scholarly journals Regulation of Anti–double-stranded DNA B Cells in Nonautoimmune Mice: Localization to the T–B Interface of the Splenic Follicle

1997 ◽  
Vol 186 (8) ◽  
pp. 1257-1267 ◽  
Author(s):  
Laura Mandik-Nayak ◽  
Anh Bui ◽  
Hooman Noorchashm ◽  
Ashlyn Eaton ◽  
Jan Erikson
Keyword(s):  
B Cells ◽  
Lupus Erythematosus ◽  
Turnover Rate ◽  
Cell Repertoire ◽  
Developmental Arrest ◽  
Double Stranded Dna ◽  
B Cell Repertoire ◽  
Dna Antibodies ◽  
Unique Surface

Systemic lupus erythematosus (SLE) and the MRL-lpr/lpr murine model for SLE are characterized by the presence of serum anti–double-stranded (ds)DNA antibodies (Abs), whereas nonautoimmune individuals have negligible levels of these Abs. To increase the frequency of anti-DNA B cells and identify the mechanisms involved in their regulation in nonautoimmune mice, we have used Ig transgenes (tgs). In the present study, we used the VH3H9 heavy (H) chain tg which expresses an H chain that was repeatedly isolated from anti-dsDNA Abs from MRL-lpr/lpr mice. Because the VH3H9 H chain can pair with endogenous L chains to generate anti–single-stranded DNA, anti-dsDNA, and non-DNA B cells, this allowed us to study the regulation of anti-dsDNA B cells in the context of a diverse B cell repertoire. We have identified anti-dsDNA B cells that are located at the T–B interface in the splenic follicle where they have an increased in vivo turnover rate. These anti-dsDNA B cells exhibit a unique surface phenotype suggesting developmental arrest due to antigen exposure.

scholarly journals MRL-lpr/lpr Mice Exhibit a Defect in Maintaining Developmental Arrest and Follicular Exclusion of Anti–double-stranded DNA B Cells

1999 ◽  
Vol 189 (11) ◽  
pp. 1799-1814 ◽  
Author(s):  
Laura Mandik-Nayak ◽  
Su-jean Seo ◽  
Caroline Sokol ◽  
Kathryn M. Potts ◽  
Anh Bui ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Genetic Background ◽  
Systemic Lupus ◽  
Autoreactive B Cells ◽  
Developmental Arrest ◽  
Double Stranded Dna ◽  
Dna Antibodies ◽  
Cell Defect

A hallmark of systemic lupus erythematosus and the MRL murine model for lupus is the presence of anti–double-stranded (ds)DNA antibodies (Abs). To identify the steps leading to the production of these Abs in autoimmune mice, we have compared the phenotype and localization of anti-dsDNA B cells in autoimmune (MRL+/+ and lpr/lpr) mice with that in nonautoimmune (BALB/c) mice. Anti-dsDNA B cells are actively regulated in BALB/c mice as indicated by their developmental arrest and accumulation at the T–B interface of the splenic follicle. In the MRL genetic background, anti-dsDNA B cells are no longer developmentally arrested, suggesting an intrinsic B cell defect conferred by MRL background genes. With intact Fas, they continue to exhibit follicular exclusion; however, in the presence of the lpr/lpr mutation, anti-dsDNA B cells are now present in the follicle. Coincident with the altered localization of anti-dsDNA B cells is a follicular infiltration of CD4 T cells. Together, these data suggest that MRL mice are defective in maintaining the developmental arrest of autoreactive B cells and indicate a role for Fas in restricting entry into the follicle.

