scholarly journals The Choroid Plexus Is Permissive for a Preactivated Antigen-Experienced Memory B-Cell Subset in Multiple Sclerosis

2021 ◽  
Vol 11 ◽  
Author(s):  
Jürgen Haas ◽  
Henriette Rudolph ◽  
Leonardo Costa ◽  
Simon Faller ◽  
Saskia Libicher ◽  
...  

The role of B cells in multiple sclerosis (MS) is increasingly recognized. B cells undergo compartmentalized redistribution in blood and cerebrospinal fluid (CSF) during active MS, whereby memory B cells accumulate in the CSF. While B-cell trafficking across the blood–brain barrier has been intensely investigated, cellular diapedesis through the blood–CSF barrier (BCSFB) is incompletely understood. To investigate how B cells interact with the choroid plexus to transmigrate into the CSF we isolated circulating B cells from healthy donors (HC) and MS patients, utilized an inverted cell culture filter system of human choroid plexus papilloma (HIBCPP) cells to determine transmigration rates of B-cell subsets, immunofluorescence, and electron microscopy to analyze migration routes, and qRT-PCR to determine cytokines/chemokines mediating B-cell diapedesis. We also screened the transcriptome of intrathecal B cells from MS patients. We found, that spontaneous transmigration of HC- and MS-derived B cells was scant, yet increased significantly in response to B-cell specific chemokines CXCL-12/CXCL-13, was further boosted upon pre-activation and occurred via paracellular and transcellular pathways. Migrating cells exhibited upregulation of several genes involved in B-cell activation/migration and enhanced expression of chemokine receptors CXCR4/CXCR5, and were predominantly of isotype class switched memory phenotype. This antigen-experienced migratory subset displayed more pronounced chemotactic activities in MS than in HC and was retrieved in intrathecal B cells from patients with active MS. Trafficking of class-switched memory B cells was downscaled in a small cohort of natalizumab-exposed MS patients and the proportions of these phenotypes were reduced in peripheral blood yet were enriched intrathecally in patients who experienced recurrence of disease activity after withdrawal of natalizumab. Our findings highlight the relevance of the BCSFB as important gate for the entry of potentially harmful activated B cells into the CSF.

2021 ◽  
Author(s):  
Leonardo Costa ◽  
Jürgen Haas ◽  
Henriette Rudolph ◽  
Saskia Libicher ◽  
Sven Jarius ◽  
...  

Background: The role of B cells in multiple sclerosis (MS) is increasingly recognized. B cells undergo compartmentalized redistribution in blood and cerebrospinal fluid (CSF) during active MS, whereby memory B cells accumulate in the CSF. While B-cell trafficking across the blood– brain barrier has been intensely investigated, cellular diapedesis through the blood–CSF barrier (BCSFB) is incompletely understood. Objectives: To investigate how B cells interact with the choroid plexus to transmigrate into the CSF, we isolated circulating B cells from healthy donors (HC) and MS patients, utilized an inverted cell culture filter system of human choroid plexus papilloma (HIBCPP) cells to determine transmigration rates of B-cell subsets, immunofluorescence, and electron microscopy to analyze migration routes, and qRT-PCR to determine cytokines/chemokines mediating B-cell diapedesis. We also screened the transcriptome of intrathecal B cells from MS patients. Results: We found that spontaneous transmigration of HC- and MS-derived B cells was scant yet increased significantly in response to B-cell specific chemokines CXCL-12/CXCL-13, was further boosted upon pre-activation and occurred via paracellular and transcellular pathways. Migrating cells exhibited upregulation of several genes involved in B-cell activation/migration and enhanced expression of chemokine receptors CXCR4/CXCR5 and were predominantly of isotype class switched memory phenotype. This antigen-experienced migratory subset displayed more pronounced chemotactic activities in MS than in HC and was retrieved in intrathecal B cells from patients with active MS. Trafficking of class-switched memory B cells was downscaled in a small cohort of natalizumab-exposed MS patients and the proportions of these phenotypes were reduced in peripheral blood yet were enriched intrathecally in patients who experienced recurrence of disease activity after withdrawal of natalizumab. Conclusion: Our findings highlight the relevance of the BCSFB as an important gate for the entry of potentially harmful activated B cells into the CSF.


