scholarly journals A pathogenic and clonally expanded B cell transcriptome in active multiple sclerosis

2020 ◽  
Vol 117 (37) ◽  
pp. 22932-22943 ◽  
Author(s):  
Akshaya Ramesh ◽  
Ryan D. Schubert ◽  
Ariele L. Greenfield ◽  
Ravi Dandekar ◽  
Rita Loudermilk ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
B Cell ◽  
Single Cell ◽  
Rna Sequencing ◽  
Chemokine Receptors ◽  
Plasma Cells ◽  
Cholesterol Biosynthesis ◽  
Memory B Cells ◽  
Cell Phenotype

Central nervous system B cells have several potential roles in multiple sclerosis (MS): secretors of proinflammatory cytokines and chemokines, presenters of autoantigens to T cells, producers of pathogenic antibodies, and reservoirs for viruses that trigger demyelination. To interrogate these roles, single-cell RNA sequencing (scRNA-Seq) was performed on paired cerebrospinal fluid (CSF) and blood from subjects with relapsing-remitting MS (RRMS; n = 12), other neurologic diseases (ONDs; n = 1), and healthy controls (HCs; n = 3). Single-cell immunoglobulin sequencing (scIg-Seq) was performed on a subset of these subjects and additional RRMS (n = 4), clinically isolated syndrome (n = 2), and OND (n = 2) subjects. Further, paired CSF and blood B cell subsets (RRMS; n = 7) were isolated using fluorescence activated cell sorting for bulk RNA sequencing (RNA-Seq). Independent analyses across technologies demonstrated that nuclear factor kappa B (NF-κB) and cholesterol biosynthesis pathways were activated, and specific cytokine and chemokine receptors were up-regulated in CSF memory B cells. Further, SMAD/TGF-β1 signaling was down-regulated in CSF plasmablasts/plasma cells. Clonally expanded, somatically hypermutated IgM+ and IgG1+ CSF B cells were associated with inflammation, blood–brain barrier breakdown, and intrathecal Ig synthesis. While we identified memory B cells and plasmablast/plasma cells with highly similar Ig heavy-chain sequences across MS subjects, similarities were also identified with ONDs and HCs. No viral transcripts, including from Epstein–Barr virus, were detected. Our findings support the hypothesis that in MS, CSF B cells are driven to an inflammatory and clonally expanded memory and plasmablast/plasma cell phenotype.

IgM+ memory B cells induced in response to Plasmodium berghei adopt a germinal centre B cell phenotype during secondary infection

Parasitology ◽  
2020 ◽  
Vol 147 (9) ◽  
pp. 994-998 ◽  
Author(s):  
Halina M. Pietrzak ◽  
Lisa J. Ioannidis ◽  
Diana S. Hansen
Keyword(s):  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Secondary Infection ◽  
Memory B Cells ◽  
Germinal Centre ◽  
Cell Phenotype ◽  
Memory B Cell ◽  
Humoral Immune ◽  
Transfer Strategies

AbstractEmerging evidence started to delineate multiple layers of memory B cells, with distinct effector functions during recall responses. Whereas most studies examining long-lived memory B cell responses have focussed on the IgG+ memory B cell compartment, IgM+ memory B cells have only recently started to receive attention. It has been proposed that unlike IgG+ memory B cells, which differentiate into antibody-secreting plasma cells upon antigen re-encounter, IgM+ memory B cells might have the additional capacity to establish secondary germinal centre (GC) responses. The precise function of IgM+ memory B cells in the humoral immune response to malaria has not been fully defined. Using a murine model of severe malaria infection and adoptive transfer strategies we found that IgM+ memory B cells induced in responses to P. berghei ANKA readily proliferate upon re-infection and adopt a GC B cell-like phenotype. The results suggest that that IgM+ memory B cells might play an important role in populating secondary GCs after re-infection with Plasmodium, thereby initiating the induction of B cell clones with enhanced affinity for antigen, at faster rates than naive B cells.

