scholarly journals Chemokine Receptor-6 Promotes B-1 Cell Trafficking to Perivascular Adipose Tissue, Local IgM Production and Atheroprotection

2021 ◽  
Vol 12 ◽  
Author(s):  
Prasad Srikakulapu ◽  
Aditi Upadhye ◽  
Fabrizio Drago ◽  
Heather M. Perry ◽  
Sai Vineela Bontha ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
B Cells ◽  
B Cell ◽  
Chemokine Receptor ◽  
Immune Cell ◽  
Cell Number ◽  
Cell Trafficking ◽  
Perivascular Adipose Tissue ◽  
Major Mechanism ◽  
High Level

Chemokine receptor-6 (CCR6) mediates immune cell recruitment to inflammatory sites and has cell type-specific effects on diet-induced atherosclerosis in mice. Previously we showed that loss of CCR6 in B cells resulted in loss of B cell-mediated atheroprotection, although the B cell subtype mediating this effect was unknown. Perivascular adipose tissue (PVAT) harbors high numbers of B cells including atheroprotective IgM secreting B-1 cells. Production of IgM antibodies is a major mechanism whereby B-1 cells limit atherosclerosis development. Yet whether CCR6 regulates B-1 cell number and production of IgM in the PVAT is unknown. In this present study, flow cytometry experiments demonstrated that both B-1 and B-2 cells express CCR6, albeit at a higher frequency in B-2 cells in both humans and mice. Nevertheless, B-2 cell numbers in peritoneal cavity (PerC), spleen, bone marrow and PVAT were no different in ApoE−/−CCR6−/− compared to ApoE−/−CCR6+/+ mice. In contrast, the numbers of atheroprotective IgM secreting B-1 cells were significantly lower in the PVAT of ApoE−/−CCR6−/− compared to ApoE−/−CCR6+/+ mice. Surprisingly, adoptive transfer (AT) of CD43− splenic B cells into B cell-deficient μMT−/−ApoE−/− mice repopulated the PerC with B-1 and B-2 cells and reduced atherosclerosis when transferred into ApoE−/−CCR6+/+sIgM−/− mice only when those cells expressed both CCR6 and sIgM. CCR6 expression on circulating human B cells in subjects with a high level of atherosclerosis in their coronary arteries was lower only in the putative human B-1 cells. These results provide evidence that B-1 cell CCR6 expression enhances B-1 cell number and IgM secretion in PVAT to provide atheroprotection in mice and suggest potential human relevance to our murine findings.

Abstract 464: Chemokine Receptor CCR6 Expression on B Cells Augments Local IgM Production and Atheroprotection

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Prasad Srikakulapu ◽  
Chantel McSkimming ◽  
Coleen McNamara
Keyword(s):  
B Cells ◽  
B Cell ◽  
Adoptive Transfer ◽  
Chemokine Receptors ◽  
Immune Cell ◽  
Dependent Manner ◽  
Perivascular Adipose Tissue ◽  
Cell Recruitment ◽  
Cell Numbers ◽  
Atherosclerosis Development

