scholarly journals The Charcot Lecture | Beating MS: A story of B cells, with twists and turns

2014 ◽  
Vol 21 (1) ◽  
pp. 8-21 ◽  
Author(s):  
Stephen L Hauser
Keyword(s):  
B Cells ◽  
Plasma Cells ◽  
Clinical Medicine ◽  
Affinity Maturation ◽  
Lessons Learned ◽  
Phase Ii Trials ◽  
Humoral Immune ◽  
Beneficial Effects ◽  
Inflammatory Phase ◽  
Humoral Immune System

Autoimmune B cells play a major role in mediating tissue damage in multiple sclerosis (MS). In MS, B cells are believed to cross the blood-brain barrier and undergo stimulation, antigen-driven affinity maturation and clonal expansion within the supportive CNS environment. These highly restricted populations of clonally expanded B cells and plasma cells can be detected in MS lesions, in cerebrospinal fluid, and also in peripheral blood. In phase II trials in relapsing MS, monoclonal antibodies that target circulating CD20-positive B lymphocytes dramatically reduced disease activity. These beneficial effects occurred within weeks of treatment, indicating that a direct effect on B cells—and likely not on putative autoantibodies—was responsible. The discovery that depletion of B cells has an impact on MS biology enabled a paradigm shift in understanding how the inflammatory phase of MS develops, and will hopefully lead to development of increasingly selective therapies against culprit B cells and related humoral immune system pathways. More broadly, these studies illustrate how lessons learned from the bedside have unique power to inform translational research. They highlight the essential role of clinician scientists, currently endangered, who navigate the rocky and often unpredictable terrain between the worlds of clinical medicine and biomedical research.

scholarly journals The generation of plasma cells and CD27−IgD−B cells during Hantavirus infection are associated with distinct pathological findings

2019 ◽  
Author(s):  
PF Kerkman ◽  
A Dernstedt ◽  
L Tadala ◽  
E Mittler ◽  
M Dannborg ◽  
...  
Keyword(s):  
B Cells ◽  
Plasma Cells ◽  
Hemorrhagic Fever ◽  
Molecular Target ◽  
Extracellular Atp ◽  
Hantavirus Infection ◽  
Pathological Findings ◽  
Kidney Dysfunction ◽  
Humoral Immune ◽  
Humoral Immune System

AbstractHuman hantavirus infections can cause hemorrhagic fever with renal syndrome (HFRS), major signs of the disease being thrombocytopenia and transient kidney dysfunction. By a comprehensive and longitudinal study of circulating B cells, we demonstrate that these two pathologies associate with distinct effects on the humoral immune system during HFRS. Low thrombocyte counts strongly associated with an abnormal frequency of plasmablasts in circulation, whereas kidney dysfunction was indicative of an accumulation of CD27−B cells and plasmablasts. Finally, we provide evidence that high levels of extracellular ATP in circulation during HFRS correlates with shedding of surface CD27 on B cells via a metallomatrix proteinase-8-mediated mechanism. Since extracellular ATP is known to regulate kidney function, our study reveals a link between kidney dysfunction and the generation of CD27−IgD−B cells, and a potential molecular target for treatment of the symptomatic phase of HFRS.

scholarly journals IL-21 acts directly on B cells to regulate Bcl-6 expression and germinal center responses

2010 ◽  
Vol 207 (2) ◽  
pp. 353-363 ◽  
Author(s):  
Michelle A. Linterman ◽  
Laura Beaton ◽  
Di Yu ◽  
Roybel R. Ramiscal ◽  
Monika Srivastava ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Cell Formation ◽  
Affinity Maturation ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Early Memory ◽  
Bone Marrow Chimeras ◽  
Follicular Response

During T cell–dependent responses, B cells can either differentiate extrafollicularly into short-lived plasma cells or enter follicles to form germinal centers (GCs). Interactions with T follicular helper (Tfh) cells are required for GC formation and for selection of somatically mutated GC B cells. Interleukin (IL)-21 has been reported to play a role in Tfh cell formation and in B cell growth, survival, and isotype switching. To date, it is unclear whether the effect of IL-21 on GC formation is predominantly a consequence of this cytokine acting directly on the Tfh cells or if IL-21 directly influences GC B cells. We show that IL-21 acts in a B cell–intrinsic fashion to control GC B cell formation. Mixed bone marrow chimeras identified a significant B cell–autonomous effect of IL-21 receptor (R) signaling throughout all stages of the GC response. IL-21 deficiency profoundly impaired affinity maturation and reduced the proportion of IgG1+ GC B cells but did not affect formation of early memory B cells. IL-21R was required on GC B cells for maximal expression of Bcl-6. In contrast to the requirement for IL-21 in the follicular response to sheep red blood cells, a purely extrafollicular antibody response to Salmonella dominated by IgG2a was intact in the absence of IL-21.

scholarly journals Hyperproliferation of B Cells Specific for a Weakly Immunogenic PorA in a Meningococcal Vaccine Model