scholarly journals Rituximab-resistant splenic memory B cells and newly engaged naive B cells fuel relapses in patients with immune thrombocytopenia

2021 ◽  
Vol 13 (589) ◽  
pp. eabc3961
Author(s):  
Etienne Crickx ◽  
Pascal Chappert ◽  
Aurélien Sokal ◽  
Sandra Weller ◽  
Imane Azzaoui ◽  
...  
Keyword(s):  
B Cells ◽  
Autoimmune Diseases ◽  
B Cell ◽  
Single Cell ◽  
Immune Thrombocytopenia ◽  
Plasma Cells ◽  
Surface Expression ◽  
Memory B Cells ◽  
Gene Repertoire ◽  
Immunoglobulin Gene

Rituximab (RTX), an antibody targeting CD20, is widely used as a first-line therapeutic strategy in B cell–mediated autoimmune diseases. However, a large proportion of patients either do not respond to the treatment or relapse during B cell reconstitution. Here, we characterize the cellular basis responsible for disease relapse in secondary lymphoid organs in humans, taking advantage of the opportunity offered by therapeutic splenectomy in patients with relapsing immune thrombocytopenia. By analyzing the B and plasma cell immunoglobulin gene repertoire at bulk and antigen-specific single-cell level, we demonstrate that relapses are associated with two responses coexisting in germinal centers and involving preexisting mutated memory B cells that survived RTX treatment and naive B cells generated upon reconstitution of the B cell compartment. To identify distinctive characteristics of the memory B cells that escaped RTX-mediated depletion, we analyzed RTX refractory patients who did not respond to treatment at the time of B cell depletion. We identified, by single-cell RNA sequencing (scRNA-seq) analysis, a population of quiescent splenic memory B cells that present a unique, yet reversible, RTX-shaped phenotype characterized by down-modulation of B cell–specific factors and expression of prosurvival genes. Our results clearly demonstrate that these RTX-resistant autoreactive memory B cells reactivate as RTX is cleared and give rise to plasma cells and further germinal center reactions. Their continued surface expression of CD19 makes them efficient targets for current anti-CD19 therapies. This study thus identifies a pathogenic contributor to autoimmune diseases that can be targeted by available therapeutic agents.

scholarly journals B-cell populations discriminate between pediatric- and adult-onset multiple sclerosis

2016 ◽  
Vol 4 (1) ◽  
pp. e309 ◽  
Author(s):  
Alexander Schwarz ◽  
Bettina Balint ◽  
Mirjam Korporal-Kuhnke ◽  
Sven Jarius ◽  
Kathrin von Engelhardt ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
B Cell ◽  
B Lymphocyte ◽  
Plasma Cells ◽  
Cross Sectional Study ◽  
Memory B Cells ◽  
Immunoglobulin M ◽  
Adult Onset ◽  
Cross Sectional

Objective:To comparatively assess the B-cell composition in blood and CSF of patients with pediatric-onset multiple sclerosis (pedMS) and adult-onset multiple sclerosis (adMS).Methods:In this cross-sectional study, we obtained blood and CSF samples from 25 patients with pedMS (8–18 years) and 40 patients with adMS (23–65 years) and blood specimens from 66 controls (1–55 years). By using multicolor flow cytometry, we identified naive, transitional, isotype class-switched memory, nonswitched memory, and double-negative memory B-cell subsets as well as plasmablasts (PB) and terminally differentiated plasma cells (PC). Flow cytometric data were compared to concentrations of B-cell-specific cytokines in serum and CSF as determined by ELISA.Results:Frequencies of circulating naive B-cells decreased with higher age in controls but not in patients with multiple sclerosis (MS). B-cell patterns in CSF differed between pedMS and adMS with an acute relapse: in pedMS-derived CSF samples, high frequencies of nonswitched memory B cells and PB were present, whereas class-switched memory B cells and PC dominated in the CSF of patients with adMS. In pedMS, PB were also elevated in the periphery. Accumulation of PB in the CSF correlated with high intrathecal CXCL-13 levels and augmented intrathecal synthesis of immunoglobulin G and immunoglobulin M.Conclusions:We demonstrate distinct changes in intrathecal B-cell homeostasis in patients with pedMS during active disease, which differ from those in adults by an expansion of plasmablasts in blood and CSF and similarly occur in prototypic autoantibody-driven autoimmune disorders. This emphasizes the particular importance of activated B-lymphocyte subsets for disease progression in the earliest clinical stages of MS.

