scholarly journals Impact of deranged B cell subsets distribution in the development of HCV-related cirrhosis and HCC in type two diabetes mellitus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fadwa A. Abdelwahab ◽  
Khaled M. Hassanein ◽  
Helal F. Hetta ◽  
Mohamed O. Abdelmalek ◽  
Asmaa M. Zahran ◽  
...  
Keyword(s):  
Liver Disease ◽  
Hepatitis C ◽  
B Cells ◽  
B Cell ◽  
Disease Progression ◽  
Memory B Cells ◽  
Diabetic Patients ◽  
Transitional B Cells ◽  
Liver Disease Progression ◽  
B Cell Subsets

AbstractType II diabetes (T2D) may worsen the course of hepatitis C virus infection with a greater risk of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). In chronic viral infections, the deranged B cell subset signifies uncontrolled disease. The study aimed to verify the relation between B cell subsets’ distribution and liver disease progression in chronic hepatitis C (CHC) patients with T2D. A total of 67 CHC patients were divided into two groups; 33 non-diabetic and 34 with T2D. Each group was subdivided into CHC-without LC or HCC (N-CHC), CHC-with LC (CHC-LC), and CHC-with HCC (CHC-HCC). Twenty-seven healthy individuals also participated as controls. Flow cytometry was used to analyze CD19+ B cell subsets based on the expression of CD24 and CD38. CD19+CD24hiCD38hi Immature/transitional B cells elevated in diabetic than non-diabetic patients. In diabetic patients, while CD19+CD24+CD38− primarily memory B cells were higher in CHC-N and CHC-HCC groups than LC with a good predictive accuracy of LC, the opposite was observed for CD19+CD24−CD38− new memory B cells. Only in diabetic patients, the CD19+CD24intCD38int naïve mature B cells were high in CHC-HCC patients with good prognostic accuracy of HCC. Merely in diabetic patients, several correlations were observed between B cell subsets and liver function. Immature/transitional B cells increase remarkably in diabetic CHCpatients and might have a role in liver disease progression. Memory and Naïve B cells are good potential predictors of LC and HCCin diabetic CHCpatients, respectively. Further studies are needed to investigate the role of the CD19+CD24−CD38− new memory B cells in disease progression in CHC patients.

Reduced Circulating Memory B-Cells Account for Humoral Immune Defects in Multiple Myeloma, Associated with Infective Risk and Poor Vaccination Responses

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3393-3393
Author(s):  
Jonathan Carmichael ◽  
Clive R Carter ◽  
Christopher Parrish ◽  
Charlotte Kallmeyer ◽  
Sylvia Feyler ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Bacterial Infections ◽  
Memory B Cells ◽  
Antibody Responses ◽  
Progressive Reduction ◽  
Cell Numbers ◽  
Humoral Immune ◽  
Transitional B Cells ◽  
B Cell Subsets

