Background: Regulatory B cells(Bregs) is an indispensable element in inducing immune tolerance after liver transplantation. As one of the microRNAs(miRNAs), mi R-29a-3p also inhibits translation by degrading the targe...Background: Regulatory B cells(Bregs) is an indispensable element in inducing immune tolerance after liver transplantation. As one of the microRNAs(miRNAs), mi R-29a-3p also inhibits translation by degrading the target mRNA, and yet the relationship between Bregs and mi R-29a-3p has not yet been fully explored. This study aimed to investigate the impact of miR-29a-3p on the regulation of differentiation and immunosuppressive functions of memory Bregs(m Bregs) and ultimately provide potentially effective therapies in inducing immune tolerance after liver transplantation. Methods: Flow cytometry was employed to determine the levels of Bregs in peripheral blood mononuclear cells. TaqMan low-density array miRNA assays were used to identify the expression of different miRNAs, electroporation transfection was used to induce mi R-29a-3p overexpression and knockdown, and dual luciferase reporter assay was used to verify the target gene of miR-29a-3p. Results: In patients experiencing acute rejection after liver transplantation, the proportions and immunosuppressive function of m Bregs in the circulating blood were significantly impaired. mi R-29a-3p was found to be a regulator of m Bregs differentiation. Inhibition of miR-29a-3p, which targeted nuclear factor of activated T cells 5(NFAT5), resulted in a conspicuous boost in the differentiation and immunosuppressive function of m Bregs. The inhibition of mi R-29a-3p in CD19~+ B cells was capable of raising the expression levels of NFAT5, thereby promoting B cells to differentiate into m Bregs. In addition, the observed enhancement of differentiation and immunosuppressive function of m Bregs upon mi R-29a-3p inhibition was abolished by the knockdown of NFAT5 in B cells. Conclusions: mi R-29a-3p was found to be a crucial regulator for m Bregs differentiation and immunosuppressive function. Silencing mi R-29a-3p could be a potentially effective therapeutic strategy for inducing immune tolerance after liver transplantation.展开更多
BACKGROUND The complexity of the immune microenvironment has an impact on the treatment of colorectal cancer(CRC),one of the most prevalent malignancies worldwide.In this study,multi-omics and single-cell sequencing t...BACKGROUND The complexity of the immune microenvironment has an impact on the treatment of colorectal cancer(CRC),one of the most prevalent malignancies worldwide.In this study,multi-omics and single-cell sequencing techniques were used to investigate the mechanism of action of circulating and infiltrating B cells in CRC.By revealing the heterogeneity and functional differences of B cells in cancer immunity,we aim to deepen our understanding of immune regulation and provide a scientific basis for the development of more effective cancer treatment strategies.AIM To explore the role of circulating and infiltrating B cell subsets in the immune microenvironment of CRC,explore the potential driving mechanism of B cell development,analyze the interaction between B cells and other immune cells in the immune microenvironment and the functions of communication molecules,and search for possible regulatory pathways to promote the anti-tumor effects of B cells.METHODS A total of 69 paracancer(normal),tumor and peripheral blood samples were collected from 23 patients with CRC from The Cancer Genome Atlas database(https://portal.gdc.cancer.gov/).After the immune cells were sorted by multicolor flow cytometry,the single cell transcriptome and B cell receptor group library were sequenced using the 10X Genomics platform,and the data were analyzed using bioinformatics tools such as Seurat.The differences in the number and function of B cell infiltration between tumor and normal tissue,the interaction between B cell subsets and T cells and myeloid cell subsets,and the transcription factor regulatory network of B cell subsets were explored and analyzed.RESULTS Compared with normal tissue,the infiltrating number of CD20+B cell subsets in tumor tissue increased significantly.Among them,germinal center B cells(GCB)played the most prominent role,with positive clone expansion and heavy chain mutation level increasing,and the trend of differentiation into memory B cells increased.However,the number of plasma cells in the tumor microenvironment decreased significantly,and the plasma cells secreting IgA antibodies decreased most obviously.In addition,compared with the immune microenvironment of normal tissues,GCB cells in tumor tissues became more closely connected with other immune cells such as T cells,and communication molecules that positively regulate immune function were significantly enriched.CONCLUSION The role of GCB in CRC tumor microenvironment is greatly enhanced,and its affinity to tumor antigen is enhanced by its significantly increased heavy chain mutation level.Meanwhile,GCB has enhanced its association with immune cells in the microenvironment,which plays a positive anti-tumor effect.展开更多
Accumulating evidence has demonstrated the involvement of B cells in neuroinflammation and neuroregeneration.However,the role of B cells in ischemic stroke remains unclear.In this study,we identified a novel phenotype...Accumulating evidence has demonstrated the involvement of B cells in neuroinflammation and neuroregeneration.However,the role of B cells in ischemic stroke remains unclear.In this study,we identified a novel phenotype of macrophage-like B cells in brain-infiltrating immune cells expressing a high level of CD45.Macrophage-like B cells chara cterized by co-expression of B-cell and macrophage markers,showed stronger phagocytic and chemotactic functions compared with other B cells and showed upregulated expression of phagocytosis-related genes.Gene Ontology analysis found that the expression of genes associated with phagocytosis,including phagosome-and lysosome-related genes,was upregulated in macrophage-like B cells.The phagocytic activity of macrophage-like B cells was ve rified by immunostaining and three-dimensional reconstruction,in which TREM2-labeled macrophage-like B cells enwrapped and internalized myelin debris after cerebral ischemia.Cell-cell interaction analysis revealed that macrophage-like B cells released multiple chemokines to recruit peripheral immune cells mainly via CCL pathways.Single-cell RNA sequencing showed that the transdiffe rentiation to macrophage-like B cells may be induced by specific upregulation of the transcription factor CEBP fa mily to the myeloid lineage and/or by downregulation of the transcription factor Pax5 to the lymphoid lineage.Furthermore,this distinct B cell phenotype was detected in brain tissues from mice or patients with traumatic brain injury,Alzheimer’s disease,and glioblastoma.Overall,these results provide a new perspective on the phagocytic capability and chemotactic function of B cells in the ischemic brain.These cells may serve as an immunotherapeutic target for regulating the immune response of ischemic stroke.展开更多
Objective:Several studies indicated that tonsillectomy can improve the prognosis of patients with immunoglobulin A nephropathy(IgAN).However,the relationship between tonsillar immunity and IgAN is still unclear.Method...Objective:Several studies indicated that tonsillectomy can improve the prognosis of patients with immunoglobulin A nephropathy(IgAN).However,the relationship between tonsillar immunity and IgAN is still unclear.Methods:A total of 14 IgAN patients were recruited in the current study from May 2015 to April 2016 in Tongji Hospital.B cells,dendritic cells(DCs),and IgAl positive cells in human tonsils were detected using immunofluorescence and immunohistochemistry.Correlations between these cells and clinicopathologic features were evaluated.展开更多