2008 ◽  
Vol 15 (10) ◽  
pp. 1598-1605 ◽  
Author(s):  
Thomas A. Luijkx ◽  
Jacqueline A. M. van Gaans-van den Brink ◽  
Harry H. van Dijken ◽  
Germie P. J. M. van den Dobbelsteen ◽  
Cécile A. C. M. van Els
Keyword(s):  
B Cells ◽  
B Cell ◽  
Bactericidal Activity ◽  
Plasma Cells ◽  
Affinity Maturation ◽  
Memory B Cells ◽  
Vaccine Antigen ◽  
Cell Subpopulation ◽  
Cell Subpopulations ◽  
Group B

ABSTRACT Highly homologous meningococcal porin A (PorA) proteins induce protective humoral immunity against Neisseria meningitidis group B infection but with large and consistent differences in the levels of serum bactericidal activity achieved. We investigated whether a poor PorA-specific serological outcome is associated with a limited size of the specific B-cell subpopulation involved. The numbers of PorA-specific splenic plasma cells, bone marrow (BM) plasma cells, and splenic memory B cells were compared between mice that received priming and boosting with the weakly immunogenic PorA (P1.7-2,4) protein and those that received priming and boosting with the highly immunogenic PorA (P1.5-1,2-2) protein. Immunoglobulin G (IgG) titers (except at day 42), bactericidal activity, and the avidity of IgG produced against P1.7-2,4 were significantly lower at all time points after priming and boosting than against P1.5-1,2-2. These differences, however, were not associated with a lack of P1.7-2,4-specific plasma cells. Instead, priming with both of the PorAs resulted in the initial expansion of comparable numbers of splenic and BM plasma cells. Moreover, P1.7-2,4-specific BM plasma cells, but not P1.5-1,2-2-specific plasma cells, expanded significantly further after boosting. Likewise, after a relative delay during the priming phase, the splenic P1.7-2,4-specific memory B cells largely outnumbered those specific for P1.5-1,2-2, upon boosting. These trends were observed with different vaccine formulations of the porins. Our results show for the first time that B-cell subpopulations involved in a successfully maturated antibody response against a clinically relevant vaccine antigen are maintained at smaller population sizes than those associated with poor affinity maturation. This bears consequences for the interpretation of immunological memory data in clinical vaccine trials.

scholarly journals Memory persistence and differentiation into antibody-secreting cells accompanied by positive selection in longitudinal BCR repertoires

2022 ◽  
Author(s):  
Artem I. Mikelov ◽  
Evgeniia I. Alekseeva ◽  
Ekaterina A. Komech ◽  
Dmitriy B. Staroverov ◽  
Maria A. Turchaninova ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Peripheral Blood ◽  
Plasma Cells ◽  
Inflammatory Diseases ◽  
Affinity Maturation ◽  
Memory B Cells ◽  
Immune Memory ◽  
Memory B Cell ◽  
Antibody Secreting Cells

B-cell mediated immune memory holds both plasticity and conservatism to respond to new challenges and repeated infections. Here, we analyze the dynamics of immunoglobulin heavy chain (IGH) repertoires of memory B cells, plasmablasts and plasma cells sampled several times during one year from peripheral blood of volunteers without severe inflammatory diseases. We reveal a high degree of clonal persistence in individual memory B-cell subsets with inter-individual convergence in memory and antibody-secreting cells (ASCs). Clonotypes in ASCs demonstrate clonal relatedness to memory B cells and are transient in peripheral blood. Two clusters of expanded clonal lineages displayed different prevalence of memory B cells, isotypes, and persistence. Phylogenetic analysis revealed signs of reactivation of persisting memory B cell-enriched clonal lineages, accompanied by new rounds of affinity maturation during proliferation to ASCs. Negative selection contributes to both, persisting and reactivated lineages, saving functionality and specificity of BCRs to protect from the current and future pathogens.

Bim establishes the B-cell repertoire from early to late in the immune response

2020 ◽  
Author(s):  
Akiko Sugimoto-Ishige ◽  
Michishige Harada ◽  
Miho Tanaka ◽  
Tommy Terooatea ◽  
Yu Adachi ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Affinity Maturation ◽  
Late Response ◽  
Cell Repertoire ◽  
High Affinity ◽  
B Cell Repertoire

Abstract In T cell-dependent antibody responses, some of the activated B cells differentiate along extrafollicular pathways into low-affinity memory and plasma cells, whereas others are involved in subsequent germinal center (GC) formation in follicular pathways, in which somatic hypermutation and affinity maturation occur. The present study demonstrated that Bim, a proapoptotic BH3-only member of the Bcl-2 family, contributes to the establishment of the B-cell repertoire from early to late stages of immune responses to T cell-dependent antigens. Extrafollicular plasma cells grew in the spleen during the early immune response, but their numbers rapidly declined with the appearance of GC-derived progeny in wild-type mice. By contrast, conditional Bim deficiency in B cells resulted in expansion of extrafollicular IgG1+ antibody-forming cells (AFCs) and this expansion was sustained during the late response, which hampered the formation of GC-derived high-affinity plasma cells in the spleen. Approximately 10% of AFCs in mutant mice contained mutated VH genes; thus, Bim deficiency appears not to impede the selection of high-affinity AFC precursor cells. These results suggest that Bim contributes to the replacement of low-affinity antibody by high-affinity antibody as the immune response progresses.