Background: CCR6 mediates immune cell recruitment to inflammatory sites and has cell type-specific effects on diet-induced atherosclerosis in mice. Recent studies implicate the local immune responses in the adventitia/perivascular adipose tissue (PVAT) in atherosclerosis development. We have previously demonstrated that adoptive transfer of CD43 - splenocytes (B cells) into B cell deficient μMT -/- ApoE -/- mice results in reduced diet-induced atherosclerosis in a CCR6-dependent manner. Notably, there were significantly greater numbers of B cells in the aorta including PVAT of μMT -/- ApoE -/- mice which received splenic B cells from CCR6 +/+ mice compared to CCR6 -/- mice, despite no difference in B cell numbers in blood, spleen and peritoneal cavity, suggesting that CCR6 expression on B cells is important in B cell aortic homing. Production of IgM antibodies is thought to be a major mechanism whereby B cells limit atherosclerosis development. Yet whether B cells produce IgM locally in the PVAT and whether this is regulated by chemokine receptors such as CCR6 is unknown. Methods and Results: FACS experiments demonstrated high numbers of B cells available in the PVAT than aorta of young ApoE -/- (49121±11190 and 80±11; p<0.001, n=7) mice. ELISPOT experiments demonstrated significantly fewer IgM secreting cells were in the PVAT of ApoE -/- CCR6 -/- mice compared to ApoE -/- CCR6 +/+ mice (100±25 vs 850±150, p<0.05, n=5), despite no differences in IgM secreting cell numbers in spleen and bone marrow. Adoptive transfer of CD43 - splenic B cells from ApoE -/- CCR6 -/- and ApoE -/- CCR6 +/+ mice into secretory IgM deficient ApoE -/- sIgM -/- mice demonstrated significantly reduced atherosclerosis in mice that received B cells from ApoE -/- CCR6 +/+ mice compared to those that received B cells from ApoE -/- CCR6 -/- mice. Moreover, the B cells from ApoE -/- CCR6 +/+ mice attenuated atherosclerosis only when they were capable of secreting IgM. FACS data from human blood demonstrated that circulating B and T cells but not monocytes express CCR6, suggesting potential human relevance to our murine findings. Conclusion: Results provide evidence that CCR6 expression on B cells mediates B cell recruitment into aorta and/or PVAT to provide atheroprotection via IgM secretion.

scholarly journals Atypical chemokine receptor 4 shapes activated B cell fate

2018 ◽  
Vol 215 (3) ◽  
pp. 801-813 ◽  
Author(s):  
Ervin E. Kara ◽  
Cameron R. Bastow ◽  
Duncan R. McKenzie ◽  
Carly E. Gregor ◽  
Kevin A. Fenix ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Fate ◽  
Chemokine Receptor ◽  
Cell Trafficking ◽  
B Cell Differentiation ◽  
Cell Responses ◽  
Early Memory ◽  
Chemokine Receptor 4 ◽  
Activated B Cells

Activated B cells can initially differentiate into three functionally distinct fates—early plasmablasts (PBs), germinal center (GC) B cells, or early memory B cells—by mechanisms that remain poorly understood. Here, we identify atypical chemokine receptor 4 (ACKR4), a decoy receptor that binds and degrades CCR7 ligands CCL19/CCL21, as a regulator of early activated B cell differentiation. By restricting initial access to splenic interfollicular zones (IFZs), ACKR4 limits the early proliferation of activated B cells, reducing the numbers available for subsequent differentiation. Consequently, ACKR4 deficiency enhanced early PB and GC B cell responses in a CCL19/CCL21-dependent and B cell–intrinsic manner. Conversely, aberrant localization of ACKR4-deficient activated B cells to the IFZ was associated with their preferential commitment to the early PB linage. Our results reveal a regulatory mechanism of B cell trafficking via an atypical chemokine receptor that shapes activated B cell fate.

Abstract 293: Id3 Regulates High-Fat-Diet--Induced IgG2c Production

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Daniel B Harmon ◽  
Stephanie N Oldham ◽  
Loren D Erickson ◽  
Coleen A McNamara
Keyword(s):  
Adipose Tissue ◽  
B Cells ◽  
B Cell ◽  
High Fat Diet ◽  
Fold Increase ◽  
Cell Number ◽  
Metabolic Effects ◽  
High Fat ◽  
Helix Loop Helix