BACKGROUND： Chronic hepatitis C virus （HCV） infection causes the skewing and activation of B cell subsets, but the characteristics of IgG＋ B cells in patients with chronic hepa- titis C （CHC） infection have not ...BACKGROUND： Chronic hepatitis C virus （HCV） infection causes the skewing and activation of B cell subsets, but the characteristics of IgG＋ B cells in patients with chronic hepa- titis C （CHC） infection have not been thoroughly elucidated. CD4＋CXCR5＋ follicular helper T （Tfh） cells, via interleukin （IL）-21 secretion, activate B cells. However, the role of CD4＋CXCR5＋ T cells in the activation ofIgG＋ B cells in CHC patients is not clear. METHODS： The frequency of IgG＋ B cells, including CD27-IgG＋ B and CD27＋IgG＋ B cells, the expression of the activation markers （CD86 and CD95） in IgG＋ B cells, and the percentage of circu- lating CD4＋CXCR5＋ T cells were detected by flow cytometry in CHC patients （n=70） and healthy controls （n=25）. The con- centrations of serum IL-21 were analyzed using ELISA. The role of CD4＋CXCR5＋ T cells in the activation of IgG＋ B cells was investigated using a co-culture system. RESULTS： A significantly lower proportion of CD27＋IgG＋ B cells with increased expression of CD86 and CD95 was observed in CHC patients. The expression of CD95 was negatively correlated with the percentage of CD27＋IgG＋ B cells, and it contributed to CD27＋IgG＋ B cell apoptosis. Circulating CD4＋CXCR5＋ T cells and serum IL-21 were significantly increased in CHC patients. Moreover, circulating CD4＋CXCR5＋ T cells from CHC patients induced higher expressions of CD86 and CD95 in CD27＋IgG＋ B cells in a co-culture system; the blockade of the IL-21 decreased the expression levels of CD86 and CD95 in CD27＋IgG＋ B cells.CONCLUSIONS： HCV infection increased the frequency of CD4＋CXCR5＋ T cells and decreased the frequency of CD27＋IgG＋ B cells. CD4＋CXCR5＋ T cells activated CD27＋IgG＋ B cells via the secretion of IL-21.展开更多
Objective： To observe the effect of the artesunate （ART） on cellular proliferation in vitro, to search for the possible anti-tumor mechanism of ART on endometrial carcinoma at the molecular level and to provide the...Objective： To observe the effect of the artesunate （ART） on cellular proliferation in vitro, to search for the possible anti-tumor mechanism of ART on endometrial carcinoma at the molecular level and to provide the experimental and theoretical foundations for the clinical applications of ART. Methods： The cell proliferation was observed by microscope; MTT was used to examine the effects of ART on proliferation of HEC-1B cells, and flow cytometric analysis was used to detect cell cycle and apoptosis. The human endometrial carcinoma HEC-1B cells were conventionally cultured; ART was administered with a concentration of 40 μg/ml before the total RNA were extracted, mRNA expression of Survivin, Caspase-3, N-Cadherin, E-Cadherin, Fibronectinl and Cox-2 were detected using RT-PCR. Results： ART reduced proliferation in human endometrial carcinoma cell line HEC-1B in a dose- and time-dependent effect. The cells of G0/G1 stage were significantly increased （P〈0.05）, but the cells of G2/M stages were significantly decreased （P〈0.05）, so it has shown that the cell cycle was probably blocked in G0/G1 stage. After intervention with ART at 20 and 80 μg/ml for 48 h, cellular apoptosis rate respectively was （36.42±0.77）% and （11.77±0.58）%, and the difference was statistically significant compared with the control （[6.64±0.191%, P〈0.01）. The expression of Cox-2 mRNA in the ART group was lower than those of control group, yet the expression of Caspase-3 and E-Cadherin mRNA in the ART group was higher than those of control group. Conclusion： ART can inhibit HEC-1B cell growth and proliferation in a dose- and time-dependent manner. Furthermore, ART can induce apoptosis in a dose-dependent manner. ART is able to downregulate Cox-2 mRNA expression and to upregulate E-Cadherin and Caspase-3 mRNA expression. So we can conclude that ART could induce the endometrial carcinoma HEC-1B cell apoptosis and inhibit tumor cell proliferation.展开更多
AIM： To investigate the association between IL-10-producing regulatory B（B10） cells and the clinical features of thyroid-associated orbitopathy（TAO）. METHODS： A total of 30 patients with TAO were recruited at Zh...AIM： To investigate the association between IL-10-producing regulatory B（B10） cells and the clinical features of thyroid-associated orbitopathy（TAO）. METHODS： A total of 30 patients with TAO were recruited at Zhongshan Ophthalmic Center from May 2015 to December 2015. Peripheral blood mononuclear cells（PBMCs） were separated from blood samples of 30 TAO patients and 16 healthy controls and stimulated with CD40 ligand and CpG for 48h. The frequency of IL-10＋ B cells was examined by flow cytometry and the correlation between the frequency of IL-10＋ B cells and clinical features of TAO was analyzed by SPSS. RESULTS： The frequency of IL-10＋ B cells among CD19＋ B cells in TAO patients was significantly lower than in healthy controls（TAO： 4.66%±1.88% vs healthy control： 6.82%±2.40%, P〈0.01）. The frequency of IL-10＋ B cells showed a positive correlation with disease activity of TAO measured by Clinical Activity Score（CAS）（r=0.50, P〈0.01）, and became higher in TAO patients with family history of Graves＇ disease（GD）（P=0.04）. CONCLUSION： The decrease of the frequency of IL-10＋ B cells in TAO patients indicates the deficiency of B10 cells in TAO, and the positive association with disease activity suggests its important role in TAO inflammation regulation.展开更多
BACKGROUND Recent evidence has indicated the role of B cells and B cell-activating factor(BAFF)in the development of hepatocellular carcinoma(HCC).AIM To characterize circulating BAFF receptor expression and B cell su...BACKGROUND Recent evidence has indicated the role of B cells and B cell-activating factor(BAFF)in the development of hepatocellular carcinoma(HCC).AIM To characterize circulating BAFF receptor expression and B cell subpopulations in patients with hepatitis B virus(HBV)-related HCC.METHODS Peripheral blood samples collected from 41 patients with chronic HBV infection(25 patients without HCC and 16 patients with HCC)and 9 healthy controls were assessed for BAFF receptors[BAFF-R(B cell-activating factor receptor),transmembrane activator and cyclophilin ligand interactor,B-cell maturation antigen]and B cell subpopulations by multicolor flow cytometry.RESULTS The frequency of BAFF-R expressing B cells to total B cells was significantly lower in patients with HCC(3.39%±2.12%)compared with the non-HCC group(5.37%±1.90%)and healthy controls(6.23%±2.32%),whereas there was no difference in transmembrane activator and cyclophilin ligand interactor and Bcell maturation antigen.The frequencies of CD27+Ig D+memory B cells,CD27+Ig Dclass-switched memory B cells and plasmablasts were significantly lower in the patients with HCC compared to patients without HCC(1.23±1.17 vs 3.09±1.55,P=0.001,0.60±0.44 vs 1.69±0.86,P<0.0001 and 0.16±0.12 vs 0.37±0.30,P=0.014,respectively).However,the ratio of na?ve and transitional B cell did not differ significantly between the three groups.In addition,decreased BAFF-R expression on B cells was significantly correlated with large tumor size and advanced tumor stage.CONCLUSION Our data demonstrated BAFF-R expression was reduced in B cells that involved with the frequencies of B cells maturation in patients with HCC.The depletion of BAFF-R might play an important role in the development of HCC in patients with chronic HBV infection.展开更多
