◽  
Lymphocytic Infiltration ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Exocrine Glands ◽  
Autoantibody Production ◽  
Systemic Autoimmunity ◽  
Sjögren‘S Syndrome

Sjögren’s syndrome (SS) or sicca syndrome was described by Swedish ophthalmologist Sjögren in the year 1933 for the first time. The etiology of the SS is multifunctional and includes a combination of genetic predisposition and environmental as well as epigenetic factors. It is an autoimmune disease characterized by features of systemic autoimmunity, dysfunction, and inflammation in the exocrine glands (mainly salivary and lacrimal glands) and lymphocytic infiltration of exocrine glands. In fact, the involvement of lacrimal and salivary glands results in the typical features of dry eye and salivary dysfunction (xerostomia). Only in one-third of the patients also present systemic extraglandular manifestations. T cells were originally considered to play the initiating role in the autoimmune process, while B cells were restricted to autoantibody production. In recent years, it is understood that the roles of B cells are multiple. Moreover, autoantibodies and blood B cell analysis are major contributors to a clinical diagnosis of Sjögren’s syndrome. Recently, there has been rising interest in microRNA implication in autoimmunity. Unfortunately, to date, there are only a few studies that have investigated their participation in SS etiopathogenesis. The purpose of this work is to gather the data present in the literature to clarify this complex topic.

scholarly journals Dual regulation of IRF4 function in T and B cells is required for the coordination of T–B cell interactions and the prevention of autoimmunity

2012 ◽  
Vol 209 (3) ◽  
pp. 581-596 ◽  
Author(s):  
Partha S. Biswas ◽  
Sanjay Gupta ◽  
Roslynn A. Stirzaker ◽  
Varsha Kumar ◽  
Rolf Jessberger ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
T Helper Cells ◽  
Regulatory Protein ◽  
Cell Interactions ◽  
T Helper ◽  
T And B Cells ◽  
Helper Cells

Effective humoral responses to protein antigens require the precise execution of carefully timed differentiation programs in both T and B cell compartments. Disturbances in this process underlie the pathogenesis of many autoimmune disorders, including systemic lupus erythematosus (SLE). Interferon regulatory factor 4 (IRF4) is induced upon the activation of T and B cells and serves critical functions. In CD4+ T helper cells, IRF4 plays an essential role in the regulation of IL-21 production, whereas in B cells it controls class switch recombination and plasma cell differentiation. IRF4 function in T helper cells can be modulated by its interaction with regulatory protein DEF6, a molecule that shares a high degree of homology with only one other protein, SWAP-70. Here, we demonstrate that on a C57BL/6 background the absence of both DEF6 and SWAP-70 leads to the development of a lupus-like disease in female mice, marked by simultaneous deregulation of CD4+ T cell IL-21 production and increased IL-21 B cell responsiveness. We furthermore show that DEF6 and SWAP-70 are differentially used at distinct stages of B cell differentiation to selectively control the ability of IRF4 to regulate IL-21 responsiveness in a stage-specific manner. Collectively, these data provide novel insights into the mechanisms that normally couple and coordinately regulate T and B cell responses to ensure tight control of productive T–B cell interactions.

scholarly journals Nonbilayer Phospholipid Arrangements Are Toll-Like Receptor-2/6 and TLR-4 Agonists and Trigger Inflammation in a Mouse Model Resembling Human Lupus

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Carlos Wong-Baeza ◽  
Alonso Tescucano ◽  
Horacio Astudillo ◽  
Albany Reséndiz ◽  
Carla Landa ◽  
...  
Keyword(s):  
B Cells ◽  
Lupus Erythematosus ◽  
Innate Immune ◽  
Toll Like Receptor ◽  
Autoantibody Production ◽  
Immune System Activation ◽  
Expression Of Genes ◽  
Nuclear Antigens ◽  
Proinflammatory Gene ◽  
Toll Like Receptor 2

