Faculty Opinions recommendation of Restricted clonality and limited germinal center reentry characterize memory B cell reactivation by boosting.

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.

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BOB.1 controls memory B-cell fate in the germinal center reaction

Journal of Autoimmunity ◽

10.1016/j.jaut.2019.04.011 ◽

2019 ◽

Vol 101 ◽

pp. 131-144 ◽

Cited By ~ 2

Author(s):

Maartje J. Levels ◽

Cynthia M. Fehres ◽

Lisa G.M. van Baarsen ◽

Nathalie O.P. van Uden ◽

Kristine Germar ◽

...

Keyword(s):

B Cell ◽

Cell Fate ◽

Germinal Center ◽

Memory B Cell ◽

Germinal Center Reaction

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Quantitatively Reduced Participation of Anti-Nuclear Antigen B Cells That Down-Regulate B Cell Receptor during Primary Development in the Germinal Center/Memory B Cell Response to Foreign Antigen

The Journal of Immunology ◽

10.4049/jimmunol.178.9.5623 ◽

2007 ◽

Vol 178 (9) ◽

pp. 5623-5634 ◽

Cited By ~ 18

Author(s):

Boris Alabyev ◽

Ziaur S. M. Rahman ◽

Tim Manser

Keyword(s):

B Cells ◽

B Cell ◽

Germinal Center ◽

Cell Response ◽

Cell Receptor ◽

B Cell Receptor ◽

Nuclear Antigen ◽

Memory B Cell ◽

Foreign Antigen ◽

Antigen B

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Human memory B cells originate from three distinct germinal center-dependent and -independent maturation pathways

Blood ◽

10.1182/blood-2011-04-345579 ◽

2011 ◽

Vol 118 (8) ◽

pp. 2150-2158 ◽

Cited By ~ 217

Author(s):

Magdalena A. Berkowska ◽

Gertjan J. A. Driessen ◽

Vasilis Bikos ◽

Christina Grosserichter-Wagener ◽

Kostas Stamatopoulos ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Germinal Center ◽

Somatic Hypermutation ◽

Phenotypic Diversity ◽

Human Memory ◽

Memory B Cells ◽

Memory B Cell ◽

Effector Cells ◽

B Cell Subsets

Abstract Multiple distinct memory B-cell subsets have been identified in humans, but it remains unclear how their phenotypic diversity corresponds to the type of responses from which they originate. Especially, the contribution of germinal center-independent responses in humans remains controversial. We defined 6 memory B-cell subsets based on their antigen-experienced phenotype and differential expression of CD27 and IgH isotypes. Molecular characterization of their replication history, Ig somatic hypermutation, and class-switch profiles demonstrated their origin from 3 different pathways. CD27−IgG+ and CD27+IgM+ B cells are derived from primary germinal center reactions, and CD27+IgA+ and CD27+IgG+ B cells are from consecutive germinal center responses (pathway 1). In contrast, natural effector and CD27−IgA+ memory B cells have limited proliferation and are also present in CD40L-deficient patients, reflecting a germinal center-independent origin. Natural effector cells at least in part originate from systemic responses in the splenic marginal zone (pathway 2). CD27−IgA+ cells share low replication history and dominant Igλ and IgA2 use with gut lamina propria IgA+ B cells, suggesting their common origin from local germinal center-independent responses (pathway 3). Our findings shed light on human germinal center-dependent and -independent B-cell memory formation and provide new opportunities to study these processes in immunologic diseases.