Background: High-fat diet (HFD)-induced adipose tissue inflammation leads to insulin resistance and glucose intolerance, increasing the risk of cardiovascular disease. Recently, B cells and IgG antibodies have been shown to promote the metabolic consequences of obesity. HFD induces IgG2c production - an IgG isotype that promotes inflammatory disorders. Mice null for Id3, a helix-loop-helix protein known to mediate IgG2c responses in vivo, develop significantly attenuated HFD-induced obesity; raising the interesting hypothesis that Id3 promotes HFD-induced obesity by mediating HFD-induced IgG2c production. Methods and results: Western Blot analysis revealed that primary splenic B cells stimulated with IFN + CD40L (an IgG2c-inducing cocktail) expressed significantly greater amounts of Id3 protein compared to B cells treated with CD40L alone ((1.26+/-0.05 vs 0.88+/-0.03; n=3; p=0.003). ELISA determination of immunoglobulin levels from whole adipose tissue of fed C57Bl/6J (WT) mice fed a HFD (60% kcal fat) revealed a 4 fold increase in IgG2c (3810+/-789 ng vs 993+/-422 ng; n=5; p=0.01) - but not IgM, IgG1, or IgG2b - compared to chow-fed controls. No differences in serum IgG2c were observed. In contrast, HFD-induced adipose tissue IgG2c levels were significantly attenuated in Id3 -/- mice (1643+/-493 vs 889+/-272 ng; n=6-7; p=0.19), despite the fact that Id3 -/- mice had significantly more adipose tissue B cells per (g) fat compared to WT (1.6E5+/-0.2E5 vs 0.5E5+/-0.09E5; n=5; p=0.001). Conclusions: Id3 promotes HFD-induced local adipose tissue IgG2c production; an effect not dependent on B cell number. Studies in animals with B cell-specific loss of Id3 are ongoing to identify the mechanisms whereby Id3 mediates HFD-induced IgG2c production and downstream metabolic effects.

scholarly journals POS1223 RAS GUANYL RELEASING PROTEIN 1 (RASGRP1) IN PERIPHERAL B CELLS LINKS RA TO COVID-19

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 895.2-895
Author(s):  
S. Hannawi ◽  
F. Alqutami ◽  
M. Y. Hachim
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Plasma Cells ◽  
Immune Cell ◽  
In Silico Analysis ◽  
Differentially Expressed ◽  
Transcriptional Enhancer ◽  
Activated T Cells

Background:Changes in the B cell subpopulations is a hallmark of the antiviral response against SARS-CoV-2 and is associated with COVID-19 severity (1). Recently our group showed common derangement observed in rheumatoid arthritis (RA) and COVID-19 (2). In RA, synovium attracts potentially autoreactive—B cells and plasma cells that play a central role in RA pathogenesis (3). We were interested to know the similarity in B cell’s transcriptomic changes specific to RA and COVID-19.Objectives:Identify similar upregulated genes in synovium and B cells in RA and at the same time are differentially expressed in B cells infected with SARS-CoV-2 or from COVID-19 patients.Methods:RNAseq dataset (GSE89408) of (218) samples isolated from joint synovial biopsies from subjects with and without rheumatoid arthritis were retrieved from GEO online database. Differentially expressed genes (DRGs) specific to RA were identified after exclusion of those upregulated in Osteoarthritis or other joint condition samples in the same dataset. The RA specific genes were intersected with DEGs between B cells from healthy versus RA as extracted from (GSE110999) dataset. The shortlisted genes specifically upregulated in B cells of RA were identified and were explored in B cells COVID-19 transcriptome datasets using (https://metascape.org/COVID).Results:60 genes were found to be specifically upregulated in RA synovium and B cells and are changed in B cells infected with SARS-CoV-2 or from COVID-19 patients, Figure (1-A). Those genes were involved in interferon signaling, antiviral and immune cell activation. RASGRP1 was common between B cells of RA and COVID-19 and might play a role in the pathogenesis of both, Figure (1-B). RASGRP1 controls ERK/MAPK kinase cascade needed in B-/T-cell differentiation and development. It is vital to protect against viral infection and the autoimmune associated proliferation of activated T-cells like RA (4). We checked its level in another dataset (GSE152641) of the whole blood RNASeq of 62 COVID-19 patients and 24 healthy controls. RASGRP1 was significantly down in COVID-19 compared to healthy control, Figure (1-C).Conclusion:SARS-CoV-2 impair B and T’s cells’ immune response through its action on RASGRP1 and that can be a novel mechanistic explanation of how the virus decreases immune cells and impair the B cell’s humoral immunity.References:[1]Sosa-Hernández VA, Torres-Ruíz J, Cervantes-Díaz R, Romero-Ramírez S, Páez-Franco JC, Meza-Sánchez DE, et al. B Cell Subsets as Severity-Associated Signatures in COVID-19 Patients. Frontiers in Immunology. 2020;11(3244).[2]Hachim MY, Hachim IY, Naeem KB, Hannawi H, Al Salmi I, Hannawi S. C-C chemokine receptor type 5 links COVID-19, rheumatoid arthritis, and Hydroxychloroquine: in silico analysis. Translational Medicine Communications. 2020;5(1):14.[3]Doorenspleet ME, Klarenbeek PL, de Hair MJ, van Schaik BD, Esveldt RE, van Kampen AH, et al. Rheumatoid arthritis synovial tissue harbours dominant B-cell and plasma-cell clones associated with autoreactivity. Ann Rheum Dis. 2014;73(4):756-62.[4]Molineros JE, Singh B, Terao C, Okada Y, Kaplan J, McDaniel B, et al. Mechanistic Characterization of RASGRP1 Variants Identifies an hnRNP-K-Regulated Transcriptional Enhancer Contributing to SLE Susceptibility. Frontiers in Immunology. 2019;10(1066).Disclosure of Interests:None declared

