scholarly journals IgM+ and IgG+ memory B cells represent heterogeneous populations capable of producing class-switched antibodies and germinal center B cells upon re-challenge with P. yoelii

2021 ◽  
Author(s):  
Susie L. Brown ◽  
Jonathan J. Bauer-Erickson ◽  
Juhyung Lee ◽  
Enatha Ntirandekura ◽  
Jason S. Stumhofer
Keyword(s):  
B Cells ◽  
Germinal Center ◽  
Fluorescent Protein ◽  
Heterogeneous Population ◽  
Memory B Cells ◽  
Surface Proteins ◽  
Surface Markers ◽  
Recall Response ◽  
And Function

AbstractMemory B cells (MBCs) are essential for maintaining long-term humoral immunity to infectious organisms, including Plasmodium. MBCs are a heterogeneous population whose function can be dictated by isotype or expression of particular surface proteins. Here, aided by the use of antigen-specific B cell tetramers, MBC populations were evaluated to discern their phenotype and function in response to infection with a non-lethal strain of P. yoelii. Infection of mice with P. yoelii 17X resulted in the production of three predominant MBC populations: somatically hypermutated isotype-switched (swIg+) and IgM+ MBCs that co-expressed CD73 and CD80, and CD73-CD80- unmutated swIg+ B cells. Re-challenge experiments indicated that IgG-producing cells dominated the recall response with minimal induction of IgM-secreting cells. Furthermore, using fluorescent protein expression as a surrogate for CD73 and CD80 co-expression, ZsGreen1+IgM+ MBCs gave rise to class switched IgG-producing plasmablasts that induced comparable titers of Ag-specific Abs as their swIg+ counterparts after adoptive transfer and P. yoelii infection. Moreover, ZsGreen1+ IgM+ and swIg+ MBCs gave rise to B cells with a germinal center phenotype. Together these data indicated that MBC function is not defined by immunoglobulin isotype, nor does co-expression of key surface markers limit the potential fate of MBCs after recall.

scholarly journals BAFFR controls early memory B cell responses but is dispensable for germinal center function

2020 ◽  
Vol 218 (2) ◽  
Author(s):  
Angelica W.Y. Lau ◽  
Vivian M. Turner ◽  
Katherine Bourne ◽  
Jana R. Hermes ◽  
Tyani D. Chan ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Memory B Cells ◽  
Term Survival ◽  
Cell Responses ◽  
Tnf Superfamily ◽  
Surface Receptor ◽  
Early Memory

The TNF superfamily ligand BAFF maintains the survival of naive B cells by signaling through its surface receptor, BAFFR. Activated B cells maintain expression of BAFFR after they differentiate into germinal center (GC) or memory B cells (MBCs). However, the functions of BAFFR in these antigen-experienced B cell populations remain unclear. Here, we show that B cell–intrinsic BAFFR does not play a significant role in the survival or function of GC B cells or in the generation of the somatically mutated MBCs derived from them. Instead, BAFF/BAFFR signaling was required to generate the unmutated, GC-independent MBCs that differentiate directly from activated B cell blasts early in the response. Furthermore, amplification of BAFFR signaling in responding B cells did not affect GCs or the generation of GC-derived MBCs but greatly expanded the GC-independent MBC response. Although BAFF/BAFFR signaling specifically controlled the formation of the GC-independent MBC response, both types of MBCs required input from this pathway for optimal long-term survival.

scholarly journals γ-Herpesvirus Latency Is Preferentially Maintained in Splenic Germinal Center and Memory B Cells

2002 ◽  
Vol 196 (10) ◽  
pp. 1363-1372 ◽  
Author(s):  
Emilio Flaño ◽  
In-Jeong Kim ◽  
David L. Woodland ◽  
Marcia A. Blackman
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Viral Gene Expression ◽  
Memory B Cells ◽  
Viral Gene ◽  
Long Latency ◽  
Cell Life ◽  
Unique System

The γ-herpesviruses are oncogenic B cell lymphotrophic viruses that establish life-long latency in the host. Murine γ-herpesvirus 68 (MHV-68) infection of mice represents a unique system for analyzing γ-herpesvirus latency in splenic B cells at different stages of infection. After intranasal infection with MHV-68 we analyzed the establishment of latency 14 days after infection, and the maintenance of latency 3 months after infection in different purified subpopulations of B cells in the spleen. The data show that MHV-68 latency is mainly established in germinal center B cells and that long-term latency is preferentially maintained in two different subsets of isotype-switched B cells, germinal center and memory B cells. Cell cycle analysis indicates that MHV-68 is located in both cycling and resting isotype-switched B cells. Analysis of viral gene expression showed that both lytic and latent viral transcripts were differentially expressed in germinal center and memory B cells during long-term latency. Together, these observations suggested that γ-herpesviruses exploit the B cell life cycle in the spleen.