Pancreatic cancer is a disease with high unmet clinical need.Pancreatic cancer is also characterised by an intense fibrotic stroma,which harbours many immune cells.Studies in both human and animal models have demonstr...Pancreatic cancer is a disease with high unmet clinical need.Pancreatic cancer is also characterised by an intense fibrotic stroma,which harbours many immune cells.Studies in both human and animal models have demonstrated that the immune system plays a crucial role in modulating tumour onset and progression.In human pancreatic ductal adenocarcinoma,high B-cell infiltration correlates with better patient survival.Hence,B cells have received recent interest in pancreatic cancer as potential therapeutic targets.However,the data on the role of B cells in murine models is unclear as it is dependent on the pancreatic cancer model used to study.Nevertheless,it appears that B cells do organise along with other immune cells such as a network of follicular dendritic cells(DCs),surrounded by T cells and DCs to form tertiary lymphoid structures(TLS).TLS are increasingly recognised as sites for antigen presentation,T-cell activation,Bcell maturation and differentiation in plasma cells.In this review we dissect the role of B cells and provide directions for future studies to harness the role of B cells in treatment of human pancreatic cancer.展开更多
EBI2 is known as a kind of 7TM G protein-coupled receptors, and EBi2 gene is one of the most upregulated genes in Epstein-Barr virus （EBV） -infected lymphocytes. As a constitutively active receptor, EBI2 signals via...EBI2 is known as a kind of 7TM G protein-coupled receptors, and EBi2 gene is one of the most upregulated genes in Epstein-Barr virus （EBV） -infected lymphocytes. As a constitutively active receptor, EBI2 signals via Gai, and TM-II plays an important role in the signal transduct/on process. EBI2 is expressed mainly in mature, B cells and the expression level increases at the early stage of activation; subsequently, B cells are transferred into GC and the expression level is down-regulated. EBI2 can regulate independently and mediate synergistically the migration of B cell towards the extrafollicular areas and GC depending on chemo- kine receptors CXCR5 and CCR7 （EBII）. Differential expression of EBI2 receptor is conducive to accurate migration of B cells at different stages, thereby leading to appropriate irranunologic responses to T-dependent antigens. Recently, two research groups identified a specific oxysteml as the natural ligand for EBL2. Among all the oxysterols, 7α, 25-Dihydrexycholesteml （7a, 25-OHC） is the most effective ligand and activator, and EBI2-Oxysterol signal pathway plays an important role in adaptive immune responses. In addition, EBI2 is also closely related with specific kinds of autoimmune diseases, so it is considered as a negative regulator of the innate immune response in macrophages.展开更多
Immunoglobulin (Ig) M production can be induced by the interaction of thymus-independent type-2 (TI-2) antigen (Ag) with B cell Ag receptors (BCRs) without the involvement of conventional T cells;for IgG production th...Immunoglobulin (Ig) M production can be induced by the interaction of thymus-independent type-2 (TI-2) antigen (Ag) with B cell Ag receptors (BCRs) without the involvement of conventional T cells;for IgG production through the same process, however, a second signal is required. Previous studies have reported that invariant natural killer T (iNKT) cells may be responsible for the second signal involved in IgG production. In the present study, we addressed whether human iNKT cells could participate in the production of Ig against TI-2 Ag in vitro. Two major distinct subsets of human iNKT cells, CD4<sup>+</sup> CD8β<sup>-</sup> (CD4) and CD4<sup>-</sup> CD8β<sup>-</sup> [double negative (DN)] cells, were generated from peripheral blood monocytes from a healthy volunteer. BCR engagement, triggered by anti-IgM antibody stimulation, examined here as a model of BCR engagement triggered by TI-2 Ag, induced abundant IgM production by B cells. Both CD4 and DN iNKT cells reduced IgM production and conversely enhanced IgG production in a dose-dependent manner. In addition, IgG production by CD19<sup>+</sup>CD27<sup>-</sup> (naïve) and CD19<sup>+</sup>CD27<sup>+</sup> (memory) B cells was predominantly promoted by DNiNKT cells rather than CD4 iNKT cells;nevertheless, IgM production by both B cell subsets was similarly reduced by either subset of iNKT cells. These results suggest that the DN iNKT subsets may preferentially promote Ig class switching by B cells upon stimulation with TI-2 Ag.展开更多
B cells play immunomodulatory roles mainly by presenting antigens and producing antibodies. In recent years, some B cells were shown to exhibit regulatory functions. This type of B cell was named regulatory B cells(Br...B cells play immunomodulatory roles mainly by presenting antigens and producing antibodies. In recent years, some B cells were shown to exhibit regulatory functions. This type of B cell was named regulatory B cells(Bregs). Bregs can mediate immune tolerance to inhibit excessive inflammatory responses and to accelerate recovery of infl ammation by producing interleukin 10 and/or transforming growth factor β1 and other inhibitory cytokines. Studies showed that Bregs play important roles in parasites, bacteria, and viral infections. This study reviews biological characteristics, functions, and microsignal regulation of Bregs and their mechanism in infectious diseases and related research progress.展开更多
Objoctive： There is heterogeneity in the prognosis of gastric cancers staged according to the tumornodes-metastasis （TNM） system. This study evaluated the prognostic potential of an immune score system to supplemen...Objoctive： There is heterogeneity in the prognosis of gastric cancers staged according to the tumornodes-metastasis （TNM） system. This study evaluated the prognostic potential of an immune score system to supplement the TNM staging system. Mothodsg An immunohistochemical analysis was conducted to assess the density of T cells, B cells, and myeloid-derived suppressor cells （MDSCs） in cancer tissues from 100 stage IIIA gastric cancer patients; the expression of the high-mobility group protein B1 （HMGB1） was also evaluated in cancer cells. The relationship between the overall survival （OS）, disease-free survival （DFS）, and immunological parameters was analyzed.Results： An immune score system was compiled based on the prognostic role of the density ofT cells, B cells, MDSCs, and the expression of HMGB1 in cancer tissues. The median 5-year survival of this group of patient was 32%. However, the 5-year survival rates of 80.0%, 51.7%, 0%, 5.8%, and 0% varied among the patients with an immune score of 4 to those with an immune score of 0 based on the immune score system, respectively. Similarly, differences in DFS rates were observed among the immune score subgroups. Concluslons： An immune score system could effectively identify the prognostic heterogeneity within stage IliA gastric cancer patients, implying that this immune score system may potentially supplement the TNM staging system, and help in identifying a more homogeneous group of patients who on the basis of prognosis can undergo adjuvant therapy.展开更多