In vivo suppression of perinatal multispecific B cells results in a distortion of the adult B cell repertoire

1986 ◽  
Vol 16 (9) ◽  
pp. 1159-1165 ◽  
Author(s):  
Meenal Vakil ◽  
Helmut Sauter ◽  
Christopher Paige ◽  
John F. Kearney
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Repertoire ◽  
B Cell Repertoire

scholarly journals A role for gut-associated lymphoid tissue in shaping the human B cell repertoire

2013 ◽  
Vol 210 (9) ◽  
pp. 1665-1674 ◽  
Author(s):  
Anna Vossenkämper ◽  
Paul A. Blair ◽  
Niloufar Safinia ◽  
Louise D. Fraser ◽  
Lisa Das ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Lymphoid Tissue ◽  
Plasma Cells ◽  
Cell Subset ◽  
Cell Repertoire ◽  
Human B Cells ◽  
B Cell Repertoire ◽  
Immature B Cells

We have tracked the fate of immature human B cells at a critical stage in their development when the mature B cell repertoire is shaped. We show that a major subset of bone marrow emigrant immature human B cells, the transitional 2 (T2) B cells, homes to gut-associated lymphoid tissue (GALT) and that most T2 B cells isolated from human GALT are activated. Activation in GALT is a previously unknown potential fate for immature human B cells. The process of maturation from immature transitional B cell through to mature naive B cell includes the removal of autoreactive cells from the developing repertoire, a process which is known to fail in systemic lupus erythematosus (SLE). We observe that immature B cells in SLE are poorly equipped to access the gut and that gut immune compartments are depleted in SLE. Thus, activation of immature B cells in GALT may function as a checkpoint that protects against autoimmunity. In healthy individuals, this pathway may be involved in generating the vast population of IgA plasma cells and also the enigmatic marginal zone B cell subset that is poorly understood in humans.

scholarly journals Somatic Mutation and Light Chain Rearrangement Generate Autoimmunity in Anti–Single-Stranded DNA Transgenic Mrl/lpr Mice

1999 ◽  
Vol 190 (5) ◽  
pp. 691-704 ◽  
Author(s):  
Frederic Brard ◽  
Michele Shannon ◽  
Eline Luning Prak ◽  
Samuel Litwin ◽  
Martin Weigert
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
Somatic Mutation ◽  
Light Chain ◽  
Lupus Erythematosus ◽  
Direct Evidence ◽  
Cell Nuclei ◽  
Systemic Lupus ◽  
Double Stranded Dna

Antibodies to single-stranded (ss)DNA are expressed in patients with systemic lupus erythematosus and in lupus-prone mouse models such as the MRL/Mp-lpr/lpr (MRL/lpr) strain. In nonautoimmune mice, B cells bearing immunoglobulin site-directed transgenes (sd-tgs) that code for anti-ssDNA are functionally silenced. In MRL/lpr autoimmune mice, the same sd-tgs are expressed in peripheral B cells and these autoantibodies gain the ability to bind other autoantigens such as double-stranded DNA and cell nuclei. These new specificities arise by somatic mutation of the anti-ssDNA sd-tgs and by secondary light chain rearrangement. Thus, B cells that in normal mice are anergic can be activated in MRL/lpr mice, which can lead to the generation of pathologic autoantibodies. In this paper, we provide the first direct evidence for peripheral rearrangement in vivo.

scholarly journals Efficient reprogramming of the heavy-chain CDR3 regions of a human antibody repertoire

2021 ◽  
Author(s):  
Tiangling Ou ◽  
Wenhui He ◽  
Brian D Quinlan ◽  
Yan Guo ◽  
Pabalu Karunadharma ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Heavy Chain ◽  
Human Antibody ◽  
Cell Repertoire ◽  
Viral Control ◽  
Human B Cells ◽  
B Cell Repertoire ◽  
Hiv 1

B cells have been engineered ex vivo to express an HIV-1 broadly neutralizing antibody (bNAb). B-cell reprograming may be scientifically and therapeutically useful, but current approaches limit B-cell repertoire diversity and disrupt the organization of the heavy-chain locus. A more diverse and physiologic B-cell repertoire targeting a key HIV-1 epitope could facilitate evaluation of vaccines designed to elicit bNAbs, help identity more potent and bioavailable bNAb variants, or directly enhance viral control in vivo. Here we address the challenges of generating such a repertoire by replacing the heavy-chain CDR3 (HCDR3) regions of primary human B cells. To do so, we identified and utilized an uncharacterized Cas12a ortholog that recognizes PAM motifs present in human and murine JH genes. We also optimized the design of 200 nucleotide homology-directed repair templates (HDRT) by minimizing the required 3'-5' resection of the HDRT-complementary strand. Using these techniques, we edited primary human B cells to express a hemagglutinin epitope tag and the HCDR3 regions of the bNAbs PG9 and CH01. Those edited with bNAb HCDR3 efficiently bound trimeric HIV-1 antigens, implying they could affinity mature in vivo in response to the same antigens. This approach generates diverse B-cell repertoires recognizing a key HIV-1 neutralizing epitope.