scholarly journals TP53INP1 deficiency maintains murine B lymphopoiesis in aged bone marrow through redox-controlled IL-7R/STAT5 signaling

2018 ◽  
Vol 116 (1) ◽  
pp. 211-216 ◽  
Author(s):  
Bochra Zidi ◽  
Christelle Vincent-Fabert ◽  
Laurent Pouyet ◽  
Marion Seillier ◽  
Amelle Vandevelde ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Immune Cell ◽  
B Lymphopoiesis ◽  
Hematopoietic Stem ◽  
Chronic Oxidative Stress ◽  
The Impact ◽  
Deficient Mice

Bone marrow (BM) produces all blood and immune cells deriving from hematopoietic stem cells (HSCs). The decrease of immune cell production during aging is one of the features of immunosenescence. The impact of redox dysregulation in BM aging is still poorly understood. Here we use TP53INP1-deficient (KO) mice endowed with chronic oxidative stress to assess the influence of aging-associated redox alterations in BM homeostasis. We show that TP53INP1 deletion has no impact on aging-related accumulation of HSCs. In contrast, the aging-related contraction of the lymphoid compartment is mitigated in TP53INP1 KO mice. B cells that accumulate in old KO BM are differentiating cells that can mature into functional B cells. Importantly, this phenotype results from B cell-intrinsic events associated with defective redox control. Finally, we show that oxidative stress in aged TP53INP1-deficient mice maintains STAT5 expression and activation in early B cells, driving high Pax5 expression, which provides a molecular mechanism for maintenance of B cell development upon aging.

scholarly journals B Lymphocytes and Adipose Tissue Inflammation

2020 ◽  
Vol 40 (5) ◽  
pp. 1110-1122 ◽  
Author(s):  
Prasad Srikakulapu ◽  
Coleen A. McNamara
Keyword(s):  
Adipose Tissue ◽  
B Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Metabolic Dysfunction ◽  
Adipose Tissue Inflammation ◽  
Cell Type ◽  
Tissue Inflammation ◽  
B Cell Subsets

The immune system plays an important role in obesity-induced adipose tissue inflammation and the resultant metabolic dysfunction, which can lead to hypertension, dyslipidemia, and insulin resistance and their downstream sequelae of type 2 diabetes mellitus and cardiovascular disease. While macrophages are the most abundant immune cell type in adipose tissue, other immune cells are also present, such as B cells, which play important roles in regulating adipose tissue inflammation. This brief review will overview B-cell subsets, describe their localization in various adipose depots and summarize our knowledge about the function of these B-cell subsets in regulating adipose tissue inflammation, obesity-induced metabolic dysfunction and atherosclerosis.