Abstract Multiple myeloma (MM) is characterized by an increased risk of infection due to the immunosuppressive effect of the disease and conjointly of therapy. Furthermore, there is impaired responses to vaccination to counter the infection risk. The factors that underpin defective B-cell homeostasis and effective humoral immunity are not clear, nor are the extent of the defects. Also, the level of impaired humoral immunity in MGUS is not fully understood. The aim of this study was to delineate the circulating B-cell populations and recall antibody responses in patients with MGUS & MM, compared to age-matched controls, correlating with the responsiveness to vaccinations, incidence of infective complications and concomitant therapy. We performed comprehensive B-cell immunophenotyping by multi-parameter flow cytometry of peripheral blood samples from patients with MGUS (n=16), asymptomatic MM (n=18) and MM (n=108) with a median age of 63 years (range 38-94) comparing them to age-matched controls (n=9). B-cell subsets included naïve (CD19+CD27-), memory (CD19+CD27+; non-switch CD19+IgD+CD27+, switch CD19+IgD-CD27+), transitional (CD19+CD27-CD24hiCD38hi) & regulatory (CD19+CD27+CD24hi) B-cells. Serum uninvolved total IgG, IgM & IgA levels along with vaccine-specific antibody responses were analysed. There is a progressive decrease in the uninvolved immunoglobulin classes with significant reduction in total IgA (p=0.006) and IgM levels (p=0.007) in aMM/MM compared to MGUS & control (Figure 1). When anti-pneumococcal antibodies were measured, only 30% of aMM/MM patients had adequate protective levels compared to 79% of age-matched controls, with 40% of aMM/MM patients with inadequate levels experiencing recurrent respiratory tract infections compared to 25% of aMM/MM patients with adequate proactive antibodies. Patients with MGUS, aMM and MM have lower total B-cell numbers compared to controls (1-way ANOVA p=0.004; Figure 1). The reduction in B-cell numbers were primarily the consequence of reduced memory B-cells (percentage and absolute 1-way ANOVA p<0.0001), noted in both MGUS and aMM/MM but a progressive reduction with increasing disease activity (MGUS>aMM>MM). Furthermore, a correlation with total IgG levels & memory B-cell numbers is evident (r2=-0.053) & progressive reduction in memory B-cell numbers is seen with advancing cycles of therapy. The ratio of switch:non-switch memory B-cells is unaltered (control 1.05, MGUS 0.53, aMM 1.41 & MM 1.49; 1-way ANOVA p=ns). Conversely, there is a compensatory increase in the percentage of transitional B-cells when increasing disease stage is compared to controls (control 7.38% (95%ci 4.9,9.9) vs MGUS 14.0% (95%ci 7.4, 20.7) vs aMM 14.95% (95%ci 8, 21.9); 1-way ANOVA p<0.001) but a reduction is noted in MM (5.82%, 95%ci 4.5,7.2; p<0.0001), primarily being driven by sequential lines of therapy. As a consequence, the ratio of Memory:transitional B-cells is significantly reduced in aMM/MM compared to MGUS & controls (control 10.35, MGUS 20.46, aMM 7.74 & MM 4.57; 1-way ANOVA p=0.006), associated with increasing incidence of bacterial infections. A non-significant correlation is seen between transitional B-cells and total uninvolved immunoglobulin levels and with recall responses to vaccinations. There is a progressive decrease in the CD19+CD27+CD24hi B-cell subset between control and plasma cell dyscrasias (control 20.4% (95%ci 15.5,25.2), MGUS 14.0% (95%ci 7.4, 20.7), aMM 14.95% (95%ci 8, 21.9) & MM 5.82%, 95%ci 4.5,7.2; p<0.0001), primarily being driven by sequential lines of therapy and associated with increased incidence of infection. This study illustrates that patients with myeloma demonstrate reduced total circulating B-cells primarily as a consequence of reduced memory B-cells, associated with reduced immunoglobulin and recall antibody responses. This is associated with increased incidence of bacterial infections and is worsened by sequential exposure to lymphodepleting therapies. Of particular importance is the identified aberration in B-cell subsets seen in MGUS compared with age-matched control, indicative of humoral immune dysregulation highlighting that MGUS may not be an immunologically inert disorder. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

B Cell With Regulatory Function Are Enriched Within Transitional and IgM Memory B Cell Subsets In Healthy Donors But Are Reduced and Functionally Impaired In Patients With Chronic Graft-Versus-Host Disease

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4478-4478
Author(s):  
Anushruti Sarvaria ◽  
Ahmad Khoder ◽  
Abdullah Alsuliman ◽  
Claude Chew ◽  
Takuya Sekine ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Memory B Cells ◽  
Regulatory Function ◽  
Healthy Controls ◽  
Transitional B Cells ◽  
B Cell Subsets