BACKGROUND Immune dysfunction is the crucial cause in the pathogenesis of inflammatory bowel disease(IBD),which is mainly related to lymphocytes(T or B cells,including memory B cells),mast cells,activated neutrophils,...BACKGROUND Immune dysfunction is the crucial cause in the pathogenesis of inflammatory bowel disease(IBD),which is mainly related to lymphocytes(T or B cells,including memory B cells),mast cells,activated neutrophils,and macrophages.As the precursor of B cells,the activation of memory B cells can trigger and differentiate B cells to produce a giant variety of inducible B cells and tolerant B cells,whose dysfunction can easily lead to autoimmune diseases,including IBD.AIM To investigate whether or not curcumin(Cur)can alleviate experimental colitis by regulating memory B cells and Bcl-6-Syk-BLNK signaling.METHODS Colitis was induced in mice with a dextran sulphate sodium(DSS)solution in drinking water.Colitis mice were given Cur(100 mg/kg/d)orally for 14 consecutive days.The colonic weight,colonic length,intestinal weight index,occult blood scores,and histological scores of mice were examined to evaluate the curative effect.The levels of memory B cells in peripheral blood of mice were measured by flow cytometry,and IL-1β,IL-6,IL-10,IL-7A,and TNF-αexpression in colonic tissue homogenates were analyzed by enzyme-linked immunosorbent assay.Western blot was used to measure the expression of Bcl-6,BLNK,Syk,and other signaling pathway related proteins.RESULTS After Cur treatment for 14 d,the body weight,colonic weight,colonic length,colonic weight index,and colonic pathological injury of mice with colitis were ameliorated.The secretion of IL-1β,IL-6,TNF-α,and IL-7A was statistically decreased,while the IL-35 and IL-10 levels were considerably increased.Activation of memory B cell subsets in colitis mice was confirmed by a remarkable reduction in the expression of IgM,IgG,IgA,FCRL5,CD103,FasL,PD-1,CD38,and CXCR3 on the surface of CD19^(+)CD27^(+)B cells,while the number of CD19^(+)CD27^(+)IL-10^(+)and CD19^(+)CD27^(+)Tim-3^(+)B cells increased significantly.In addition,Cur significantly inhibited the protein levels of Syk,p-Syk,Bcl-6,and CIN85,and increased BLNK and p-BLNK expression in colitis mice.CONCLUSION Cur could effectively alleviate DSS-induced colitis in mice by regulating memory B cells and the Bcl-6-Syk-BLNK signaling pathway.展开更多
The molecular basis of B cell receptor （BCR）-induced apoptosis during the negative selection of immature B cells is largely unknown. We use transitional immature B cells that are highly susceptible to BCR-induced ap...The molecular basis of B cell receptor （BCR）-induced apoptosis during the negative selection of immature B cells is largely unknown. We use transitional immature B cells that are highly susceptible to BCR-induced apoptosis to show that Pten is selectively required for BCR-mediated initiation of the mitochondrial death pathway. Specifically, deleting Pten, but not other pro-apoptotic molecules, abrogates BCR-elicited apoptosis and improves viability in wild-type immature B cells. We further identify a physiologically and significantly higher intracellular Pten level in immature B cells, as compared to mature B cells, which is responsible for low AKT activity and the propensity to- wards death in immature B cells. Restoration of AKT activity using a constitutive form of AKT or reduction of Pten to a level comparable with that seen in mature B cells rescues immature B cells from BCR-induced apoptosis. Thus, we provide evidence that Pten is an essential mediator of BCR-induced cell death, and that differential regulation of intracellular Pten levels determines whether BCR ligation promotes cell death or survival. Our findings provide a valuable insight into the mechanisms underlying negative selection and clonal deletion of immature B cells.展开更多
Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous subpopulations.Here,we showed that MZ B cells can be divid...Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous subpopulations.Here,we showed that MZ B cells can be divided into two distinct subpopulations according to their CD80 expression levels.CD80^(high)MZ B cells exhibited greater Ab-producing,proliferative,and IL-10-secreting capacities than did CD80^(low)MZ B cells.Notably,CD80^(high)MZ B cells survived 2-Gy whole-body irradiation,whereas CD80^(low)MZ B cells were depleted by irradiation and then repleted with one month after irradiation.Depletion of CD80^(low)MZ B cells led to accelerated development of type II collagen(CII)-induced arthritis upon immunization with bovine CII.CD80^(high)MZ B cells exhibited higher expression of genes involved in proliferation,plasma cell differentiation,and the antioxidant response.CD80^(high)MZ B cells expressed more autoreactive B cell receptors(BCRs)that recognized double-stranded DNA or CII,expressed more immunoglobulin heavy chain sequences with shorter complementarity-determining region 3 sequences,and included more clonotypes with no N-nucleotides or with B-1a BCR sequences than CD80^(low)MZ B cells.Adoptive transfer experiments showed that CD21^(+)CD23^(+)transitional 2 MZ precursors preferentially generated CD80^(low)MZ B cells and that a proportion of CD80^(low)MZ B cells were converted into CD80^(high)MZ B cells;in contrast,CD80^(high)MZ B cells stably remained CD80^(high)MZ B cells.In summary,MZ B cells can be divided into two subpopulations according to their CD80 expression levels,Ab-producing capacity,radioresistance,and autoreactivity,and these findings may suggest a hierarchical composition of MZ B cells with differential stability and BCR specificity.展开更多
The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown.Using a Pseudomonas aeruginosa-induced pneumonia model,we reported that IL-10-producing B cells(IL...The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown.Using a Pseudomonas aeruginosa-induced pneumonia model,we reported that IL-10-producing B cells(IL-10+B cells)play a key role in spontaneously resolving infection-mediated inflammation.Accumulated cytosolic reactive oxygen species(ROS)during inflammation were shown to drive IL-10+B-cell generation by remodeling one-carbon metabolism.Depletion of the enzyme serine hydroxymethyltransferase 1(Shmt1)led to inadequate one-carbon metabolism and decreased IL-10+B-cell production.Furthermore,increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine(SAM),altering histone H3 lysine 4 methylation(H3K4me)at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B cells.Therefore,the one-carbon metabolism-associated compound ethacrynic acid(EA)was screened and found to potentially treat infectious pneumonia by boosting IL-10+B-cell generation.Overall,these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.展开更多
The defense system of teleost fish organized on innate and adaptive immunity protects them against a wide variety of pathogenic microorganisms in the aquatic environment.Phagocytosis is one of the most effective defen...The defense system of teleost fish organized on innate and adaptive immunity protects them against a wide variety of pathogenic microorganisms in the aquatic environment.Phagocytosis is one of the most effective defense strategies against microbial challenge mainly performed by classical‘professional’phagocytes(including monocytes,macrophages and granulocytes).They contain,kill and process the internalized pathogens for antigen presentation by providing antigenic ligands to initiate activation and clonal expansion of T and B cells,which bridge the innate and adaptive immunity.The discovery of phagocytic B cells in teleost fish has broken the paradigm that primary vertebrate B cells are lack of phagocytosis of particulates,as well as led to the investigation of phagocytic activity of mammalian B-1 B cells.The active phagocytic,microbicidal capabilities and antigen presentation in teleost phagocytic B cell have demonstrated to be similar as professional phagocytes,providing a potential impact on development of new vaccination strategies to prevent and control infectious diseases.In this review,we aim to address current progress on the antimicrobial role of phagocytic B cells in teleost fish by comparing it with other professional phagocytes and mammalian B-1 B cells,and provide the application prospect of phagocytic B cells in developing vaccines as well as the prevention of fish diseases.展开更多