2019 ◽  
Vol 31 (12) ◽  
pp. 771-779 ◽  
Author(s):  
Sarah Leach ◽  
Ryo Shinnakasu ◽  
Yu Adachi ◽  
Masatoshi Momota ◽  
Chieko Makino-Okamura ◽  
...  

Memory B cells protect against heterologous influenza infection


2020 ◽  
Vol 11 ◽  
Author(s):  
Austin Negron ◽  
Olaf Stüve ◽  
Thomas G. Forsthuber

While the contribution of autoreactive CD4+ T cells to the pathogenesis of Multiple Sclerosis (MS) is widely accepted, the advent of B cell-depleting monoclonal antibody (mAb) therapies has shed new light on the complex cellular mechanisms underlying MS pathogenesis. Evidence supports the involvement of B cells in both antibody-dependent and -independent capacities. T cell-dependent B cell responses originate and take shape in germinal centers (GCs), specialized microenvironments that regulate B cell activation and subsequent differentiation into antibody-secreting cells (ASCs) or memory B cells, a process for which CD4+ T cells, namely follicular T helper (TFH) cells, are indispensable. ASCs carry out their effector function primarily via secreted Ig but also through the secretion of both pro- and anti-inflammatory cytokines. Memory B cells, in addition to being capable of rapidly differentiating into ASCs, can function as potent antigen-presenting cells (APCs) to cognate memory CD4+ T cells. Aberrant B cell responses are prevented, at least in part, by follicular regulatory T (TFR) cells, which are key suppressors of GC-derived autoreactive B cell responses through the expression of inhibitory receptors and cytokines, such as CTLA4 and IL-10, respectively. Therefore, GCs represent a critical site of peripheral B cell tolerance, and their dysregulation has been implicated in the pathogenesis of several autoimmune diseases. In MS patients, the presence of GC-like leptomeningeal ectopic lymphoid follicles (eLFs) has prompted their investigation as potential sources of pathogenic B and T cell responses. This hypothesis is supported by elevated levels of CXCL13 and circulating TFH cells in the cerebrospinal fluid (CSF) of MS patients, both of which are required to initiate and maintain GC reactions. Additionally, eLFs in post-mortem MS patient samples are notably devoid of TFR cells. The ability of GCs to generate and perpetuate, but also regulate autoreactive B and T cell responses driving MS pathology makes them an attractive target for therapeutic intervention. In this review, we will summarize the evidence from both humans and animal models supporting B cells as drivers of MS, the role of GC-like eLFs in the pathogenesis of MS, and mechanisms controlling GC-derived autoreactive B cell responses in MS.


2006 ◽  
Vol 203 (9) ◽  
pp. 2157-2164 ◽  
Author(s):  
Meggan Mackay ◽  
Anfisa Stanevsky ◽  
Tao Wang ◽  
Cynthia Aranow ◽  
Margaret Li ◽  
...  

The inappropriate expansion and activation of autoreactive memory B cells and plasmablasts contributes to loss of self-tolerance in systemic lupus erythematosus (SLE). Defects in the inhibitory Fc receptor, FcγRIIB, have been shown to contribute to B cell activation and autoimmunity in several mouse models of SLE. In this paper, we demonstrate that expression of FcγRIIB is routinely up-regulated on memory B cells in the peripheral blood of healthy controls, whereas up-regulation of FcγRIIB is considerably decreased in memory B cells of SLE patients. This directly correlates with decreased FcγRIIB-mediated suppression of B cell receptor–induced calcium (Ca2+) response in those B cells. We also found substantial overrepresentation of African-American patients among those who failed to up-regulate FcγRIIB. These results suggest that the inhibitory receptor, FcγRIIB, may be impaired at a critical checkpoint in SLE in the regulation of memory B cells; thus, FcγRIIB represents a novel target for therapeutic interventions in this disease.


2018 ◽  
Vol 2 ◽  
pp. 97 ◽  
Author(s):  
Luke Muir ◽  
Paul F. McKay ◽  
Velislava N. Petrova ◽  
Oleksiy V. Klymenko ◽  
Sven Kratochvil ◽  
...  

