NMDA-receptor antagonists block B-cell function but foster IL-10 production in BCR/CD40-activated B cells

In the present study, we examined the expression of interleukin 2 (IL-2) receptors on normal human B cells as well as established B cell lines. Anti-Tac monoclonal antibody did not bind to freshly separated normal human B cells. Unexpectedly, with the appropriate activation of the normal B cells by anti-mu antibody, phorbol myristate acetate, or Staphylococcus aureus Cowan I (SAC), Tac antigen was induced on the activated B cells. Anti-Tac antibody showed consistent reactivity with two B cell lines that were infected by human T cell leukemia virus (HTLV) and some reactivity with two out of eight Epstein-Barr virus-transformed B cell lines established from normal adult donors. Immunoprecipitation analysis revealed that antigens of similar size with a molecular weight of 50,000-60,000 can be precipitated with anti-Tac antibody from phytohemagglutinin-stimulated normal T cell blasts and normal activated B cells, as well as a cloned B cell line. Binding assays of IL-2 on normal activated B cells and on the cloned B cell (HS1) revealed that B cells have significantly fewer sites and lower-affinity IL-2 receptors compared with phytohemagglutinin-stimulated normal T cell blasts. Finally, biological properties of the IL-2 receptor on B cells were examined by incubating B cells with recombinant IL-2. It was found that moderate concentrations of IL-2 induce significant enhancement of proliferation and differentiation in SAC-activated normal B cells. These results suggest that normal B cells may express functional IL-2 receptors or closely related proteins and thus IL-2 may play a significant role in the modulation of B cell function.

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B cell-specific GPR55 deficiency promotes atherosclerosis

European Heart Journal ◽

10.1093/ehjci/ehaa946.3785 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

R Guillamat-Prats ◽

D Hering ◽

M Rami ◽

C Haerdtner ◽

L Bindila ◽

...

Keyword(s):

Body Weight ◽

B Cells ◽

B Cell ◽

Mrna Expression ◽

Cell Function ◽

Metabolic Effects ◽

Atherosclerotic Plaques ◽

Funding Source ◽

Sequencing Analysis ◽

B Cell Function

Abstract Background Atherosclerosis is accompanied by an imbalance between resolving and pro-inflammatory lipid mediators. Targeting lipid signaling pathways might offer a new anti-inflammatory therapy for improving the clinical outcome in cardiovascular disease patients. We considered lysophosphatidylinositol (LPI) and its receptor G protein-coupled receptor (GPR)55 as a potential modulator of atherosclerosis. Its role in regulating atherosclerosis and B cell function is unknown. Hypothesis We assessed the hypothesis that GPR55 signaling causally affects atherosclerosis and whether it has a specific role in regulating B cell function in this disease. Methods Atherosclerotic plaques were compared between apolipoprotein E deficient (ApoE−/−) and ApoE−/−Gpr55−/− mice after 4 to 16 weeks Western Diet (WD; 0.15% cholesterol; n=12–15 per group). To specifically test the role of B cell GPR55 in atherosclerosis, we generated mixed chimeras by lethally irradiating low density lipoprotein receptor deficient (Ldlr−/−) mice and reconstituting with a mixture of μMT and wildtype (control) or μMT and Gpr55−/− bone marrow cells. Circulating B cells were sorted and bulk RNA sequencing analysis was performed. We performed lipid and immunostainings of murine aortic root plaques, qPCR and ELISA of tissue lysates, as well as multiplex analysis of plasma immunoglobulins. Leukocyte plasma and tissue counts were determined by flow cytometry. Results GPR55 expression in mouse and human atherosclerotic plaques was detected by immunostaining. Furthermore, we confirmed murine Gpr55 mRNA expression on sorted circulating B220+B cells via qPCR, which was higher compared to CD3+ T cells, while CD11+ myeloid cells as well as NK cells had only low Gpr55 mRNA levels. ApoE−/−Gpr55−/− mice had significantly larger plaques after 4&16 weeks WD compared to ApoE−/− controls, with more pronounced body weight increases and higher cholesterol levels at the 16 weeks WD time point. In addition, global Gpr55 deficiency resulted in enhanced aortic pro-inflammatory cytokine mRNA expression (IL-1β, IL-6, TNFα) and a massively upregulated IgG1 plasma levels and increased percentages of splenic germinal center and plasma cells. B-cell RNA-seq analysis showed 460 differential expressed regulated genes in the ApoE−/−Gpr55−/− compared to ApoE−/−. The main pathways affected were calcium ion transport, immunoglobulin production, negative regulation of phosphorylation, and cellular component morphogenesis, suggesting a dsysregulation of B cell function. B cell specific Gpr55 deficiency blunted the metabolic effects on body weight and cholesterol, but still translated in larger atherosclerotic plaques and elevated plasma IgG levels compared to the respective controls. Conclusion Both global and B cell-restricted Gpr55 deficiency promotes atherosclerosis and is associated with a more pro-inflammatory phenotype. Our findings suggest a novel role for GPR55 in regulating B cell development and function. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG)