Traumatic injuries in the central nervous system,such as traumatic brain injury and spinal cord injury,are associated with tissue inflammation and the infiltration of immune cells,which simultaneously affect the self-...Traumatic injuries in the central nervous system,such as traumatic brain injury and spinal cord injury,are associated with tissue inflammation and the infiltration of immune cells,which simultaneously affect the self-renewal and differentiation of neural stem cells.Howeve r,the tissue repair process instigated by endogenous neural stem cells is incapable of restoring central nervous system injuries without external intervention.Recently,resident/peripheral immune cells have been demonstrated to exert significant effects on neural stem cells.Thus,the resto ration of traumatic injuries in the central nervous system by the immune intervention in neural stem cells represents a potential therapeutic method.In this review,we discuss the roles and possible mechanisms of immune cells on the selfrenewal and differentiation of neural stem cells along with the prognosis of central nervous system injuries based on immune intervention.Finally,we discuss remaining research challenges that need to be considered in the future.Further elucidation of these challenges will fa cilitate the successful application of neural stem cells in central nervous system injuries.展开更多
基金supported by grants from the National Natural Science Foundation of China (82070676)Jiangsu Provincial Medi-cal Innovation Center (CXZX202203)Jiangsu Provincial Medi-cal Key Laboratory (ZDXYS202201)。
文摘Background: Regulatory B cells(Bregs) is an indispensable element in inducing immune tolerance after liver transplantation. As one of the microRNAs(miRNAs), mi R-29a-3p also inhibits translation by degrading the target mRNA, and yet the relationship between Bregs and mi R-29a-3p has not yet been fully explored. This study aimed to investigate the impact of miR-29a-3p on the regulation of differentiation and immunosuppressive functions of memory Bregs(m Bregs) and ultimately provide potentially effective therapies in inducing immune tolerance after liver transplantation. Methods: Flow cytometry was employed to determine the levels of Bregs in peripheral blood mononuclear cells. TaqMan low-density array miRNA assays were used to identify the expression of different miRNAs, electroporation transfection was used to induce mi R-29a-3p overexpression and knockdown, and dual luciferase reporter assay was used to verify the target gene of miR-29a-3p. Results: In patients experiencing acute rejection after liver transplantation, the proportions and immunosuppressive function of m Bregs in the circulating blood were significantly impaired. mi R-29a-3p was found to be a regulator of m Bregs differentiation. Inhibition of miR-29a-3p, which targeted nuclear factor of activated T cells 5(NFAT5), resulted in a conspicuous boost in the differentiation and immunosuppressive function of m Bregs. The inhibition of mi R-29a-3p in CD19~+ B cells was capable of raising the expression levels of NFAT5, thereby promoting B cells to differentiate into m Bregs. In addition, the observed enhancement of differentiation and immunosuppressive function of m Bregs upon mi R-29a-3p inhibition was abolished by the knockdown of NFAT5 in B cells. Conclusions: mi R-29a-3p was found to be a crucial regulator for m Bregs differentiation and immunosuppressive function. Silencing mi R-29a-3p could be a potentially effective therapeutic strategy for inducing immune tolerance after liver transplantation.
文摘BACKGROUND The complexity of the immune microenvironment has an impact on the treatment of colorectal cancer(CRC),one of the most prevalent malignancies worldwide.In this study,multi-omics and single-cell sequencing techniques were used to investigate the mechanism of action of circulating and infiltrating B cells in CRC.By revealing the heterogeneity and functional differences of B cells in cancer immunity,we aim to deepen our understanding of immune regulation and provide a scientific basis for the development of more effective cancer treatment strategies.AIM To explore the role of circulating and infiltrating B cell subsets in the immune microenvironment of CRC,explore the potential driving mechanism of B cell development,analyze the interaction between B cells and other immune cells in the immune microenvironment and the functions of communication molecules,and search for possible regulatory pathways to promote the anti-tumor effects of B cells.METHODS A total of 69 paracancer(normal),tumor and peripheral blood samples were collected from 23 patients with CRC from The Cancer Genome Atlas database(https://portal.gdc.cancer.gov/).After the immune cells were sorted by multicolor flow cytometry,the single cell transcriptome and B cell receptor group library were sequenced using the 10X Genomics platform,and the data were analyzed using bioinformatics tools such as Seurat.The differences in the number and function of B cell infiltration between tumor and normal tissue,the interaction between B cell subsets and T cells and myeloid cell subsets,and the transcription factor regulatory network of B cell subsets were explored and analyzed.RESULTS Compared with normal tissue,the infiltrating number of CD20+B cell subsets in tumor tissue increased significantly.Among them,germinal center B cells(GCB)played the most prominent role,with positive clone expansion and heavy chain mutation level increasing,and the trend of differentiation into memory B cells increased.However,the number of plasma cells in the tumor microenvironment decreased significantly,and the plasma cells secreting IgA antibodies decreased most obviously.In addition,compared with the immune microenvironment of normal tissues,GCB cells in tumor tissues became more closely connected with other immune cells such as T cells,and communication molecules that positively regulate immune function were significantly enriched.CONCLUSION The role of GCB in CRC tumor microenvironment is greatly enhanced,and its affinity to tumor antigen is enhanced by its significantly increased heavy chain mutation level.Meanwhile,GCB has enhanced its association with immune cells in the microenvironment,which plays a positive anti-tumor effect.
基金National Natural Science Foundation of China,No.82001460the Natural Science Foundation of Zhejiang Province,No.LQ21H250001 (both to LS)。
文摘Accumulating evidence has demonstrated the involvement of B cells in neuroinflammation and neuroregeneration.However,the role of B cells in ischemic stroke remains unclear.In this study,we identified a novel phenotype of macrophage-like B cells in brain-infiltrating immune cells expressing a high level of CD45.Macrophage-like B cells chara cterized by co-expression of B-cell and macrophage markers,showed stronger phagocytic and chemotactic functions compared with other B cells and showed upregulated expression of phagocytosis-related genes.Gene Ontology analysis found that the expression of genes associated with phagocytosis,including phagosome-and lysosome-related genes,was upregulated in macrophage-like B cells.The phagocytic activity of macrophage-like B cells was ve rified by immunostaining and three-dimensional reconstruction,in which TREM2-labeled macrophage-like B cells enwrapped and internalized myelin debris after cerebral ischemia.Cell-cell interaction analysis revealed that macrophage-like B cells released multiple chemokines to recruit peripheral immune cells mainly via CCL pathways.Single-cell RNA sequencing showed that the transdiffe rentiation to macrophage-like B cells may be induced by specific upregulation of the transcription factor CEBP fa mily to the myeloid lineage and/or by downregulation of the transcription factor Pax5 to the lymphoid lineage.Furthermore,this distinct B cell phenotype was detected in brain tissues from mice or patients with traumatic brain injury,Alzheimer’s disease,and glioblastoma.Overall,these results provide a new perspective on the phagocytic capability and chemotactic function of B cells in the ischemic brain.These cells may serve as an immunotherapeutic target for regulating the immune response of ischemic stroke.