scholarly journals Human Germinal Center B Cells Differ from Naïve and Memory B Cells in CD40 Expression and CD40L‐Induced Signaling Response

2019 ◽  
Vol 95 (4) ◽  
pp. 442-449 ◽  
Author(s):  
Kanutte Huse ◽  
Cara E. Wogsland ◽  
Hannah G. Polikowsky ◽  
Kirsten E. Diggins ◽  
Erlend B. Smeland ◽  
...  
Keyword(s):  
B Cells ◽  
Germinal Center ◽  
Memory B Cells ◽  
Cd40 Expression ◽  
Germinal Center B Cells

scholarly journals Regulation of the germinal center gene program by interferon (IFN) regulatory factor 8/IFN consensus sequence-binding protein

2005 ◽  
Vol 203 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Chang Hoon Lee ◽  
Mark Melchers ◽  
Hongsheng Wang ◽  
Ted A. Torrey ◽  
Rebecca Slota ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Transcriptional Activation ◽  
Germinal Center ◽  
Target Genes ◽  
Fluorescent Protein ◽  
Binding Protein ◽  
Consensus Sequence ◽  
B Cell Lymphoma ◽  
Regulatory Factor

Interferon (IFN) consensus sequence-binding protein/IFN regulatory factor 8 (IRF8) is a transcription factor that regulates the differentiation and function of macrophages, granulocytes, and dendritic cells through activation or repression of target genes. Although IRF8 is also expressed in lymphocytes, its roles in B cell and T cell maturation or function are ill defined, and few transcriptional targets are known. Gene expression profiling of human tonsillar B cells and mouse B cell lymphomas showed that IRF8 transcripts were expressed at highest levels in centroblasts, either from secondary lymphoid tissue or transformed cells. In addition, staining for IRF8 was most intense in tonsillar germinal center (GC) dark-zone centroblasts. To discover B cell genes regulated by IRF8, we transfected purified primary tonsillar B cells with enhanced green fluorescent protein–tagged IRF8, generated small interfering RNA knockdowns of IRF8 expression in a mouse B cell lymphoma cell line, and examined the effects of a null mutation of IRF8 on B cells. Each approach identified activation-induced cytidine deaminase (AICDA) and BCL6 as targets of transcriptional activation. Chromatin immunoprecipitation studies demonstrated in vivo occupancy of 5′ sequences of both genes by IRF8 protein. These results suggest previously unappreciated roles for IRF8 in the transcriptional regulation of B cell GC reactions that include direct regulation of AICDA and BCL6.

scholarly journals T-independent antigen induces humoral memory through germinal centers

2022 ◽  
Vol 219 (3) ◽  
Author(s):  
Xin Liu ◽  
Yongshan Zhao ◽  
Hai Qi
Keyword(s):  
B Cells ◽  
Immune Responses ◽  
Germinal Center ◽  
Plasma Cells ◽  
Underlying Mechanism ◽  
Memory B Cells ◽  
Antigen B ◽  
Per Se ◽  
Humoral Responses ◽  
Human And Mouse

T-dependent humoral responses generate long-lived memory B cells and plasma cells (PCs) predominantly through germinal center (GC) reaction. In human and mouse, memory B cells and long-lived PCs are also generated during immune responses to T-independent antigen, including bacterial polysaccharides, although the underlying mechanism for such T-independent humoral memory is not clear. While T-independent antigen can induce GCs, they are transient and thought to be nonproductive. Unexpectedly, by genetic fate-mapping, we find that these GCs actually output memory B cells and PCs. Using a conditional BCL6 deletion approach, we show memory B cells and PCs fail to last when T-independent GCs are precluded, suggesting that the GC experience per se is important for programming longevity of T-independent memory B cells and PCs. Consistent with the fact that infants cannot mount long-lived humoral memory to T-independent antigen, B cells from young animals intrinsically fail to form T-independent GCs. Our results suggest that T-independent GCs support humoral memory, and GC induction may be key to effective vaccines with T-independent antigen.

scholarly journals Immunosuppressive Mechanisms of Regulatory B Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Diego Catalán ◽  
Miguel Andrés Mansilla ◽  
Ashley Ferrier ◽  
Lilian Soto ◽  
Kristine Oleinika ◽  
...  
Keyword(s):  
B Cells ◽  
Immune Responses ◽  
Metabolic Diseases ◽  
Inflammatory Responses ◽  
Surface Proteins ◽  
Regulatory B Cells ◽  
Cell Surface Proteins ◽  
The Past ◽  
And Function