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Engagement of CD83 on B Cells Modulates B Cell Function In Vivo

The Journal of Immunology ◽

10.4049/jimmunol.0803153 ◽

2009 ◽

Vol 182 (5) ◽

pp. 2827-2834 ◽

Cited By ~ 21

Author(s):

Birte Kretschmer ◽

Katja Lüthje ◽

Stefanie Schneider ◽

Bernhard Fleischer ◽

Minka Breloer

Keyword(s):

B Cells ◽

B Cell ◽

Cell Function ◽

B Cell Function

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In vitro regulation of immunoglobulin synthesis after marrow transplantation. I. T-cell and B-cell deficiencies in patients with and without chronic graft-versus-host disease

Blood ◽

10.1182/blood.v58.3.431.431 ◽

1981 ◽

Vol 58 (3) ◽

pp. 431-439 ◽

Cited By ~ 65

Author(s):

LG Lum ◽

MC Seigneuret ◽

RF Storb ◽

RP Witherspoon ◽

ED Thomas

Keyword(s):

T Cell ◽

B Cells ◽

B Cell ◽

Graft Versus Host Disease ◽

Marrow Transplantation ◽

Cell Function ◽

Cell Activity ◽

Graft Versus Host ◽

B Cell Function

Abstract Twenty-four patients with aplastic anemia or acute leukemia were treated by marrow grafts from HLA-identical donors after conditioning with high doses of cyclophosphamide and/or today body irradiation. They were studied between 4 and 63 mo (median 14.2) after transplantation. Seventeen patients had chronic graft-versus-host disease (C-GVHD) and 7 were healthy. They were studied for defects in their T- and B-cell function using and indirect hemolytic plaque assay for Ig production after 6 days of culture in the presence of pokeweek mitogen. T or B cells from the patients with or without C-GVHD were cocultured with T or B cells from their HLA-identical marrow donors or unrelated normal controls. Intrinsic B-cell defects, lack of helper T-cell activity, and suppressor T-cell activity were more frequently found in patients with C-GVHD than in healthy patients. Fifteen of the 17 patients with C-GVHD showed on or more defects in their T-and B-cell function compared to only 3 of the 7 patients without C-GVHD. None of the healthy controls, including the marrow donors, showed defects in their T- and B-cell functions. These in vitro findings may be helpful in assessing the process of immune reconstitution and the immunologic aberration found after human marrow transplantation.

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Long-Term Chimerism and B-Cell Function After Bone Marrow Transplantation in Patients With Severe Combined Immunodeficiency With B Cells: A Single-Center Study of 22 Patients

Blood ◽

10.1182/blood.v94.8.2923.420k44_2923_2930 ◽

1999 ◽

Vol 94 (8) ◽

pp. 2923-2930 ◽

Cited By ~ 97

Author(s):

Elie Haddad ◽

Françoise Le Deist ◽

Pierre Aucouturier ◽

Marina Cavazzana-Calvo ◽

Stephane Blanche ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

Bone Marrow Transplantation ◽

B Cells ◽

B Cell ◽

Cell Function ◽

Severe Combined Immunodeficiency ◽

Combined Immunodeficiency ◽

B Cell Function ◽

Host Origin

We retrospectively analyzed the B-cell function and leukocyte chimerism of 22 patients with severe combined immunodeficiency with B cells (B+ SCID) who survived more than 2 years after bone marrow transplantation (BMT) to determine the possible consequences of BMT procedures, leukocyte chimerism, and SCID molecular deficit on B-cell function outcome. Circulating T cells were of donor origin in all patients. In recipients of HLA-identical BMT (n = 5), monocytes were of host origin in 5 and B cells were of host origin in 4 and of mixed origin in 1. In recipients of HLA haploidentical T-cell–depleted BMT (n = 17), B cells and monocytes were of host origin in 14 and of donor origin in 3. Engraftment of B cells was found to be associated with normal B-cell function. In contrast, 10 of 18 patients with host B cells still require Ig substitution. Conditioning regimen (ie, 8 mg/kg busulfan and 200 mg/kg cyclophosphamide) was shown neither to promote B-cell and monocyte engraftment nor to affect B-cell function. Eight patients with B cells of host origin had normal B-cell function. Evidence for functional host B cells was further provided in 3 informative cases by Ig allotype determination and by the detection, in 5 studied cases, of host CD27+ memory B cells as in age-matched controls. These results strongly suggest that, in some transplanted patients, host B cells can cooperate with donor T cells to fully mature in Ig-producing cells.