Background:Human memory B cells play a vital role in the long-term protection of the host from pathogenic re-challenge. In recent years the importance of a number of different memory B cell subsets that can be formed in response to vaccination or infection has started to become clear. To study memory B cell responses, cells can be culturedex vivo,allowing for an increase in cell number and activation of these quiescent cells, providing sufficient quantities of each memory subset to enable full investigation of functionality. However, despite numerous papers being published demonstrating bulk memory B cell culture, we could find no literature on optimised conditions for the study of memory B cell subsets, such as IgM+memory B cells.Methods:Following a literature review, we carried out a large screen of memory B cell expansion conditions to identify the combination that induced the highest levels of memory B cell expansion. We subsequently used a novel Design of Experiments approach to finely tune the optimal memory B cell expansion and differentiation conditions for human memory B cell subsets. Finally, we characterised the resultant memory B cell subpopulations by IgH sequencing and flow cytometry.Results:The application of specific optimised conditions induce multiple rounds of memory B cell proliferation equally across Ig isotypes, differentiation of memory B cells to antibody secreting cells, and importantly do not alter the Ig genotype of the stimulated cells. Conclusions:Overall, our data identify a memory B cell culture system that offers a robust platform for investigating the functionality of rare memory B cell subsets to infection and/or vaccination.


2018 ◽  
Author(s):  
J. Nechvatalova ◽  
S.J.W. Bartol ◽  
Z. Chovancova ◽  
L. Boon ◽  
M. Vlkova ◽  
...  

One Sentence SummaryHuman B cells with a genetic defect in IGHD develop normally in vivo, and do not have a competitive disadvantage to IgD-expressing B cells for developing into memory B cells.AbstractSurface immunoglobulin D (IgD) is co-expressed with IgM on naive mature B cells. Still, the role of surface IgD remains enigmatic even 50 years after its initial discovery. We here examined the in vivo role of surface IgD in human B-cell homeostasis and antibody responses in four individuals with heterozygous nonsense mutations in IGHD. All IGHD heterozygous individuals had normal numbers of B cells and serum immunoglobulins, and did not show signs of immunodeficiency or immune dysregulation. IgD+ and IgD– naive mature B cells were present in equal numbers and showed similar immunophenotypes, except for decreased expression of CD79b in the IgD– subset. Furthermore, both IgD+ and IgD– naive mature B cells had normal replication histories, similar capacities to differentiate into plasma cells upon in vitro stimulation, and Ig switched memory B cells showed similar levels of somatic hypermutations. Thus human B cells lacking IgD expression develop normally and generate immunological memory in vivo, suggesting that surface IgD might function more restricted in regulating of B-cell activation to specific antigenic structures.


2021 ◽  
Author(s):  
Pankaj Kumar Mishra ◽  
Natalie Bruiners ◽  
Rahul Ukey ◽  
Pratik Datta ◽  
Alberta Onyuka ◽  
...  

AbstractGiven the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the recent implementation of SARS-CoV-2 vaccination, we have much to learn about the duration of immune protection and the interface between the immune responses to infection and to vaccination. To address these questions, we monitored immune responses to SARS-CoV-2 infection in convalescent individuals over seven months and following mRNA vaccination. Spike Receptor-Binding-Domain (RBD)-specific circulating antibodies and plasma neutralizing activity generally decreased over time, whereas RBD-specific memory B cells persisted. Additionally, using antibody depletion techniques, we showed that the neutralizing activity of plasma specifically resides in the anti-RBD antibodies. More vigorous antibody and B cell responses to vaccination were observed in previously infected subjects relative to uninfected comparators, presumably due to immune priming by infection. SARS-CoV-2 infection also led to increased numbers of double negative B memory cells, which are described as a dysfunctional B cell subset. This effect was reversed by SARS-CoV-2 vaccination, providing a potential mechanistic explanation for the vaccination-induced reduction in symptoms in patients with “Long-COVID”.