Regulatory B cells (Bregs) is a term that encompasses all B cells that act to suppress immune responses. Bregs contribute to the maintenance of tolerance, limiting ongoing immune responses and reestablishing immune homeostasis. The important role of Bregs in restraining the pathology associated with exacerbated inflammatory responses in autoimmunity and graft rejection has been consistently demonstrated, while more recent studies have suggested a role for this population in other immune-related conditions, such as infections, allergy, cancer, and chronic metabolic diseases. Initial studies identified IL-10 as the hallmark of Breg function; nevertheless, the past decade has seen the discovery of other molecules utilized by human and murine B cells to regulate immune responses. This new arsenal includes other anti-inflammatory cytokines such IL-35 and TGF-β, as well as cell surface proteins like CD1d and PD-L1. In this review, we examine the main suppressive mechanisms employed by these novel Breg populations. We also discuss recent evidence that helps to unravel previously unknown aspects of the phenotype, development, activation, and function of IL-10-producing Bregs, incorporating an overview on those questions that remain obscure.

scholarly journals The Normal Counterpart of IgD Myeloma Cells in Germinal Center Displays Extensively Mutated IgVH Gene, Cμ–Cδ Switch, and λ Light Chain Expression

1998 ◽  
Vol 187 (8) ◽  
pp. 1169-1178 ◽  
Author(s):  
Christophe Arpin ◽  
Odette de Bouteiller ◽  
Diane Razanajaona ◽  
Isabelle Fugier-Vivier ◽  
Francine Brière ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
Light Chain ◽  
Germinal Center ◽  
Plasma Cells ◽  
Precursor Cells ◽  
Memory B Cells ◽  
Hematopoietic Stem ◽  
Myeloma Cells ◽  
Λ Light Chain

Human myeloma are incurable hematologic cancers of immunoglobulin-secreting plasma cells in bone marrow. Although malignant plasma cells can be almost eradicated from the patient's bone marrow by chemotherapy, drug-resistant myeloma precursor cells persist in an apparently cryptic compartment. Controversy exists as to whether myeloma precursor cells are hematopoietic stem cells, pre–B cells, germinal center (GC) B cells, circulating memory cells, or plasma blasts. This situation reflects what has been a general problem in cancer research for years: how to compare a tumor with its normal counterpart. Although several studies have demonstrated somatically mutated immunoglobulin variable region genes in multiple myeloma, it is unclear if myeloma cells are derived from GCs or post-GC memory B cells. Immunoglobulin (Ig)D-secreting myeloma have two unique immunoglobulin features, including a biased λ light chain expression and a Cμ–Cδ isotype switch. Using surface markers, we have previously isolated a population of surface IgM−IgD+CD38+ GC B cells that carry the most impressive somatic mutation in their IgV genes. Here we show that this population of GC B cells displays the two molecular features of IgD-secreting myeloma cells: a biased λ light chain expression and a Cμ–Cδ isotype switch. The demonstration of these peculiar GC B cells to differentiate into IgD-secreting plasma cells but not memory B cells both in vivo and in vitro suggests that IgD-secreting plasma and myeloma cells are derived from GCs.

scholarly journals Antigen-Specific B Cell Memory

2000 ◽  
Vol 191 (7) ◽  
pp. 1149-1166 ◽  
Author(s):  
Louise J. McHeyzer-Williams ◽  
Melinda Cool ◽  
Michael G. McHeyzer-Williams
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Memory B Cells ◽  
Cell Memory ◽  
Specific Memory ◽  
B Cell Memory ◽  
Cellular Components

The mechanisms that regulate B cell memory and the rapid recall response to antigen remain poorly defined. This study focuses on the rapid expression of B cell memory upon antigen recall in vivo, and the replenishment of quiescent B cell memory that follows. Based on expression of CD138 and B220, we reveal a unique and major subtype of antigen-specific memory B cells (B220−CD138−) that are distinct from antibody-secreting B cells (B220+/−CD138+) and B220+CD138− memory B cells. These nonsecreting somatically mutated B220− memory responders rapidly dominate the splenic response and comprise >95% of antigen-specific memory B cells that migrate to the bone marrow. By day 42 after recall, the predominant quiescent memory B cell population in the spleen (75–85%) and the bone marrow (>95%) expresses the B220− phenotype. Upon adoptive transfer, B220− memory B cells proliferate to a lesser degree but produce greater amounts of antibody than their B220+ counterparts. The pattern of cellular differentiation after transfer indicates that B220− memory B cells act as stable self-replenishing intermediates that arise from B220+ memory B cells and produce antibody-secreting cells on rechallenge with antigen. Cell surface phenotype and Ig isotype expression divide the B220− compartment into two main subsets with distinct patterns of integrin and coreceptor expression. Thus, we identify new cellular components of B cell memory and propose a model for long-term protective immunity that is regulated by a complex balance of committed memory B cells with subspecialized immune function.

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