The immunosuppressive function of IL10 producing regulatory B cells (Bregs) has been shown in several murine models of inflammation and autoimmune disease. However, there is a paucity of data regarding the existence of an equivalent regulatory B cell subset in healthy individuals and their potential role in the pathogenesis of chronic graft-versus-host disease (cGVHD) remains unknown. Here, we examined the functional regulatory properties of peripheral blood (PB)-derived human B cell subsets from healthy individuals. In addition, we carried out studies to explore their role in cGVHD, using B cells from patients following allogeneic stem cell transplantation (HSCT). We first determined whether human IL-10 producing B cells are enriched within any othe previously described human B cell subsets: CD19+IgM+CD27+ IgM memory, CD19+IgM-CD27+ switched memory, CD19+IgM+CD27- naive, and and transitional CD19+CD24hiCD38hi. Following in vitro stimulation with CD40 ligand, the majority of IL-10 producing B cells were found within the CD24hiCD38hi transitional and CD19+IgM+CD27+B cell subsets. We next assessed the regulatory properties of the PB-derived B cell subsets, by sort-purifying IgM memory (CD19+IgM+CD27+), switched memory (CD19+IgM-CD27+), naïve (CD19+IgM+CD27-) and transitional (CD19+CD24hiCD38hi) B cells from healthy controls, and cultured them 1:1 with autologous magnetic-bead purified CD4+ T cells. CD3/CD28 stimulated CD4+ T cells cultured with either CD19+IgM+CD27- naïve or CD19+IgM-CD27+ switched memory B cells proliferated to the same extent and produced equivalent amounts of IFN-γ to cultures containing CD4+ T cells alone. In contrast, culture of CD4+ T cells with IgM memory and transitional B cells significantly suppressed CD4+ T cell proliferation [median percent proliferating CD4+ T cells 52.5%; (33%-75%)] and 51% (25%-63%)], respectively when compared with CD3/CD28 stimulated CD4+ T cells (positive control) [89.5% (75%-92%], p=0.0001. The inhibitory effect of IgM memory and transitional B cells on CD4+ T cell proliferation was cell dose dependent with the highest suppression observed at a ratio of 1:1. These data suggest that human PB transitional and IgM memory B cells are endowed with regulatory function. We next examined if the in vitro suppressive effect of transitional and IgM memory B cells is mediated by regulatory T cells (Tregs). For this purpose, CD4+ T cells were depleted of CD127lo CD25hi CD4+ T cells by magnetic cell purification. B cell subsets were cultured with CD3/CD28 stimulated CD4+ CD25- T cells at a ratio of 1:1. IgM memory and transitional B cells were able to significantly suppress the proliferation and Th1 cytokine response by CD4+ CD25- T cells compared to cultures containing CD4+ CD25-T cells alone, indicating that the suppressive activity of Bregs is independent of Tregs. To further understand the underlying mechanims though which Bregs exert T-cell suppression, we used antibody blockade experiments and showed that this suppressive effect was mediated partially via the provision of IL-10, but not TGF-ß. Using transwell experiments, we further determined that the suppressive function of Bregs is also partly dependent on direct T cell/B cell contact. We next assessed whether the activity of Breg cells might be altered in patients with cGVHD. B cells from patients with cGVHD were refractory to CD40 stimulation and produced less IL-10 when compared to patients without cGVHD post-SCT and healthy controls, [1.02% (0.22-2.26) vs.1.72% (0.8-5.52) vs. 2.16 (1.3- 5.6), p=0.001]. Likewise, the absolute number of IL-10 producing B cells was significantly lower in cGvHD patients compared to patients without cGVHD and healthy controls (p=0.007), supporting both a qualitative and quantitative defect in IL-10 producing B cells in cGvHD. Our combined studies provide important new data defining the phenotype of B cell populations enriched in regulatory B cells in healthy humans and provide evidence for a defect in the activity of such cells in patients with cGVHD post-SCT. In association with previous reports showing defects in Treg cell activity in GVHD, our results suggest the existence of a broad range of deficiencies in immune regulatory cell function in cGvHD patients. * Both Anushruti Sarvaria and Ahmad K contributed equally. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Dual-reactive B cells are autoreactive and highly enriched in the plasmablast and memory B cell subsets of autoimmune mice

2012 ◽  
Vol 209 (10) ◽  
pp. 1797-1812 ◽  
Author(s):  
Emilie M. Fournier ◽  
Maria-Gabriela Velez ◽  
Katelyn Leahy ◽  
Cristina L. Swanson ◽  
Anatoly V. Rubtsov ◽  
...  
Keyword(s):  
B Cells ◽  
Immune Responses ◽  
B Cell ◽  
Disease Progression ◽  
Memory B Cells ◽  
Cell Populations ◽  
Wild Type ◽  
Memory B Cell ◽  
Heavy Chains ◽  
B Cell Subsets

Rare dual-reactive B cells expressing two types of Ig light or heavy chains have been shown to participate in immune responses and differentiate into IgG+ cells in healthy mice. These cells are generated more often in autoreactive mice, leading us to hypothesize they might be relevant in autoimmunity. Using mice bearing Igk allotypic markers and a wild-type Ig repertoire, we demonstrate that the generation of dual-κ B cells increases with age and disease progression in autoimmune-prone MRL and MRL/lpr mice. These dual-reactive cells express markers of activation and are more frequently autoreactive than single-reactive B cells. Moreover, dual-κ B cells represent up to half of plasmablasts and memory B cells in autoimmune mice, whereas they remain infrequent in healthy mice. Differentiation of dual-κ B cells into plasmablasts is driven by MRL genes, whereas the maintenance of IgG+ cells is partly dependent on Fas inactivation. Furthermore, dual-κ B cells that differentiate into plasmablasts retain the capacity to secrete autoantibodies. Overall, our study indicates that dual-reactive B cells significantly contribute to the plasmablast and memory B cell populations of autoimmune-prone mice suggesting a role in autoimmunity.