scholarly journals Memory B Cells in Multiple Sclerosis: Emerging Players in Disease Pathogenesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Krista D. DiSano ◽  
Francesca Gilli ◽  
Andrew R. Pachner
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
B Cell ◽  
Antigen Presentation ◽  
Cytokine Production ◽  
Memory B Cells ◽  
Cell Phenotype ◽  
Effector Functions ◽  
Immunomodulatory Therapies ◽  
Antibody Secreting Cells

Multiple Sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. Once thought to be primarily driven by T cells, B cells are emerging as central players in MS immunopathogenesis. Interest in multiple B cell phenotypes in MS expanded following the efficacy of B cell-depleting agents targeting CD20 in relapsing-remitting MS and inflammatory primary progressive MS patients. Interestingly, these therapies primarily target non-antibody secreting cells. Emerging studies seek to explore B cell functions beyond antibody-mediated roles, including cytokine production, antigen presentation, and ectopic follicle-like aggregate formation. Importantly, memory B cells (Bmem) are rising as a key B cell phenotype to investigate in MS due to their antigen-experience, increased lifespan, and rapid response to stimulation. Bmem display diverse effector functions including cytokine production, antigen presentation, and serving as antigen-experienced precursors to antibody-secreting cells. In this review, we explore the cellular and molecular processes involved in Bmem development, Bmem phenotypes, and effector functions. We then examine how these concepts may be applied to the potential role(s) of Bmem in MS pathogenesis. We investigate Bmem both within the periphery and inside the CNS compartment, focusing on Bmem phenotypes and proposed functions in MS and its animal models. Finally, we review how current immunomodulatory therapies, including B cell-directed therapies and other immunomodulatory therapies, modify Bmem and how this knowledge may be harnessed to direct therapeutic strategies in MS.

scholarly journals Reduced peripheral blood regulatory B cell levels are not associated with the Expanded Disability Status Scale score in multiple sclerosis

2018 ◽  
Vol 46 (9) ◽  
pp. 3970-3978 ◽  
Author(s):  
Shujun Guo ◽  
Qingqing Chen ◽  
Xiaoli Liang ◽  
Mimi Mu ◽  
Jing He ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
Peripheral Blood ◽  
Plasma Cells ◽  
Serum Levels ◽  
Memory B Cells ◽  
Healthy Controls ◽  
Expanded Disability Status Scale ◽  
Disability Status ◽  
Edss Score

Objective To investigate levels of regulatory B (Breg) cells, plasma cells, and memory B cells in the peripheral blood, and interleukin (IL)-10 in the serum of multiple sclerosis (MS) patients, and to determine the correlation between Breg cell levels and the Expanded Disability Status Scale (EDSS) score. Methods Levels of Breg cells, plasma cells, and memory B cells in the peripheral blood of 12 MS patients were measured using flow cytometry. IL-10 serum levels were measured by enzyme-linked immunosorbent assay. The correlation between Breg cell levels and MS EDSS score was measured using Pearson’s correlation coefficient. Results Compared with healthy controls, MS patients had decreased levels of CD19+CD24hiCD38hi Breg cells in their peripheral blood and reduced serum levels of IL-10; however, the ratios of CD19+CD27hiCD38hi plasma cells and CD19+CD27+CD24hi memory B cells to total B cells did not differ significantly between healthy controls and MS patients. CD19+CD24hiCD38hi Breg cell levels in the peripheral blood of MS patients were not significantly correlated with MS EDSS score. Conclusion Peripheral blood CD19+CD24hiCD38hi Breg cell levels and serum IL-10 levels were reduced in MS patients compared with controls, but Breg cell levels were not correlated with MS EDSS score.