The Underappreciated Role of the Humoral Immune System and B Cells in Tumorigenesis and Cancer Therapeutics: A Review

2020 ◽  
Vol 108 (1) ◽  
pp. 38-45
Author(s):  
Victor E. Chen ◽  
Benjamin A. Greenberger ◽  
James M. Taylor ◽  
Martin J. Edelman ◽  
Bo Lu
Keyword(s):  
Immune System ◽  
B Cells ◽  
Cancer Therapeutics ◽  
Humoral Immune ◽  
Humoral Immune System

scholarly journals Intrinsic properties of human germinal center B cells set antigen affinity thresholds

2018 ◽  
Vol 3 (29) ◽  
pp. eaau6598 ◽  
Author(s):  
Kihyuck Kwak ◽  
Nicolas Quizon ◽  
Haewon Sohn ◽  
Avva Saniee ◽  
Javier Manzella-Lapeira ◽  
...  
Keyword(s):  
B Cells ◽  
Germinal Center ◽  
Synapse Formation ◽  
Plasma Cells ◽  
Affinity Maturation ◽  
Intrinsic Properties ◽  
High Affinity ◽  
Follicular Helper ◽  
Bcr Signaling ◽  
Engagement And Disengagement

Protective antibody responses to vaccination or infection depend on affinity maturation, a process by which high-affinity germinal center (GC) B cells are selected on the basis of their ability to bind, gather, and present antigen to T follicular helper (Tfh) cells. Here, we show that human GC B cells have intrinsically higher-affinity thresholds for both B cell antigen receptor (BCR) signaling and antigen gathering as compared with naïve B cells and that these functions are mediated by distinct cellular structures and pathways that ultimately lead to antigen affinity– and Tfh cell–dependent differentiation to plasma cells. GC B cells bound antigen through highly dynamic, actin- and ezrin-rich pod-like structures that concentrated BCRs. The behavior of these structures was dictated by the intrinsic antigen affinity thresholds of GC B cells. Low-affinity antigens triggered continuous engagement and disengagement of membrane-associated antigens, whereas high-affinity antigens induced stable synapse formation. The pod-like structures also mediated affinity-dependent antigen internalization by unconventional pathways distinct from those of naïve B cells. Thus, intrinsic properties of human GC B cells set thresholds for affinity selection.

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 The origins, function, and regulation of T follicular helper cells

2012 ◽  
Vol 209 (7) ◽  
pp. 1241-1253 ◽  
Author(s):  
Cindy S. Ma ◽  
Elissa K. Deenick ◽  
Marcel Batten ◽  
Stuart G. Tangye
Keyword(s):  
B Cells ◽  
Plasma Cells ◽  
Natural Infection ◽  
Critical Role ◽  
Cell Formation ◽  
T Follicular Helper Cells ◽  
Humoral Immune ◽  
Helper Cells ◽  
Follicular Helper ◽  
Immunological Diseases

The generation of high-affinity antibodies (Abs) plays a critical role in the neutralization and clearance of pathogens and subsequent host survival after natural infection with a variety of microorganisms. Most currently available vaccines rely on the induction of long-lived protective humoral immune responses by memory B cells and plasma cells, underscoring the importance of Abs in host protection. Ab responses against most antigens (Ags) require interactions between B cells and CD4+ T helper cells, and it is now well recognized that T follicular helper cells (Tfh) specialize in providing cognate help to B cells and are fundamentally required for the generation of T cell–dependent B cell responses. Perturbations in the development and/or function of Tfh cells can manifest as immunopathologies, such as immunodeficiency, autoimmunity, and malignancy. Unraveling the cellular and molecular requirements underlying Tfh cell formation and maintenance will help to identify molecules that could be targeted for the treatment of immunological diseases that are characterized by insufficient or excessive Ab responses.

scholarly journals Positive Selection in the Light Zone of Germinal Centers

2021 ◽  
Vol 12 ◽  
Author(s):  
Rinako Nakagawa ◽  
Dinis Pedro Calado
Keyword(s):  
B Cells ◽  
Positive Selection ◽  
B Cell ◽  
Plasma Cells ◽  
Selection Process ◽  
Germinal Centers ◽  
Affinity Maturation ◽  
Memory B Cells ◽  
Cell Fates ◽  
High Affinity

Germinal centers (GCs) are essential sites for the production of high-affinity antibody secreting plasma cells (PCs) and memory-B cells (MBCs), which form the framework of vaccination. Affinity maturation and permissive selection in GCs are key for the production of PCs and MBCs, respectively. For these purposes, GCs positively select “fit” cells in the light zone of the GC and instructs them for one of three known B cell fates: PCs, MBCs and persistent GC-B cells as dark zone entrants. In this review, we provide an overview of the positive selection process and discuss its mechanisms and how B cell fates are instructed.

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