Systemic lupus erythematosus is characterized by dysregulated activation of T and B cells and autoantibodies to nuclear antigens and, in some cases, lipid antigens. Liposomes with nonbilayer phospholipid arrangements induce a disease resembling human lupus in mice, including IgM and IgG antibodies against nonbilayer phospholipid arrangements. As the effect of these liposomes on the innate immune response is unknown and innate immune system activation is necessary for efficient antibody formation, we evaluated the effect of these liposomes on Toll-like receptor (TLR) signaling, cytokine production, proinflammatory gene expression, and T, NKT, dendritic, and B cells. Liposomes induce TLR-4- and, to a lesser extent, TLR-2/TLR-6-dependent signaling in TLR-expressing human embryonic kidney (HEK) cells and bone marrow-derived macrophages. Mice with the lupus-like disease had increased serum concentrations of proinflammatory cytokines, C3a and C5a; they also had more TLR-4-expressing splenocytes, a higher expression of genes associated with TRIF-dependent TLR-4-signaling and complement activation, and a lower expression of apoptosis-related genes, compared to healthy mice. The percentage of NKT and the percentage and activation of dendritic and B2 cells were also increased. Thus, TLR-4 and TLR-2/TLR-6 activation by nonbilayer phospholipid arrangements triggers an inflammatory response that could contribute to autoantibody production and the generation of a lupus-like disease in mice.

scholarly journals Deficiency of the Cyclin Kinase Inhibitor p21(WAF-1/CIP-1) Promotes Apoptosis of Activated/Memory T Cells and Inhibits Spontaneous Systemic Autoimmunity

2004 ◽  
Vol 199 (4) ◽  
pp. 547-557 ◽  
Author(s):  
Brian R. Lawson ◽  
Roberto Baccala ◽  
Jianxun Song ◽  
Michael Croft ◽  
Dwight H. Kono ◽  
...  
Keyword(s):  
Cell Cycle ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Systemic Autoimmunity ◽  
Novel Approach ◽  
Proliferation And Apoptosis ◽  
Cell Cycle Pathway

A characteristic feature of systemic lupus erythematosus is the accumulation of activated/memory T and B cells. These G0/G1-arrested cells express high levels of cyclin-dependent kinase inhibitors such as p21, are resistant to proliferation and apoptosis, and produce large amounts of proinflammatory cytokines. Herein, we show that ablation of p21 in lupus-prone mice allows these cells to reenter the cell cycle and undergo apoptosis, leading to autoimmune disease reduction. Absence of p21 resulted in enhanced Fas/FasL-mediated activation-induced T cell death, increased activation of procaspases 8 and 3, and loss of mitochondrial transmembrane potential. Increased apoptosis was also associated with p53 up-regulation and a modest shift in the ratio of Bax/Bcl-2 toward the proapoptotic Bax. Proliferation and apoptosis of B cells were also increased in p21−/− lupus mice. Thus, modulation of the cell cycle pathway may be a novel approach to reduce apoptosis-resistant pathogenic lymphocytes and to ameliorate systemic autoimmunity.

scholarly journals The Pathology of T Cells in Systemic Lupus Erythematosus

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Anselm Mak ◽  
Nien Yee Kow
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Clinical Trials ◽  
T Cells ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Calcineurin Inhibitors ◽  
Cell Receptor ◽  
Systemic Lupus ◽  
Autoantibody Production ◽  
Lupus Glomerulonephritis

Systemic lupus erythematosus (SLE) is characterized by the production of a wide array of autoantibodies. Thus, the condition was traditionally classified as a “B-cell disease”. Compelling evidence has however shown that without the assistance of the helper T lymphocytes, it is indeed difficult for the “helpless” B cells to become functional enough to trigger SLE-related inflammation. T cells have been recognized to be crucial in the pathogenicity of SLE through their capabilities to communicate with and offer enormous help to B cells for driving autoantibody production. Recently, a number of phenotypic and functional alterations which increase the propensity to trigger lupus-related inflammation have been identified in lupus T cells. Here, potential mechanisms involving alterations in T-cell receptor expressions, postreceptor downstream signalling, epigenetics, and oxidative stress which favour activation of lupus T cells will be discussed. Additionally, how regulatory CD4+, CD8+, andγδT cells tune down lupus-related inflammation will be highlighted. Lastly, while currently available outcomes of clinical trials evaluating therapeutic agents which manipulate the T cells such as calcineurin inhibitors indicate that they are at least as efficacious and safe as conventional immunosuppressants in treating lupus glomerulonephritis, larger clinical trials are undoubtedly required to validate these as-yet favourable findings.

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