scholarly journals Circulating B Cell Subsets from Untreated Diffuse Large B Cell Lymphoma (DLBCL) Patients Resemble Those of Patients with Autoimmune Disease

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4221-4221
Author(s):  
Jean L. Koff ◽  
Kevin S. Cashman ◽  
Vivien Warren ◽  
Kira Smith ◽  
Christopher R Flowers ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Research Funding ◽  
B Cell Lymphoma ◽  
Memory B Cells ◽  
Transitional B Cells ◽  
Large B Cell Lymphoma ◽  
Pre Treatment ◽  
B Cell Subsets ◽  
Cell Profile

Abstract Introduction Diffuse large B cell lymphoma (DLBCL) is a clinically and genetically heterogeneous malignancy that can arise from B cell-mediated autoimmune (AI) diseases such as systemic lupus erythematosus (SLE). Profiling B cell subsets by multicolor flow cytometry can delineate SLE pts from healthy controls and correlates with differences in SLE outcomes (Tipton CM, Nat Immunol 2015). Emerging data suggest that expansions of IgD-CD27- ("double-negative," DN) memory B cells in SLE are comprised of a novel subset representing pre-plasma cell effector B cells (Sanz MS under review), with at least 15% of DN B cells expressing autoantibodies. Given the etiologic link between autoimmunity and DLBCL, we hypothesized that B cell profiling in DLBCL patients (pts) with and without concomitant AI disease could identify variations in B cell repertoire similar to those observed in SLE patients and reveal links to distinct subtype variations based on biology and etiology. Methods Pts with DLBCL were prospectively identified and consented to participate. All pts were followed longitudinally for clinical data annotation and sample re-collection. Peripheral blood mononuclear cells were isolated from whole blood using density-gradient centrifugation, stained with a 13-color cocktail that included fluorochrome-conjugated mouse monoclonal antibodies to CD3, CD11c, CD19, CD20, CD21, CD24, CD27, CD38, IgD, and Ig light chain kappa and lambda, and then analyzed via flow cytometry with gating analysis using FlowJo. After excluding dead cells, doublets, and non-lymphocytes, we gated on CD19+ B cells and assessed subpopulations based first on expression of IgD and CD27 to distinguish mature-naïve B cells (IgD+CD27-) from switched (IgD-CD27+), unswitched (IgD+CD27+), and DN (IgD-CD27-) memory B cells. Additional cell surface markers (e.g., CD24, CD38) defined other subsets such as antibody-secreting cells and transitional B cells. We examined pre-treatment B cell profile to characterize baseline variations in DLBCL. To examine changes in B cell profile relative to treatment, DLBCL pt samples were evaluated: after completion of standard first-line chemoimmunotherapy; in remission ≥ 1 year from treatment; and at relapse. The Kruskal-Wallis test was used to compare B cell subset distributions between samples. Results Peripheral blood was collected from a total of 59 DLBCL pts, with 8 pts contributing samples at >1 time-point. B cell profiling of pre-treatment samples (n=12) revealed two distinct phenotypes according to CD27 and IgD expression: 7 pts' profiles resembled those of healthy controls (42%), and 5 exhibited diminished unswitched memory B cells (<10% of CD19+ cells), similar to SLE pts (Figures 1 and 2). Within the latter group, 4 pts also exhibited DN expansion (>10% of CD19+ cells), a phenotype similar to SLE pts with poor outcomes. Plasmablasts, transitional B cells, switched memory and naïve B cells in untreated DLBCL were not significantly expanded. As expected, CD19+ B cells were uniformly depleted following chemoimmunotherapy, constituting <1% lymphocytes until about 9 months post-treatment. Prior to B cell reconstitution, this small B cell population consisted predominantly of DN cells (Figure 3). Conclusions Intriguingly, a subset of untreated DLBCL pts exhibit diminished unswitched memory B cells and DN expansion characteristic of SLE pts. It is unclear whether the DN expansion we detected in non-AI-associated DLBCL represents an immune response to tumor or a state of subclinical immune dysregulation that predisposes to DLBCL development, perhaps via chronic antigen stimulation as postulated in AI-associated lymphomas. Longitudinal studies are ongoing to evaluate associations between abnormal B cell profiles, clinical factors, and survival outcomes Disclosures Flowers: BeiGene: Research Funding; TG Therapeutics: Research Funding; Gilead: Research Funding; Abbvie: Research Funding; Pharmacyclics/ Janssen: Consultancy; Bayer: Consultancy; Acerta: Research Funding; Karyopharm: Consultancy; Genentech/Roche: Consultancy; National Cancer Institute: Research Funding; Celgene: Research Funding; Millennium/Takeda: Research Funding; Spectrum: Consultancy; Genentech/Roche: Research Funding; Janssen Pharmaceutical: Research Funding; V Foundation: Research Funding; OptumRx: Consultancy; Burroughs Wellcome Fund: Research Funding; Pharmacyclics: Research Funding; Abbvie: Consultancy, Research Funding; Eastern Cooperative Oncology Group: Research Funding; Gilead: Consultancy; Denovo Biopharma: Consultancy.

