Humoral immune deficiency in multiple myeloma patients due to compromised B-cell function

Abstract Sex steroids, such as estrogens and androgens, are important regulators of the humoral immune response. Studies in female mice have demonstrated that alteration of circulating estrogen concentration regulates antibody-mediated immunity. As males have normally little endogenous estrogen, we hypothesized that in males high estrogens and low androgens affect the immune system and enhance the allergic inflammatory response. Here, we studied transgenic male mice expressing human aromatase (AROM+). These animals have a high circulating estrogen to androgen ratio (E/A), causing female traits such as gynecomastia. We found that AROM+ male mice had significantly higher plasma immunoglobulin levels, particularly IgE. Flow cytometry analyses of splenocytes revealed changes in mature/immature B cell ratio together with a transcriptional upregulation of the Igh locus. Furthermore, higher proliferation rate and increased IgE synthesis after IgE class-switching was found. Subsequently, we utilized an ovalbumin airway challenge model to test the allergic response in AROM+ male mice. In line with above observations, an increase in IgE levels was measured, albeit no impact on immune cell infiltration into the lungs was detected. Together, our findings suggest that high circulating E/A in males significantly alters B cell function without any significant enhancement in allergic inflammation.

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Deficiencies of Innate and Adaptive Immunity

10.2310/im.1066 ◽

2013 ◽

Author(s):

Kathleen E Sullivan ◽

Soma Jyonouchi

Keyword(s):

Immune Deficiency ◽

Innate Immunity ◽

T Cell ◽

B Cell ◽

Signaling Pathway ◽

Interferon Gamma ◽

Cell Function ◽

Tlr Signaling ◽

Immunoglobulin Production ◽

B Cell Function

Defects in B cell function, T cell function, and innate immunity comprise the majority of primary immune deficiencies. Each compartment has a characteristic set of archetypical features. Defects in B cell function are characterized by poor immunoglobulin production, which, in turn, leads to recurrent sinopulmonary infections. Defects in T cell function are characterized by delayed clearance of viruses, susceptibility to opportunistic infections, and a high rate of autoimmune disease. Defects of innate immunity are typically associated with early-onset, severe infections. This chapter describes defects in immunoglobulin production or function, T cell disorders, defects in Toll-like receptor (TLR) signaling, defects in the interleukin-12 (IL-12)/interferon-gamma signaling pathway, and defects of T helper type 17 (Th17) immunity. Tables outline specific pathogens that should alert the clinician to potential immune deficiency, provide a comparison of immunoglobulin production defects, and describe severe combined immune deficiency types. Figures include schematic representations of the TLR signaling pathway, the IL-12/interferon-gamma signaling pathway, and the Th17 immune response. This chapter contains 3 highly rendered figures, 3 tables, 72 references, and 5 MCQs.

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Enhancement of thymopoiesis after bone marrow transplant by in vivo interleukin-7

Blood ◽

10.1182/blood.v88.5.1887.1887 ◽

1996 ◽

Vol 88 (5) ◽

pp. 1887-1894 ◽

Cited By ~ 177

Author(s):

E Bolotin ◽

M Smogorzewska ◽

S Smith ◽

M Widmer ◽

K Weinberg

Keyword(s):

Immune Deficiency ◽

Bone Marrow ◽

T Lymphocytes ◽

B Cell ◽

Cell Function ◽

Normal Numbers ◽

B Cell Function ◽

Interleukin 7 ◽

Immature Thymocytes

Abstract Bone marrow transplantation (BMT) is followed by a period of profound immune deficiency, during which new T lymphocytes are generated from either stem cells or immature thymic progenitors. Interleukin-7 (IL-7) induces proliferation and differentiation of immature thymocytes. We examined whether the in vivo administration of IL-7 to mice receiving BMT would alter thymic reconstitution. Lethally irradiated C57BL/6 mice received syngeneic BMT, followed by either IL-7 or placebo from days 5 to 18 post-BMT. At day 28, BMT recipients that had not received IL-7 had profound thymic hypoplasia (< 5% of normal), with relative increases in the numbers of immature thymocytes, decreased numbers of mature peripheral (splenic) T lymphocytes, and severely impaired T- and B-cell function. In contrast, transplanted mice treated with IL-7 had normalization of thymic cellularity, with normal proportions of thymic subsets and T-cell receptor beta variable gene (TCRV beta) usage, normal numbers of peripheral CD4+ T lymphocytes, and improved antigen- specific T- and B-cell function. In the BMT-IL-7 mice, there was an eightfold increase in the number of immature CD3-CD4-CD8- thymocytes in G2-M of the cell cycle, indicating that restoration of thymic cellularity was due to enhanced proliferation of immature thymic progenitors. Similar effects following IL-7 administration were also observed when donor bone marrow was depleted of mature T lymphocytes, indicating that IL-7 administration affected immature hematopoietic progenitors. IL-7 promotes thymic reconstitution after BMT, and may be useful in preventing post-BMT immune deficiency.

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Enhancement of thymopoiesis after bone marrow transplant by in vivo interleukin-7

Blood ◽

10.1182/blood.v88.5.1887.bloodjournal8851887 ◽

1996 ◽

Vol 88 (5) ◽

pp. 1887-1894 ◽

Cited By ~ 5

Author(s):

E Bolotin ◽

M Smogorzewska ◽

S Smith ◽

M Widmer ◽

K Weinberg

Keyword(s):

Immune Deficiency ◽

Bone Marrow ◽

T Lymphocytes ◽

B Cell ◽

Cell Function ◽

Normal Numbers ◽

B Cell Function ◽

Interleukin 7 ◽

Immature Thymocytes

Bone marrow transplantation (BMT) is followed by a period of profound immune deficiency, during which new T lymphocytes are generated from either stem cells or immature thymic progenitors. Interleukin-7 (IL-7) induces proliferation and differentiation of immature thymocytes. We examined whether the in vivo administration of IL-7 to mice receiving BMT would alter thymic reconstitution. Lethally irradiated C57BL/6 mice received syngeneic BMT, followed by either IL-7 or placebo from days 5 to 18 post-BMT. At day 28, BMT recipients that had not received IL-7 had profound thymic hypoplasia (< 5% of normal), with relative increases in the numbers of immature thymocytes, decreased numbers of mature peripheral (splenic) T lymphocytes, and severely impaired T- and B-cell function. In contrast, transplanted mice treated with IL-7 had normalization of thymic cellularity, with normal proportions of thymic subsets and T-cell receptor beta variable gene (TCRV beta) usage, normal numbers of peripheral CD4+ T lymphocytes, and improved antigen- specific T- and B-cell function. In the BMT-IL-7 mice, there was an eightfold increase in the number of immature CD3-CD4-CD8- thymocytes in G2-M of the cell cycle, indicating that restoration of thymic cellularity was due to enhanced proliferation of immature thymic progenitors. Similar effects following IL-7 administration were also observed when donor bone marrow was depleted of mature T lymphocytes, indicating that IL-7 administration affected immature hematopoietic progenitors. IL-7 promotes thymic reconstitution after BMT, and may be useful in preventing post-BMT immune deficiency.

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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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