scholarly journals Light Chain Usage in Anti–double-stranded DNA B Cell Subsets: Role in Cell Fate Determination

1997 ◽  
Vol 185 (7) ◽  
pp. 1317-1326 ◽  
Author(s):  
Linda Spatz ◽  
Vladimir Saenko ◽  
Andrey Iliev ◽  
Lori Jones ◽  
Larisa Geskin ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Fate ◽  
Light Chain ◽  
Lupus Erythematosus ◽  
High Avidity ◽  
Double Stranded Dna ◽  
Dna Antibodies ◽  
B Cell Subsets ◽  
Self Antigen

Two major mechanisms for the regulation of autoreactive B cells that arise in the bone marrow are functional silencing (anergy) and deletion. Studies to date suggest that low avidity interactions between B cells and autoantigen lead to B cell silencing, whereas high avidity interactions lead to deletion. Anti–double stranded (ds) DNA antibodies represent a pathogenic autospecificity in Systemic Lupus Erythematosus (SLE). An understanding of their regulation is critical to an understanding of SLE. We now demonstrate in a transgenic model in which mice express the heavy chain of a potentially pathogenic anti-DNA antibody that antibody affinity for dsDNA does not alone determine the fate of anti-dsDNA B cells. B cells making antibodies with similar affinities for dsDNA are regulated differently, depending on light chain usage. A major implication of this observation is that dsDNA may not be the self antigen responsible for cell fate determinations of anti-dsDNA B cells. Light chain usage may determine antigenic crossreactivity, and cross-reactive antigens may regulate B cells that also bind dsDNA.

scholarly journals B Cell Abnormalities in Systemic Lupus Erythematosus and Lupus Nephritis—Role in Pathogenesis and Effect of Immunosuppressive Treatments

2019 ◽  
Vol 20 (24) ◽  
pp. 6231 ◽  
Author(s):  
Desmond Y. H. Yap ◽  
Tak Mao Chan
Keyword(s):  
Systemic Lupus Erythematosus ◽  
T Cell ◽  
B Cells ◽  
Lupus Nephritis ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Interaction ◽  
Systemic Lupus ◽  
Cell Repertoire ◽  
B Cell Repertoire

Abnormalities in B cells play pivotal roles in the pathogenesis of systemic lupus erythematosus (SLE) and lupus nephritis (LN). Breach in central and peripheral tolerance mechanisms generates autoreactive B cells which contribute to the pathogenesis of SLE and LN. Dysregulation of B cell transcription factors, cytokines and B cell–T cell interaction can result in aberrant B cell maturation and autoantibody production. These immunological abnormalities also lead to perturbations in circulating and infiltrating B cells in SLE and LN patients. Conventional and novel immunosuppressive medications confer differential effects on B cells which have important clinical implications. While cyclophosphamide and mycophenolate mofetil (MMF) showed comparable clinical efficacy in active LN, MMF induction was associated with earlier reduction in circulating plasmablasts and plasma cells. Accumulating evidence suggests that MMF maintenance is associated with lower risk of disease relapse than azathioprine, which may be explained by its more potent and selective suppression of B cell proliferation. Novel therapeutic approaches targeting the B cell repertoire include B cell depletion with monoclonal antibodies binding to cell surface markers, inhibition of B cell cytokines, and modulation of costimulatory signals in B cell–T cell interaction. These biologics, despite showing improvements in serological parameters and proteinuria, did not achieve primary endpoints when used as add-on therapy to standard treatments in active LN patients. Other emerging treatments such as calcineurin inhibitors, mammalian target of rapamycin inhibitors and proteasome inhibitors also show distinct inhibitory effects on the B cell repertoire. Advancement in the knowledge on B cell biology has fueled the development of new therapeutic strategies in SLE and LN. Modification in background treatments, study endpoints and selective recruitment of subjects showing aberrant B cells or its signaling pathways when designing future clinical trials may better elucidate the roles of these novel therapies for SLE and LN patients.