基金This project was supported by the National Natural Science Foundation of China(No.82000658,No.81770686,and No.81970591)and Huazhong University of Science and Technology research funds for self-dependent innovation(No.2017KFYXJJ101).
文摘Objective:Several studies indicated that tonsillectomy can improve the prognosis of patients with immunoglobulin A nephropathy(IgAN).However,the relationship between tonsillar immunity and IgAN is still unclear.Methods:A total of 14 IgAN patients were recruited in the current study from May 2015 to April 2016 in Tongji Hospital.B cells,dendritic cells(DCs),and IgAl positive cells in human tonsils were detected using immunofluorescence and immunohistochemistry.Correlations between these cells and clinicopathologic features were evaluated.
基金supported by grants from the National Science and Technology Major Project for Infectious Diseases Control during the 11th Five-Year Plan(2008ZX10002-012 and 2008ZX10002-013)the 12th Five-Year Plan(2012ZX10002003)
文摘BACKGROUND： Chronic hepatitis C virus （HCV） infection causes the skewing and activation of B cell subsets, but the characteristics of IgG＋ B cells in patients with chronic hepa- titis C （CHC） infection have not been thoroughly elucidated. CD4＋CXCR5＋ follicular helper T （Tfh） cells, via interleukin （IL）-21 secretion, activate B cells. However, the role of CD4＋CXCR5＋ T cells in the activation ofIgG＋ B cells in CHC patients is not clear. METHODS： The frequency of IgG＋ B cells, including CD27-IgG＋ B and CD27＋IgG＋ B cells, the expression of the activation markers （CD86 and CD95） in IgG＋ B cells, and the percentage of circu- lating CD4＋CXCR5＋ T cells were detected by flow cytometry in CHC patients （n=70） and healthy controls （n=25）. The con- centrations of serum IL-21 were analyzed using ELISA. The role of CD4＋CXCR5＋ T cells in the activation of IgG＋ B cells was investigated using a co-culture system. RESULTS： A significantly lower proportion of CD27＋IgG＋ B cells with increased expression of CD86 and CD95 was observed in CHC patients. The expression of CD95 was negatively correlated with the percentage of CD27＋IgG＋ B cells, and it contributed to CD27＋IgG＋ B cell apoptosis. Circulating CD4＋CXCR5＋ T cells and serum IL-21 were significantly increased in CHC patients. Moreover, circulating CD4＋CXCR5＋ T cells from CHC patients induced higher expressions of CD86 and CD95 in CD27＋IgG＋ B cells in a co-culture system; the blockade of the IL-21 decreased the expression levels of CD86 and CD95 in CD27＋IgG＋ B cells.CONCLUSIONS： HCV infection increased the frequency of CD4＋CXCR5＋ T cells and decreased the frequency of CD27＋IgG＋ B cells. CD4＋CXCR5＋ T cells activated CD27＋IgG＋ B cells via the secretion of IL-21.
文摘Objective： To observe the effect of the artesunate （ART） on cellular proliferation in vitro, to search for the possible anti-tumor mechanism of ART on endometrial carcinoma at the molecular level and to provide the experimental and theoretical foundations for the clinical applications of ART. Methods： The cell proliferation was observed by microscope; MTT was used to examine the effects of ART on proliferation of HEC-1B cells, and flow cytometric analysis was used to detect cell cycle and apoptosis. The human endometrial carcinoma HEC-1B cells were conventionally cultured; ART was administered with a concentration of 40 μg/ml before the total RNA were extracted, mRNA expression of Survivin, Caspase-3, N-Cadherin, E-Cadherin, Fibronectinl and Cox-2 were detected using RT-PCR. Results： ART reduced proliferation in human endometrial carcinoma cell line HEC-1B in a dose- and time-dependent effect. The cells of G0/G1 stage were significantly increased （P〈0.05）, but the cells of G2/M stages were significantly decreased （P〈0.05）, so it has shown that the cell cycle was probably blocked in G0/G1 stage. After intervention with ART at 20 and 80 μg/ml for 48 h, cellular apoptosis rate respectively was （36.42±0.77）% and （11.77±0.58）%, and the difference was statistically significant compared with the control （[6.64±0.191%, P〈0.01）. The expression of Cox-2 mRNA in the ART group was lower than those of control group, yet the expression of Caspase-3 and E-Cadherin mRNA in the ART group was higher than those of control group. Conclusion： ART can inhibit HEC-1B cell growth and proliferation in a dose- and time-dependent manner. Furthermore, ART can induce apoptosis in a dose-dependent manner. ART is able to downregulate Cox-2 mRNA expression and to upregulate E-Cadherin and Caspase-3 mRNA expression. So we can conclude that ART could induce the endometrial carcinoma HEC-1B cell apoptosis and inhibit tumor cell proliferation.
基金Supported by the National Natural Science Foundation of China(No.81470664No.81670887No.81700875)
文摘AIM： To investigate the association between IL-10-producing regulatory B（B10） cells and the clinical features of thyroid-associated orbitopathy（TAO）. METHODS： A total of 30 patients with TAO were recruited at Zhongshan Ophthalmic Center from May 2015 to December 2015. Peripheral blood mononuclear cells（PBMCs） were separated from blood samples of 30 TAO patients and 16 healthy controls and stimulated with CD40 ligand and CpG for 48h. The frequency of IL-10＋ B cells was examined by flow cytometry and the correlation between the frequency of IL-10＋ B cells and clinical features of TAO was analyzed by SPSS. RESULTS： The frequency of IL-10＋ B cells among CD19＋ B cells in TAO patients was significantly lower than in healthy controls（TAO： 4.66%±1.88% vs healthy control： 6.82%±2.40%, P〈0.01）. The frequency of IL-10＋ B cells showed a positive correlation with disease activity of TAO measured by Clinical Activity Score（CAS）（r=0.50, P〈0.01）, and became higher in TAO patients with family history of Graves＇ disease（GD）（P=0.04）. CONCLUSION： The decrease of the frequency of IL-10＋ B cells in TAO patients indicates the deficiency of B10 cells in TAO, and the positive association with disease activity suggests its important role in TAO inflammation regulation.