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Restriction of blood and marrow CLL-B cells to free L-chain IG secretion: Implication for normal B-cell function and control

American Journal of Hematology ◽

10.1002/ajh.2830290302 ◽

1988 ◽

Vol 29 (3) ◽

pp. 125-133 ◽

Cited By ~ 3

Author(s):

John E. Hopper ◽

Jamie O'brien ◽

Elaine Papagiannes

Keyword(s):

B Cells ◽

B Cell ◽

Cell Function ◽

B Cell Function ◽

And Control

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In vitro regulation of immunoglobulin synthesis after marrow transplantation. I. T-cell and B-cell deficiencies in patients with and without chronic graft-versus-host disease

Blood ◽

10.1182/blood.v58.3.431.bloodjournal583431 ◽

1981 ◽

Vol 58 (3) ◽

pp. 431-439 ◽

Cited By ~ 1

Author(s):

LG Lum ◽

MC Seigneuret ◽

RF Storb ◽

RP Witherspoon ◽

ED Thomas

Keyword(s):

T Cell ◽

B Cells ◽

B Cell ◽

Graft Versus Host Disease ◽

Marrow Transplantation ◽

Cell Function ◽

Cell Activity ◽

Graft Versus Host ◽

B Cell Function

Twenty-four patients with aplastic anemia or acute leukemia were treated by marrow grafts from HLA-identical donors after conditioning with high doses of cyclophosphamide and/or today body irradiation. They were studied between 4 and 63 mo (median 14.2) after transplantation. Seventeen patients had chronic graft-versus-host disease (C-GVHD) and 7 were healthy. They were studied for defects in their T- and B-cell function using and indirect hemolytic plaque assay for Ig production after 6 days of culture in the presence of pokeweek mitogen. T or B cells from the patients with or without C-GVHD were cocultured with T or B cells from their HLA-identical marrow donors or unrelated normal controls. Intrinsic B-cell defects, lack of helper T-cell activity, and suppressor T-cell activity were more frequently found in patients with C-GVHD than in healthy patients. Fifteen of the 17 patients with C-GVHD showed on or more defects in their T-and B-cell function compared to only 3 of the 7 patients without C-GVHD. None of the healthy controls, including the marrow donors, showed defects in their T- and B-cell functions. These in vitro findings may be helpful in assessing the process of immune reconstitution and the immunologic aberration found after human marrow transplantation.

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CD4+ T Cell Dependent B Cell Recovery and Function After Autologous Hematopoietic Stem Cell Transplantation

Frontiers in Immunology ◽

10.3389/fimmu.2021.736137 ◽

2021 ◽

Vol 12 ◽

Author(s):

Clarissa Heck ◽

Sophie Steiner ◽

Eva M. Kaebisch ◽

Marco Frentsch ◽

Friedrich Wittenbecher ◽

...

Keyword(s):

T Cell ◽

B Cells ◽

B Cell ◽

Cell Function ◽

High Dose Chemotherapy ◽

Cd4 T Cell ◽

High Dose ◽

Hematopoietic Stem ◽

B Cell Function ◽

Proliferation And Differentiation

IntroductionHigh-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) represents a standard treatment regime for multiple myeloma (MM) patients. Common and potentially fatal side effects after auto-HSCT are infections due to a severely compromised immune system with hampered humoral and cellular immunity. This study delineates in depth the quantitative and functional B cell defects and investigates underlying extrinsic or intrinsic drivers.MethodsPeripheral blood of MM patients undergoing high-dose chemotherapy and auto-HSCT (before high-dose chemotherapy and in early reconstitution after HSCT) was studied. Absolute numbers and distribution of B cell subsets were analyzed ex vivo using flow cytometry. Additionally, B cell function was assessed with T cell dependent (TD) and T cell independent (TI) stimulation assays, analyzing proliferation and differentiation of B cells by flow cytometry and numbers of immunoglobulin secreting cells in ELISpots.ResultsQuantitative B cell defects including a shift in the B cell subset distribution occurred after auto-HSCT. Functionally, these patients showed an impaired TD as well as TI B cell immune response. Individual functional responses correlated with quantitative alterations of CD19+, CD4+, memory B cells and marginal zone-like B cells. The TD B cell function could be partially restored upon stimulation with CD40L/IL-21, successfully inducing B cell proliferation and differentiation into plasmablasts and immunoglobulin secreting cells.ConclusionQuantitative and functional B cell defects contribute to the compromised immune defense in MM patients undergoing auto-HSCT. Functional recovery upon TD stimulation and correlation with CD4+ T cell numbers, indicate these as extrinsic drivers of the functional B cell defect. Observed correlations of CD4+, CD19+, memory B and MZ-like B cell numbers with the B cell function suggest that these markers should be tested as potential biomarkers in prospective studies.