From B-Cell Tolerance to Autoimmunity

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. SCI-1-SCI-1
Author(s):  
Ann Marshak-Rothstein
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Biology ◽  
Cell Activation ◽  
B Cell Activation ◽  
Cell Repertoire ◽  
Autoreactive B Cells

Abstract Despite numerous mechanisms that exist to purge the B-cell repertoire of potentially dangerous autoreactive cells, it is now clear that numerous cells with the capability of binding self determinants survive negative selection and persist peripherally as anergic or ignorant cells. Exactly how these B cells are normally constrained, and then aberrantly activated in the context of autoimmunity, are two major questions in B-cell biology. A better understanding of the mechanisms involved in these processes could provide important insights to the regulation of alloreactivity. One clue to our understanding of autoimmunity comes from the nature of the autoantigens commonly targeted in systemic autoimmune diseases. Autoantigens often consist of macromolecular complexes that incorporate self-nucleic acids, and numerous in vitro studies have now shown that many of these canonical autoantigens are essentially potent endogenous autoadjuvants. Mice expressing a low affinity BCR specific for autologous IgG2a can be potently activated by DNA or RNA-associated immune complexes through a mechanism dependent on both the BCR and either TLR9 or TLR7, and serve as a useful prototype for autoreactive B cells in general. A number of groups have now tested this BCR/TLR paradigm in vivo. As expected, Tlr9-/- autoimmune-prone mice fail to produce autoantibodies directed against chromatin, while Tlr7-/- mice fail to produce autoantibodies directed against numerous RNA-associated proteins. However, the Tlr9-/- mice develop accelerated clinical disease, while the Tlr7-/- mice exhibit remarkably prolonged survival. We have now shown that BCR/TLR9 and BCR/TLR7 induce inherently different functional outcomes in B cells. Quite remarkably, both in vitro and in vivo, BCR/TLR7-dependent activation of autoreactive B cells leads to a more prolonged response and increased numbers of antibody producing cells. This response can be defined by a unique gene-expression profile and associated with proteins known to promote plasmablast differentiation. By contrast, BCR/TLR9 activation appears to initially limit autoreactive B-cell expansion; although in the context of systemic autoimmunity TLR9 is required for the production of DNA-reactive autoantibodies. Together these data indicate that the outcome BCR/TLR9 engagement of autoreactive B cells is highly dependent on environmental cues, and suggest that BCR/TLR7 B-cell activation is a key factor in the initiation of systemic lupus erythematosus and other systemic disorders. Disclosures: Marshak-Rothstein: Idera Pharmaceuticals: Consultancy; Abbvie: Consultancy; Genentech: Honoraria.

scholarly journals AB0146 DRUG DEPENDENT ALTERATIONS IN B-CELL REPERTOIRE IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITH LOW DISEASE ACTIVITY

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1373.2-1373
Author(s):  
S. Zenz ◽  
B. Dreo ◽  
B. Prietl ◽  
S. Kofler ◽  
H. Sourij ◽  
...  
Keyword(s):  
B Cells ◽  
Disease Activity ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Repertoire ◽  
Low Disease Activity ◽  
B Cell Repertoire ◽  
Drug Dependent ◽  
B Cell Subsets