基金Supported by the Thailand Research Fund,No.RTA6280004the Grant for Chula Research Scholar,No.CU-GRS-61-07-30-02+1 种基金Second Century Fund(C2F),Chulalongkorn Universitythe Center of Excellence in Hepatitis and Liver Cancer,Faculty of Medicine,Chulalongkorn University。
文摘BACKGROUND Recent evidence has indicated the role of B cells and B cell-activating factor(BAFF)in the development of hepatocellular carcinoma(HCC).AIM To characterize circulating BAFF receptor expression and B cell subpopulations in patients with hepatitis B virus(HBV)-related HCC.METHODS Peripheral blood samples collected from 41 patients with chronic HBV infection(25 patients without HCC and 16 patients with HCC)and 9 healthy controls were assessed for BAFF receptors[BAFF-R(B cell-activating factor receptor),transmembrane activator and cyclophilin ligand interactor,B-cell maturation antigen]and B cell subpopulations by multicolor flow cytometry.RESULTS The frequency of BAFF-R expressing B cells to total B cells was significantly lower in patients with HCC(3.39%±2.12%)compared with the non-HCC group(5.37%±1.90%)and healthy controls(6.23%±2.32%),whereas there was no difference in transmembrane activator and cyclophilin ligand interactor and Bcell maturation antigen.The frequencies of CD27+Ig D+memory B cells,CD27+Ig Dclass-switched memory B cells and plasmablasts were significantly lower in the patients with HCC compared to patients without HCC(1.23±1.17 vs 3.09±1.55,P=0.001,0.60±0.44 vs 1.69±0.86,P<0.0001 and 0.16±0.12 vs 0.37±0.30,P=0.014,respectively).However,the ratio of na?ve and transitional B cell did not differ significantly between the three groups.In addition,decreased BAFF-R expression on B cells was significantly correlated with large tumor size and advanced tumor stage.CONCLUSION Our data demonstrated BAFF-R expression was reduced in B cells that involved with the frequencies of B cells maturation in patients with HCC.The depletion of BAFF-R might play an important role in the development of HCC in patients with chronic HBV infection.
基金Supported by Francesca Romana Delvecchio is supported by Cancer Research UK Post-doctoral fellowshipMichelle Goulart is supported by PCRF post-doctoral fellowshipRachel Elizabeth Ann Fincham is supported by PhD studentship awarded by Barts Charity(London,UK)and A^(*)STAR(Singapore)。
文摘Pancreatic cancer is a disease with high unmet clinical need.Pancreatic cancer is also characterised by an intense fibrotic stroma,which harbours many immune cells.Studies in both human and animal models have demonstrated that the immune system plays a crucial role in modulating tumour onset and progression.In human pancreatic ductal adenocarcinoma,high B-cell infiltration correlates with better patient survival.Hence,B cells have received recent interest in pancreatic cancer as potential therapeutic targets.However,the data on the role of B cells in murine models is unclear as it is dependent on the pancreatic cancer model used to study.Nevertheless,it appears that B cells do organise along with other immune cells such as a network of follicular dendritic cells(DCs),surrounded by T cells and DCs to form tertiary lymphoid structures(TLS).TLS are increasingly recognised as sites for antigen presentation,T-cell activation,Bcell maturation and differentiation in plasma cells.In this review we dissect the role of B cells and provide directions for future studies to harness the role of B cells in treatment of human pancreatic cancer.
基金Supported by 2011 Funding Project for Academic Human Resources Development(015000543111509)
文摘EBI2 is known as a kind of 7TM G protein-coupled receptors, and EBi2 gene is one of the most upregulated genes in Epstein-Barr virus （EBV） -infected lymphocytes. As a constitutively active receptor, EBI2 signals via Gai, and TM-II plays an important role in the signal transduct/on process. EBI2 is expressed mainly in mature, B cells and the expression level increases at the early stage of activation; subsequently, B cells are transferred into GC and the expression level is down-regulated. EBI2 can regulate independently and mediate synergistically the migration of B cell towards the extrafollicular areas and GC depending on chemo- kine receptors CXCR5 and CCR7 （EBII）. Differential expression of EBI2 receptor is conducive to accurate migration of B cells at different stages, thereby leading to appropriate irranunologic responses to T-dependent antigens. Recently, two research groups identified a specific oxysteml as the natural ligand for EBL2. Among all the oxysterols, 7α, 25-Dihydrexycholesteml （7a, 25-OHC） is the most effective ligand and activator, and EBI2-Oxysterol signal pathway plays an important role in adaptive immune responses. In addition, EBI2 is also closely related with specific kinds of autoimmune diseases, so it is considered as a negative regulator of the innate immune response in macrophages.
文摘Immunoglobulin (Ig) M production can be induced by the interaction of thymus-independent type-2 (TI-2) antigen (Ag) with B cell Ag receptors (BCRs) without the involvement of conventional T cells;for IgG production through the same process, however, a second signal is required. Previous studies have reported that invariant natural killer T (iNKT) cells may be responsible for the second signal involved in IgG production. In the present study, we addressed whether human iNKT cells could participate in the production of Ig against TI-2 Ag in vitro. Two major distinct subsets of human iNKT cells, CD4<sup>+</sup> CD8β<sup>-</sup> (CD4) and CD4<sup>-</sup> CD8β<sup>-</sup> [double negative (DN)] cells, were generated from peripheral blood monocytes from a healthy volunteer. BCR engagement, triggered by anti-IgM antibody stimulation, examined here as a model of BCR engagement triggered by TI-2 Ag, induced abundant IgM production by B cells. Both CD4 and DN iNKT cells reduced IgM production and conversely enhanced IgG production in a dose-dependent manner. In addition, IgG production by CD19<sup>+</sup>CD27<sup>-</sup> (naïve) and CD19<sup>+</sup>CD27<sup>+</sup> (memory) B cells was predominantly promoted by DNiNKT cells rather than CD4 iNKT cells;nevertheless, IgM production by both B cell subsets was similarly reduced by either subset of iNKT cells. These results suggest that the DN iNKT subsets may preferentially promote Ig class switching by B cells upon stimulation with TI-2 Ag.
文摘B cells play immunomodulatory roles mainly by presenting antigens and producing antibodies. In recent years, some B cells were shown to exhibit regulatory functions. This type of B cell was named regulatory B cells(Bregs). Bregs can mediate immune tolerance to inhibit excessive inflammatory responses and to accelerate recovery of infl ammation by producing interleukin 10 and/or transforming growth factor β1 and other inhibitory cytokines. Studies showed that Bregs play important roles in parasites, bacteria, and viral infections. This study reviews biological characteristics, functions, and microsignal regulation of Bregs and their mechanism in infectious diseases and related research progress.