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Defining Fundamental B Cell-Subset Dysfunction in Myeloma

Blood ◽

10.1182/blood.v128.22.2085.2085 ◽

2016 ◽

Vol 128 (22) ◽

pp. 2085-2085

Author(s):

Rao H Prabhala ◽

Srikanth Talluri ◽

Megan Stekla ◽

Andreea Negroiu ◽

Michael Buonopane ◽

...

Keyword(s):

T Cells ◽

B Cells ◽

B Cell ◽

Cell Function ◽

Memory T Cells ◽

Cell Subset ◽

Cell Dysfunction ◽

B Cell Function ◽

Ifn Γ ◽

B Cell Subsets

Abstract One of the most prominent features of multiple myeloma (MM) has been immune deficiency which predisposes patients to infectious complications and suppresses development of anti-MM immune responses. We and others have previously described the T cell dysfunction in Th1, Treg and Th17 cells, plasmacytoid dendritic cells and myeloid-derived suppressor cells (MDSC). However, the most fundamental and long identified deficiency is in the humoral immune response. Suppression of uninvolved immunoglobulins (UIgs) have been well described (i.e. suppression of serum IgA and IgM in IgG myeloma); and antibody responses to vaccination have been inadequate. However, very limited information is available regarding B cell function and how UIgs are suppressed in myeloma. We have now evaluated six different B cell subsets (B1a, B1b, B2, Breg, IRA-B, and MZ) in peripheral blood (PBMC) and bone marrow (BM) to understand alterations in B cell immune function in MM. We have observed significantly lower ratio of B2 (normal B cell-subset) and B1a (natural antibody-producing cells) subsets (10±4 vs 57±17; p < 0.05) and B2 and Breg (regulatory B cell-subset) subsets (14±4 vs 45±13; p< 0.05) in PBMC from MM patients (N=19) compared with healthy donor (N=33) respectively. Similar results were observed in BM samples from MM patients (N=18) compared with healthy donors (N=12); B2/B1a subset (2.4±0.6 vs 8±1.3; p < 0.05) and B2/Breg subset (8±1.4 vs 43.7±8.4; p< 0.05) respectively. To understand whether MM cells directly or indirectly alter B cell-subsets, we incubated myeloma cells (N=4) with healthy donor PBMCs, and analyzed B cell subsets after 3 days. We observed significant elevation in B1 subset (2.5 fold of control) and reduced B2 subset (89±3% of control). When we incubated PBMCs with IL-17A over-expressing MM cells (N=3), we observed further significant reduction in B2 subset (74% of control). When normal PBMCs are cultured in IL-17A (N=4) we observed significantly increased IL-10-producing Breg subset (28% of control). Similarly, co-culture of healthy B cells with MDSC led to significant increase (3.8 times) in Breg cell- population (N=3) compared with control group. To study the impact of B cell dysfunction on T cell function in MM, we activated normal PBMC via anti-CD3 antibody, in the presence or absence of B cells, and measured intra-cellular IFN-γ levels in CD69+ cells. We observed that the absence of B cells significantly inhibited interferon-producing T cells compared to control (by 43%; p<0.05). Importantly, following removal of CD25+ cells (Tregs and activated memory T cells), with or without B cells, we did not observe any difference in the inhibition of IFN-γ, indicating that B cells influence memory T cells rather than naïve T cells for the production of IFN-γ. To evaluate impact of lenalidomide on this interaction, we stimulated purified normal donor CD45RO memory T cells with Th1 polarizing cocktail in the presence or absence of purified normal B cells or B cells from MM patient (MM-B) in presence of lenalidomide and observed thatlenalidomide significantly improved MM-B cell-mediated IFN-γ-producing Th1 responses (by 32%, p<0.05) compared to normal B cell-mediated Th1 responses. In an effort to evaluate whether any therapy may improve the B cell function, we cultured normal PBMCs in the presence of lenalidomide (N=9) and observed reduction in Breg subset by 40% of control. To evaluate the effect of therapy on B cell-subsets in MM, we analyzed B cell subsets in PBMC from newly-diagnosed and lenalidomide-treated MM patients and observed that lenalidomide-treated group showed significant (p<0.05) improvement in B cell subsets (increased B2 and lower B1 cells) even before clinical response. These results suggest that immunomodulatory agents may be able to re-program humoral immunity in these patients. In summary, we report that the myeloma cell driven skewed B cell subset distribution with consequent B cell dysfunction drives the observed abnormalities in humoral/cell mediated immunity. The current therapeutic interventions, besides providing deep clinical responses, may also improve B cell function with impact on long term outcome. Disclosures No relevant conflicts of interest to declare.

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