scholarly journals AB0025 B-CELL SUBSETS AS ADDITIONAL DIAGNOSTIC TOOL FOR PRIMARY SJOGREN’S SYNDROME AND SYSTEMIC LUPUS ERYTHEMATOSUS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1315.1-1316
Author(s):  
S. Benevolenskaya ◽  
I. Kudryavtsev ◽  
M. Serebriakova ◽  
I. Grigor’eva ◽  
A. Budkova ◽  
...  
Keyword(s):  
B Cells ◽  
Discriminant Analysis ◽  
B Cell ◽  
Sjögren’S Syndrome ◽  
Sjögren's Syndrome ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Transitional B Cells ◽  
B Cell Subsets ◽  
Sjögren‘S Syndrome

Background:Systemic lupus erythematosus (SLE) and primary Sjögren’s syndrome (pSS) are chronic complex disorders with an autoimmune background, multifactorial etiology, multiple circulating antinuclear antibodies and damage of various organs. SLE and pSS have several similar clinical and serological aspects; likewise, SLE and Sjögren’s syndrome may coexist (so-called secondary Sjögren’s syndrome). However, applied classification criteria do not differentiate SLE and pSS. It is known that humoral immunity plays significant part in pathogenesis of those diseases; hereby, we can expect imbalances in B cell subset frequencies during SLE and pSS.Objectives:To investigate clinical utility of B cell subsets in distinguish SLE and pSS during diagnosis.Methods:A total of 25 SLE patients, 25 SS patients and 49 healthy volunteers (HV) were included in the study. The diagnosis of SLE was performed according to the 2019 EULAR – ACR classification criteria, the diagnosis of pSS - according to the 2016 EULAR – ACR criteria. Phenotyping of blood B cell subsets was done using flow cytometry. Total peripheral blood B cells were identified using CD19 expression, distinct B cell subsets were characterized by IgD, CD38 and CD27 expression. All of the statistical analysis of data was performed with STATISTICA Version 12.0 Inc. (USA).Results:We evaluated the percentages of circulating B-cell subsets using three major classification schemes based on the relative co-expression of either IgD/CD38 (so-called “Bm1-Bm5” classification), IgD/CD27 and CD38/CD27. A discriminant analysis was performed for all B cell classifications. Analysis of CD38 and CD27 co-expression demonstrated most significant separation between patients with SLE and pSS (fig. 1). Moreover, discriminant analysis carried out by using a forward stepwise model demonstrated that the top significance was documented while assessing the percentage of plasmoblasts (CD27hiCD38hi), resting memory B-cells (CD27dimCD38low), mature active B-cells (CD27dimCD38dim), naive mature B-cells (CD27dimCD38low), as well as counting the absolute numbers of transitional B-cells (CD27lowCD38hi), model percent correct was 78,6% (p <0,05, tab.1).Figure 1.Graphic distribution of SLE and pSS patients as well as HV analyzed by discriminant analysis.Conclusion:B cell subsets might provide a useful diagnostic tool for distinction SLE and pSS. More research needed to investigate clinical value of B-cell subsets in autoimmune rheumatic diseases.Table 1.Peripheral B-cell subset composition in SLE and SS patients vs. HV group assessed by discriminant analysis.ParameterF-testp-levelPlasmoblasts (CD27hiCD38hi), %7,93<0.001Resting memory B-cells (CD27dimCD38low), %13,72<0.001Transitional B-cells (CD27lowCD38hi)29,74<0.001Mature active B-cells (CD27dimCD38dim), %5,20<0.001Naive mature B-cells (CD27dimCD38low), %3,100.049Double negative (CD27lowCD38low), %1,980,14Resting memory B-cells (CD27dimCD38low)1,020,36Double negative (CD27lowCD38low)2,320,10Plasmoblasts (CD27hiCD38hi)1,020,36Naive mature B-cells (CD27dimCD38low)1,030,36Mature active B-cells (CD27dimCD38dim)1,020,36Transitional B-cells (CD27lowCD38hi), %1,030,36Disclosure of Interests:None declared