Regulation of CCR6 chemokine receptor expression and responsiveness to macrophage inflammatory protein-3α/CCL20 in human B cells

Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2338-2345 ◽  
Author(s):  
Roman Krzysiek ◽  
Eric A. Lefevre ◽  
Jérôme Bernard ◽  
Arnaud Foussat ◽  
Pierre Galanaud ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Chemokine Receptor ◽  
Memory B Cells ◽  
Receptor Expression ◽  
B Cell Differentiation ◽  
Hematopoietic Stem ◽  
Inflammatory Protein ◽  
Macrophage Inflammatory Protein

Abstract The regulation of CCR6 (chemokine receptor 6) expression during B-cell ontogeny and antigen-driven B-cell differentiation was analyzed. None of the CD34+Lin− hematopoietic stem cell progenitors or the CD34+CD19+ (pro-B) or the CD19+CD10+ (pre-B/immature B cells) B-cell progenitors expressed CCR6. CCR6 is acquired when CD10 is lost and B-cell progeny matures, entering into the surface immunoglobulin D+ (sIgD+) mature B-cell pool. CCR6 is expressed by all bone marrow–, umbilical cord blood–, and peripheral blood–derived naive and/or memory B cells but is absent from germinal center (GC) B cells of secondary lymphoid organs. CCR6 is down-regulated after B-cell antigen receptor triggering and remains absent during differentiation into immunoglobulin-secreting plasma cells, whereas it is reacquired at the stage of post-GC memory B cells. Thus, within the B-cell compartment, CCR6 expression is restricted to functionally mature cells capable of responding to antigen challenge. In transmigration chemotactic assays, macrophage inflammatory protein (MIP)-3α/CC chemokine ligand 20 (CCL20) induced vigorous migration of B cells with differential chemotactic preference toward sIgD− memory B cells. These data suggest that restricted patterns of CCR6 expression and MIP-3α/CCL20 responsiveness are integral parts of the process of B-lineage maturation and antigen-driven B-cell differentiation.

scholarly journals Growth- and differentiation-associated expression of bcl-2 in B-chronic lymphocytic leukemia cells

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2981-2989 ◽  
Author(s):  
M Schena ◽  
LG Larsson ◽  
D Gottardi ◽  
G Gaidano ◽  
M Carlsson ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Messenger Rna ◽  
Phorbol Esters ◽  
Lymphocytic Leukemia ◽  
Mantle Zone ◽  
Cell Stage ◽  
High Level

Abstract The bcl-2 gene is translocated into the Ig loci in about 80% of human follicular lymphomas and in 10% of B-type chronic lymphocytic leukemias (B-CLL), resulting in a high level of expression. We have compared the expression of bcl-2 transcripts and protein in B-CLL cells in their normal equivalent CD5+ B cells and in normal B-cell populations representative of different in vivo and in vitro stages of activation and proliferation. We report here that bcl-2 was expressed in 11 of 11 cases of CD5+ B-CLL clones, contrasting with the absent expression in normal CD5+ B cells. Activation of 173 and 183 B-CLL cells by phorbol esters (12-O-tetradecanoylphorbol-13-acetate [TPA]) to IgM secretion without concomitant DNA synthesis resulted in a rapid but transient downregulation of bcl-2 expression. In contrast, the reduction of bcl-2 at both the messenger RNA and protein levels was sustained after mitogenic stimulation, suggesting that bcl-2 expression and proliferation are inversely related in these cells. This notion was further supported by immunocytochemical analysis showing that bcl-2 was primarily expressed in small resting lymphocytes and in cells differentiating to the plasma cell stage, but less expressed in Ki67- positive proliferating B blasts. Moreover, it was also supported by the low level of bcl-2 in exponentially growing Epstein-Barr virus-carrying lymphoblastoid and B-CLL cell lines. The regulation of bcl-2 expression in B-CLL resembled that of normal tonsillar follicular B cells, in which a high level of expression was found in resting mantle zone B cells but not in the proliferating germinal center B cells. Based on these findings and the role of bcl-2 in maintaining B-cell memory, we propose that the phenotype of B-CLL cells corresponds to a mantle zone memory-type B cell.