2018 ◽  
Vol 5 (1) ◽  
pp. e000296 ◽  
Author(s):  
Molly K Hritzo Ahye ◽  
Amit Golding

Systemic lupus erythematosus (SLE) is a manifestation of hyperactivated lymphocytes and results, in part, from the loss of normal tolerance checkpoints. FOXO1 is a transcription factor involved at critical early and late B cell development checkpoints; however, its role in regulating peripheral B cell tolerance is not fully understood. We have applied our published approach for using imaging flow cytometry to study native FOXO1 localisation in human lymphocytes to peripheral blood samples from healthy individuals versus patients with SLE. We report, here, on dramatic cytoplasmic localisation of FOXO1 in two peripheral B cell SLE subsets: IgD-CD27+ (class-switched memory) B cells and IgD-CD27- (atypical memory) B cells. The latter, so-called ‘Double Negative’ (DN) B cells have previously been shown to be increased in SLE and enriched in autoreactive clones. Cytoplasmic-predominant FOXO1 (CytoFOX) B cells are significantly increased in patients with SLE as compared to healthy controls, and the levels of CytoFoOX DN B cells correlate directly with SLE disease activity. The highest abundance of CytoFox DN B cells was observed in African American females with SLE Disease Activity Index (SLEDAI)≥6. The phenotype of CytoFOX DN B cells in SLE includes uniquely low CD20 expression and high granularity/side scatter. As FOXO1 phosphorylation downstream of B cell receptor-dependent signalling is required for nuclear exclusion, CytoFOX B cells likely represent a high state of B cell activation with excess signalling and/or loss of phosphatase activity. We hypothesise that CytoFOX B cells in lupus represent a novel biomarker for the expansion of pathological, autoreactive B cells which may provide new insights into the pathophysiology of SLE.


2020 ◽  
Vol 117 (37) ◽  
pp. 22932-22943 ◽  
Author(s):  
Akshaya Ramesh ◽  
Ryan D. Schubert ◽  
Ariele L. Greenfield ◽  
Ravi Dandekar ◽  
Rita Loudermilk ◽  
...  

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.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 80-80
Author(s):  
Mohamed-Rachid Boulassel ◽  
Bader Yassine-Diab ◽  
Don Healey ◽  
Charles Nicolette ◽  
Rafick-Pierre Sékaly ◽  
...  

Abstract We demonstrated the enhancement of CD8-specific responses following the administration of an immune-based therapy consisting of dendritic cells (DC) electroporated with autologous amplified HIV-1 RNA and CD40 ligand (CD40 L) RNA manufactured by the Arcelis™ process in HIV patients receiving antiretroviral therapy (ART). We conducted a sub study on circulating B cell populations to further assess changes induced by this autologous DC therapy as CD40L is a major B cell co-stimulatory factor. To this end, we assessed B cell subset changes in relation to the proliferative capacity of CD4+ and CD8+ T cells response to DC targets containing the 4 HIV-1 antigens (Gag, Vpr, Rev, Nef). The co-expression of CD19, CD38, IgD, CD10, CD23, CD27, CD5, and CD138 were analyzed by multi-parametric flow cytometry to assess circulating B cell subsets such as naïve resting B-cells (Bm1), activated naïve B cells (Bm2), GC founder cells (Bm2’), centroblasts and centrocytes (Bm3 and Bm4), early memory B cells (eBm5), memory B cells (Bm5), IgD memory cells, plasma cells, and B-1 cells. Changes in B cells subsets were analyzed before and after the four intradermal injections of this immunotherapeutic product containing 1.2 × 107 DC. Ten ART treated subjects with undetectable viral load (< 50 copies/ml), median CD4+ count of 440 cells/μl (range: 316–1102), and with a CD4+ nadir > 200 cells/μl were studied. Throughout the study, no significant changes in CD4+ cell count, CD4/CD8 ratio, and no viral blips were noticed. The percentage of total B cells, Bm1, Bm2, Bm2′, eBm5, IgD memory, plasma cells, and B-1 cell subsets did not significantly change. However, a decrease in the percentage of Bm3 and Bm4 cells was found (0.36 [0.06–0.86] versus 0.11 [0.04–0.36]; P=0.05). Conversely, an important increase in the Bm5 cell subset was evidenced (10.4 [1.6–24.2] versus 18.1 [5.1–27.5]; P=0.005) suggesting a proliferation of B memory cells induced by DC immunization. In addition, the multifunctional and polyvalent CD8+ T cell proliferative responses to the 4 HIV genes used in this immunotherapy were noticed in 8 out of 9 subjects available for analysis and characterized by an effector memory phenotype. No CD4+ T cell immune responses were detected, consistent with the endogenous HLA class I loading of the antigens. Collectively, these results indicate that this immunotherapy induces an increase in the B memory cell population in the absence of inducing any clinically apparent autoimmunity along with strong HIV specific multifunctional CD8+ T cell specific immune responses.


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