Impact of genotype 3 on clinical outcome in patients with hepatitis C: both diabetes meliitus and liver disease progression

2017 ◽  
Vol 66 (1) ◽  
pp. S711-S712
Author(s):  
W. Zanjir ◽  
R. Maan ◽  
B. Hansen ◽  
O. Cerocchi ◽  
H. Janssen ◽  
...  
Keyword(s):  
Liver Disease ◽  
Hepatitis C ◽  
Clinical Outcome ◽  
Disease Progression ◽  
Genotype 3 ◽  
Liver Disease Progression

scholarly journals Marginating transitional B cells modulate neutrophils in the lung during inflammation and pneumonia

2021 ◽  
Vol 218 (9) ◽  
Author(s):  
John Podstawka ◽  
Sarthak Sinha ◽  
Carlos H. Hiroki ◽  
Nicole Sarden ◽  
Elise Granton ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Regulatory Networks ◽  
Vascular Inflammation ◽  
Transitional B Cells ◽  
Pulmonary Capillaries ◽  
Life Threatening ◽  
B Cell Subsets

Pulmonary innate immunity is required for host defense; however, excessive neutrophil inflammation can cause life-threatening acute lung injury. B lymphocytes can be regulatory, yet little is known about peripheral transitional IgM+ B cells in terms of regulatory properties. Using single-cell RNA sequencing, we discovered eight IgM+ B cell subsets with unique gene regulatory networks in the lung circulation dominated by transitional type 1 B and type 2 B (T2B) cells. Lung intravital confocal microscopy revealed that T2B cells marginate in the pulmonary capillaries via CD49e and require CXCL13 and CXCR5. During lung inflammation, marginated T2B cells dampened excessive neutrophil vascular inflammation via the specialized proresolving molecule lipoxin A4 (LXA4). Exogenous CXCL13 dampened excessive neutrophilic inflammation by increasing marginated B cells, and LXA4 recapitulated neutrophil regulation in B cell–deficient mice during inflammation and fungal pneumonia. Thus, the lung microvasculature is enriched in multiple IgM+ B cell subsets with marginating capillary T2B cells that dampen neutrophil responses.

scholarly journals Complexity of the human memory B-cell compartment is determined by the versatility of clonal diversification in germinal centers

2015 ◽  
Vol 112 (38) ◽  
pp. E5281-E5289 ◽  
Author(s):  
Bettina Budeus ◽  
Stefanie Schweigle de Reynoso ◽  
Martina Przekopowitz ◽  
Daniel Hoffmann ◽  
Marc Seifert ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Clone ◽  
Human Memory ◽  
Memory B Cells ◽  
Sequencing Analysis ◽  
Cell Compartment ◽  
Memory B Cell ◽  
Cell Clones ◽  
B Cell Subsets

Our knowledge about the clonal composition and intraclonal diversity of the human memory B-cell compartment and the relationship between memory B-cell subsets is still limited, although these are central issues for our understanding of adaptive immunity. We performed a deep sequencing analysis of rearranged immunoglobulin (Ig) heavy chain genes from biological replicates, covering more than 100,000 memory B lymphocytes from two healthy adults. We reveal a highly similar B-cell receptor repertoire among the four main human IgM+ and IgG+ memory B-cell subsets. Strikingly, in both donors, 45% of sequences could be assigned to expanded clones, demonstrating that the human memory B-cell compartment is characterized by many, often very large, B-cell clones. Twenty percent of the clones consisted of class switched and IgM+(IgD+) members, a feature that correlated significantly with clone size. Hence, we provide strong evidence that the vast majority of Ig mutated B cells—including IgM+IgD+CD27+ B cells—are post-germinal center (GC) memory B cells. Clone members showed high intraclonal sequence diversity and high intraclonal versatility in Ig class and IgG subclass composition, with particular patterns of memory B-cell clone generation in GC reactions. In conclusion, GC produce amazingly large, complex, and diverse memory B-cell clones, equipping the human immune system with a versatile and highly diverse compartment of IgM+(IgD+) and class-switched memory B cells.

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