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Multiscale Modeling of Germinal Center Recapitulates the Temporal Transition From Memory B Cells to Plasma Cells Differentiation as Regulated by Antigen Affinity-Based Tfh Cell Help

Frontiers in Immunology ◽

10.3389/fimmu.2020.620716 ◽

2021 ◽

Vol 11 ◽

Author(s):

Elena Merino Tejero ◽

Danial Lashgari ◽

Rodrigo García-Valiente ◽

Xuefeng Gao ◽

Fabien Crauste ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Cell Fate ◽

Plasma Cell ◽

Germinal Center ◽

Plasma Cells ◽

Asymmetric Division ◽

Memory B Cells ◽

Memory B Cell ◽

Germinal Center Reaction

Germinal centers play a key role in the adaptive immune system since they are able to produce memory B cells and plasma cells that produce high affinity antibodies for an effective immune protection. The mechanisms underlying cell-fate decisions are not well understood but asymmetric division of antigen, B-cell receptor affinity, interactions between B-cells and T follicular helper cells (triggering CD40 signaling), and regulatory interactions of transcription factors have all been proposed to play a role. In addition, a temporal switch from memory B-cell to plasma cell differentiation during the germinal center reaction has been shown. To investigate if antigen affinity-based Tfh cell help recapitulates the temporal switch we implemented a multiscale model that integrates cellular interactions with a core gene regulatory network comprising BCL6, IRF4, and BLIMP1. Using this model we show that affinity-based CD40 signaling in combination with asymmetric division of B-cells result in switch from memory B-cell to plasma cell generation during the course of the germinal center reaction. We also show that cell fate division is unlikely to be (solely) based on asymmetric division of Ag but that BLIMP1 is a more important factor. Altogether, our model enables to test the influence of molecular modulations of the CD40 signaling pathway on the production of germinal center output cells.

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Germinal center activity and B cell maturation promote protective antibody responses against Plasmodium pre-erythrocytic infection

10.1101/2021.09.10.459481 ◽

2021 ◽

Author(s):

Ganesh Ram R. Visweswaran ◽

Kamalakannan Vijayan ◽

Ramyavardhanee Chandrasekaran ◽

Olesya Trakhimets ◽

Samantha L. Whiteside ◽

...

Keyword(s):

B Cell ◽

Germinal Center ◽

Antibody Responses ◽

Cell Maturation ◽

Mouse Strains ◽

Specific Class ◽

Memory B Cell ◽

Protective Antibody ◽

B Cell Maturation ◽

Center Activity

AbstractBlocking Plasmodium, the causative agent of malaria, at the asymptomatic pre-erythrocytic stage would abrogate disease pathology and prevent transmission. Rodent-infectious species of Plasmodium such as P. yoelii (Py) serve as key tools to study vaccine efficacy and disease biology in immune-competent experimental animals. Here we evaluated the differences in vaccine-elicited humoral immunity in two widely used, and vastly diverged, inbred mouse strains, BALB/cJ and C57BL/6J, and identified immunological factors associated with protection. We vaccinated with Py circumsporozoite protein (CSP), the major surface antigen on the sporozoite, and evaluated protective efficacy after mosquito bite challenge. Vaccination achieved 60% sterile protection and otherwise delayed blood stage patency in BALB/cJ mice, whereas; all C57BL/6J mice were infected similar to controls. Interestingly, protection was mediated by antibodies, and could be passively transferred from immunized BALB/cJ mice into naïve C57BL/6J. Dissection of the underlying immunological features of protection revealed early deficits in antibody titers and polyclonal avidity in C57BL/6J mice. Additionally, PyCSP-vaccination in BALB/cJ induced a significantly higher proportion of antigen-specific B-cells and class-switched memory B-cell (MBCs) populations than in C57BL/6J mice. Strikingly, C57BL/6J mice also had markedly fewer germinal center experienced, CSP-specific class-switched MBCs compared to BALB/cJ mice. Analysis of the IgG γ chain repertoires by next generation sequencing in PyCSP-specific memory B-cell repertoires also revealed higher somatic hypermutation rates in BALB/cJ mice than in C57BL/6J mice. These findings indicate that BALB/cJ mice achieved higher levels of B cell maturation in response to vaccination with PyCSP, which likely enabled the development of protective antibody responses. Overall, our study indicates that germinal center activity and B cell maturation are key processes in the development of vaccine-elicited protective antibodies against CSP.

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