scholarly journals Signatures of B Cell Receptor Repertoire Following Pneumocystis Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Han Sun ◽  
Hu-Qin Yang ◽  
Kan Zhai ◽  
Zhao-Hui Tong
Keyword(s):  
B Cells ◽  
B Cell ◽  
Single Cell ◽  
Plasma Cells ◽  
Somatic Hypermutation ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Receptor Repertoire ◽  
Elevated Expression ◽  
Pneumocystis Infection

B cells play vital roles in host defense against Pneumocystis infection. However, the features of the B cell receptor (BCR) repertoire in disease progression remain unclear. Here, we integrated single-cell RNA sequencing and single-cell BCR sequencing of immune cells from mouse lungs in an uninfected state and 1–4 weeks post-infection in order to illustrate the dynamic nature of B cell responses during Pneumocystis infection. We identified continuously increased plasma cells and an elevated ratio of (IgA + IgG) to (IgD + IgM) after infection. Moreover, Pneumocystis infection was associated with an increasing naïve B subset characterized by elevated expression of the transcription factor ATF3. The proportion of clonal expanded cells progressively increased, while BCR diversity decreased. Plasma cells exhibited higher levels of somatic hypermutation than naïve B cells. Biased usage of V(D)J genes was observed, and the usage frequency of IGHV9-3 rose. Overall, these results present a detailed atlas of B cell transcriptional changes and BCR repertoire features in the context of Pneumocystis infection, which provides valuable information for finding diagnostic biomarkers and developing potential immunotherapeutic targets.

scholarly journals Potential anti-EBV effects associated with elevated interleukin-21 levels: a case report

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Kristian Assing ◽  
Christian Nielsen ◽  
Marianne Jakobsen ◽  
Charlotte B. Andersen ◽  
Kristin Skogstrand ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Plasma Cell ◽  
Germinal Center ◽  
Plasma Cells ◽  
Cell Formation ◽  
Memory B Cells ◽  
Memory B Cell

Abstract Background Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4+ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8+ T cells able to contain chronic virus infections. Case presentation We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4+ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8+ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pTFH, p = 0.01), reduced frequencies of peripheral CD4+ Bcl-6+ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pTFH formation, pTFH and CD4+ IL-21+ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman’s rho: − 0.86, p < 0.001. Conclusions To the best of our knowledge, this is the first report of elevated CD4+ IL-21+ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.

A reservoir of rituximab-resistant splenic memory B cells contributes to relapses after B-cell depletion therapy

2019 ◽  
Author(s):  
Etienne Crickx ◽  
Pascal Chappert ◽  
Sandra Weller ◽  
Aurélien Sokal ◽  
Imane Azzaoui ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Complete Response ◽  
Memory B Cells ◽  
Chain Gene ◽  
Gene Repertoire ◽  
Heavy Chain Gene ◽  
Immunoglobulin Heavy Chain Gene ◽  
Pathogenic Antibodies

AbstractImmune thrombocytopenia (ITP) is an autoimmune disease mediated by pathogenic antibodies directed against platelet antigens, including GPIIbIIIa. Taking advantage of spleen samples obtained from ITP patients, we characterized by multiples approaches the onset of disease relapses occurring after an initial complete response to rituximab. Analysis of splenic B cell immunoglobulin heavy chain gene repertoire at bulk level and from single anti-GPIIbIIIa B cells revealed that germinal centers were fueled by B cells originating from the ongoing lymphopoiesis, but also by rituximab-resistant memory B cells, both giving rise to anti-GPIIbIIIa plasma cells. We identified a population of splenic memory B cells that resisted rituximab through acquisition of a unique phenotype and contributed to relapses, providing a new target in B cell mediated autoimmune diseases.

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