Background:B-cells play a major role in the pathogenesis and perpetuation of the immune response in systemic lupus erythematosus (SLE). So far, B-cell subtypes have been studied well, but the precise mechanisms of the B-cell alterations during disease activity and during remission, depending on different medication, are still unclear.Objectives:The aim of our study was to investigate the drug dependent alterations in the B-cell repertoire of SLE patients with low disease activity (SLEDAI – 2K ≤4).Methods:Peripheral blood samples from 39 patients suffering from SLE (mean±SD; age 43±13 years, 87.2% females, disease duration 11.1±7 years) were drawn over 2 years. All SLE patients were in remission or low disease activity (median±SE, SLEDAI of 2.0±1.5). B-cells were characterized using CD19, CD20, CD5, CD27 antibodies and were grouped in naïve (IgD+27-), non-switched memory (IgD+, CD27+), memory (IgD-,CD27+), B1 (CD5+27-) and MBL-like (CD5++) B-cells. A quantitative flow cytometric bead-based assay (QuantiBRITE PE kit from Becton Dickinson) was used for the estimation of CD19 antibodies bound per cell. Further, CD38 and CD86 antibodies were used to characterize the B-cell subsets. All cytometric measurements were performed using a standardized BD LSR Fortessa platform. After 3 years of follow-up, patients’ data about disease activity and current medication were obtained.Results:22 SLE patients were treated with hydroxychloroquine (85.8%) and 19 patients received mycophenolate mofetil (MMF; n=14; 54.6%) or azathioprine (AZA; n= 5; 19.5 %). 5 patients were treated with other DMARDs. Independently of hydroxychloroquine and/or MMF, no significant differences were seen in naïve, non-switched memory, post-switched memory, plasma blasts, B1- or MBL-like B-cells. Patients treated with AZA had significantly lower naïve B-cells (mean±SD, 39.3±6.7vs. 73.1±19.3 %; p = 0.028), but had significantly higher IgD-post switched B-cells (31.2±9.1 vs.12.5 ±9.2 %; p = 0.028, respectively) compared with no AZA-treatment. Interestingly, activated B-cells (5.5±1.5 vs. 1.8±1.1%; p = 0.009) were significantly higher in AZA-treated. After 3 years of follow-up, almost all patients were in remission (median±SE, SLEDAI of 2.0±2.0), except of 3 patients with a SLEDAI of ≥ 6. Interestingly, those patients had at baseline, statistically higher naïve B-cells (p = 0.041) and lower B1-like B-cells (p =0.020) compared with patients with low disease activity.Conclusion:Our results suggest that independently of hydroxychloroquine and/or MMF treatment, all patients with low disease activity had similar normal B-cell subsets. Interestingly, in the small group of patients who were treated with AZA, a reduced regeneration of B-cells was shown. Patients with higher disease and high naïve B-cells showed an increased disease activity after three years.Acknowledgments:The research was performed in “CBmed” and funded by the Austrian Federal Government within the COMET K1 Centre Program, Land Steiermark and Land Wien.Disclosure of Interests:None declared

scholarly journals Molecular characteristics of antibodies bearing an anti-DNA-associated idiotype.

1991 ◽  
Vol 174 (6) ◽  
pp. 1639-1652 ◽  
Author(s):  
A Manheimer-Lory ◽  
J B Katz ◽  
M Pillinger ◽  
C Ghossein ◽  
A Smith ◽  
...  
Keyword(s):  
B Cells ◽  
Dna Binding ◽  
Lupus Erythematosus ◽  
Germ Line ◽  
High Titer ◽  
Variable Region ◽  
Amino Acid Sequences ◽  
Molecular Characteristics ◽  
Systemic Lupus ◽  
Dna Antibodies

Anti-double-stranded DNA antibodies are the hallmark of the disease systemic lupus erythematosus and are believed to contribute to pathogenesis. While a large number of anti-DNA antibodies from mice with lupus-like syndromes have been characterized and their variable region genes sequenced, few human anti-DNA antibodies have been reported. We describe here the variable region gene sequences of eight antibodies produced by Epstein-Barr virus (EBV)-transformed B cells that bear the 3I idiotype, an idiotype expressed on anti-DNA antibodies and present in high titer in patients with systemic lupus. The comparison of these antibodies to the light chains of 3I+ myeloma proteins and serum antibodies reveals that EBV transformation yields B cells producing antibodies representative of the expressed antibody repertoire. The analysis of nucleotide and amino acid sequences of these antibodies suggests the first complementarity determining region of the light chain may be important in DNA binding and that paradigms previously generated to account for DNA binding require modification. The understanding of the molecular genetics of the anti-DNA response requires a more complete description of the immunoglobulin germ line repertoire, but data reported here suggest that somatic diversification is a characteristic of the anti-DNA response.

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