Evidence for B cell maturation but not trained immunity in uninfected infants exposed to hepatitis C virus

Gut ◽  
2020 ◽  
Vol 69 (12) ◽  
pp. 2203-2213 ◽  
Author(s):  
Anton Lutckii ◽  
Benedikt Strunz ◽  
Anton Zhirkov ◽  
Olga Filipovich ◽  
Elena Rukoiatkina ◽  
...  
Keyword(s):  
Immune System ◽  
B Cells ◽  
B Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Innate Immune ◽  
Cell Maturation ◽  
Innate Immune Cells ◽  
B Cell Maturation ◽  
Exposed Uninfected

ObjectivesVertical transmission of hepatitis C virus (HCV) is rare compared with other chronic viral infections, despite that newborns have an immature, and possibly more susceptible, immune system. It further remains unclear to what extent prenatal and perinatal exposure to HCV affects immune system development in neonates.DesignTo address this, we studied B cells, innate immune cells and soluble factors in a cohort of 62 children that were either unexposed, exposed uninfected or infected with HCV. Forty of these infants were followed longitudinally from birth up until 18 months of age.ResultsAs expected, evidence for B cell maturation was observed with increased age in children, whereas few age-related changes were noticed among innate immune cells. HCV-infected children had a high frequency of HCV-specific IgG-secreting B cells. Such a response was also detected in some exposed but uninfected children but not in uninfected controls. Consistent with this, both HCV-exposed uninfected and HCV-infected infants had evidence of early B cell immune maturation with an increased proportion of IgA-positive plasma cells and upregulated CD40 expression. In contrast, actual HCV viraemia, but not mere exposure, led to alterations within myeloid immune cell populations, natural killer (NK) cells and a distinct soluble factor profile with increased levels of inflammatory cytokines and chemokines.ConclusionOur data reveal that exposure to, and infection with, HCV causes disparate effects on adaptive B cells and innate immune cell such as myeloid cells and NK cells in infants.

Human mesenchymal stem cells modulate B-cell functions

Blood ◽  
2006 ◽  
Vol 107 (1) ◽  
pp. 367-372 ◽  
Author(s):  
Anna Corcione ◽  
Federica Benvenuto ◽  
Elisa Ferretti ◽  
Debora Giunti ◽  
Valentina Cappiello ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
B Cells ◽  
B Cell ◽  
Cell Function ◽  
Costimulatory Molecule ◽  
Human Mesenchymal Stem Cells ◽  
B Cell Differentiation ◽  
Major Mechanism ◽  
Cell Functions

Abstract Human mesenchymal stem cells (hMSCs) suppress T-cell and dendritic-cell function and represent a promising strategy for cell therapy of autoimmune diseases. Nevertheless, no information is currently available on the effects of hMSCs on B cells, which may have a large impact on the clinical use of these cells. hMSCs isolated from the bone marrow and B cells purified from the peripheral blood of healthy donors were cocultured with different B-cell tropic stimuli. B-cell proliferation was inhibited by hMSCs through an arrest in the G0/G1 phase of the cell cycle and not through the induction of apoptosis. A major mechanism of B-cell suppression was hMSC production of soluble factors, as indicated by transwell experiments. hMSCs inhibited B-cell differentiation because IgM, IgG, and IgA production was significantly impaired. CXCR4, CXCR5, and CCR7 B-cell expression, as well as chemotaxis to CXCL12, the CXCR4 ligand, and CXCL13, the CXCR5 ligand, were significantly down-regulated by hMSCs, suggesting that these cells affect chemotactic properties of B cells. B-cell costimulatory molecule expression and cytokine production were unaffected by hMSCs. These results further support the potential therapeutic use of hMSCs in immune-mediated disorders, including those in which B cells play a major role.

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