基金support from the National Nature Science Foundation of China ( Grant No.81272341, 81401156)Research Program of Guangzhou Municipal Health Bureau Foundation of China (Grant No.20141A011085, 20141A011088)The PhD Start-up Fund Guangzhou Medical University (Grant No.2013C49)
文摘Objoctive： There is heterogeneity in the prognosis of gastric cancers staged according to the tumornodes-metastasis （TNM） system. This study evaluated the prognostic potential of an immune score system to supplement the TNM staging system. Mothodsg An immunohistochemical analysis was conducted to assess the density of T cells, B cells, and myeloid-derived suppressor cells （MDSCs） in cancer tissues from 100 stage IIIA gastric cancer patients; the expression of the high-mobility group protein B1 （HMGB1） was also evaluated in cancer cells. The relationship between the overall survival （OS）, disease-free survival （DFS）, and immunological parameters was analyzed.Results： An immune score system was compiled based on the prognostic role of the density ofT cells, B cells, MDSCs, and the expression of HMGB1 in cancer tissues. The median 5-year survival of this group of patient was 32%. However, the 5-year survival rates of 80.0%, 51.7%, 0%, 5.8%, and 0% varied among the patients with an immune score of 4 to those with an immune score of 0 based on the immune score system, respectively. Similarly, differences in DFS rates were observed among the immune score subgroups. Concluslons： An immune score system could effectively identify the prognostic heterogeneity within stage IliA gastric cancer patients, implying that this immune score system may potentially supplement the TNM staging system, and help in identifying a more homogeneous group of patients who on the basis of prognosis can undergo adjuvant therapy.
基金Supported by the National Natural Science Foundation of China,No.81760808Jiangxi University of Chinese Medicine Science and Technology Innovation Team Development Program,No.CXTD22008.
文摘BACKGROUND Immune dysfunction is the crucial cause in the pathogenesis of inflammatory bowel disease(IBD),which is mainly related to lymphocytes(T or B cells,including memory B cells),mast cells,activated neutrophils,and macrophages.As the precursor of B cells,the activation of memory B cells can trigger and differentiate B cells to produce a giant variety of inducible B cells and tolerant B cells,whose dysfunction can easily lead to autoimmune diseases,including IBD.AIM To investigate whether or not curcumin(Cur)can alleviate experimental colitis by regulating memory B cells and Bcl-6-Syk-BLNK signaling.METHODS Colitis was induced in mice with a dextran sulphate sodium(DSS)solution in drinking water.Colitis mice were given Cur(100 mg/kg/d)orally for 14 consecutive days.The colonic weight,colonic length,intestinal weight index,occult blood scores,and histological scores of mice were examined to evaluate the curative effect.The levels of memory B cells in peripheral blood of mice were measured by flow cytometry,and IL-1β,IL-6,IL-10,IL-7A,and TNF-αexpression in colonic tissue homogenates were analyzed by enzyme-linked immunosorbent assay.Western blot was used to measure the expression of Bcl-6,BLNK,Syk,and other signaling pathway related proteins.RESULTS After Cur treatment for 14 d,the body weight,colonic weight,colonic length,colonic weight index,and colonic pathological injury of mice with colitis were ameliorated.The secretion of IL-1β,IL-6,TNF-α,and IL-7A was statistically decreased,while the IL-35 and IL-10 levels were considerably increased.Activation of memory B cell subsets in colitis mice was confirmed by a remarkable reduction in the expression of IgM,IgG,IgA,FCRL5,CD103,FasL,PD-1,CD38,and CXCR3 on the surface of CD19^(+)CD27^(+)B cells,while the number of CD19^(+)CD27^(+)IL-10^(+)and CD19^(+)CD27^(+)Tim-3^(+)B cells increased significantly.In addition,Cur significantly inhibited the protein levels of Syk,p-Syk,Bcl-6,and CIN85,and increased BLNK and p-BLNK expression in colitis mice.CONCLUSION Cur could effectively alleviate DSS-induced colitis in mice by regulating memory B cells and the Bcl-6-Syk-BLNK signaling pathway.
文摘The molecular basis of B cell receptor （BCR）-induced apoptosis during the negative selection of immature B cells is largely unknown. We use transitional immature B cells that are highly susceptible to BCR-induced apoptosis to show that Pten is selectively required for BCR-mediated initiation of the mitochondrial death pathway. Specifically, deleting Pten, but not other pro-apoptotic molecules, abrogates BCR-elicited apoptosis and improves viability in wild-type immature B cells. We further identify a physiologically and significantly higher intracellular Pten level in immature B cells, as compared to mature B cells, which is responsible for low AKT activity and the propensity to- wards death in immature B cells. Restoration of AKT activity using a constitutive form of AKT or reduction of Pten to a level comparable with that seen in mature B cells rescues immature B cells from BCR-induced apoptosis. Thus, we provide evidence that Pten is an essential mediator of BCR-induced cell death, and that differential regulation of intracellular Pten levels determines whether BCR ligation promotes cell death or survival. Our findings provide a valuable insight into the mechanisms underlying negative selection and clonal deletion of immature B cells.
基金supported by National Research Foundation of Korea grant funded by the Korea government(MSIT)(2023R1A2C2004510)Korea Basic Science Institute(National Research Facilities and Equipment Center)grant(2020R1A6C101A191)of the Ministry of Education(Korea)the BK21 FOUR Program(Graduate School Innovation)of Sungkyunkwan University.
文摘Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous subpopulations.Here,we showed that MZ B cells can be divided into two distinct subpopulations according to their CD80 expression levels.CD80^(high)MZ B cells exhibited greater Ab-producing,proliferative,and IL-10-secreting capacities than did CD80^(low)MZ B cells.Notably,CD80^(high)MZ B cells survived 2-Gy whole-body irradiation,whereas CD80^(low)MZ B cells were depleted by irradiation and then repleted with one month after irradiation.Depletion of CD80^(low)MZ B cells led to accelerated development of type II collagen(CII)-induced arthritis upon immunization with bovine CII.CD80^(high)MZ B cells exhibited higher expression of genes involved in proliferation,plasma cell differentiation,and the antioxidant response.CD80^(high)MZ B cells expressed more autoreactive B cell receptors(BCRs)that recognized double-stranded DNA or CII,expressed more immunoglobulin heavy chain sequences with shorter complementarity-determining region 3 sequences,and included more clonotypes with no N-nucleotides or with B-1a BCR sequences than CD80^(low)MZ B cells.Adoptive transfer experiments showed that CD21^(+)CD23^(+)transitional 2 MZ precursors preferentially generated CD80^(low)MZ B cells and that a proportion of CD80^(low)MZ B cells were converted into CD80^(high)MZ B cells;in contrast,CD80^(high)MZ B cells stably remained CD80^(high)MZ B cells.In summary,MZ B cells can be divided into two subpopulations according to their CD80 expression levels,Ab-producing capacity,radioresistance,and autoreactivity,and these findings may suggest a hierarchical composition of MZ B cells with differential stability and BCR specificity.
基金supported by the General Program of the National Natural Science Foundation of China(81971493,81771736)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(82121002)+2 种基金Major Program of National Natural Science Foundation of China(821300501,82330053)Shanghai Rising-Star Program(20QA1407900)Innovative Research Team of High-level Local Universities in Shanghai.
文摘The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown.Using a Pseudomonas aeruginosa-induced pneumonia model,we reported that IL-10-producing B cells(IL-10+B cells)play a key role in spontaneously resolving infection-mediated inflammation.Accumulated cytosolic reactive oxygen species(ROS)during inflammation were shown to drive IL-10+B-cell generation by remodeling one-carbon metabolism.Depletion of the enzyme serine hydroxymethyltransferase 1(Shmt1)led to inadequate one-carbon metabolism and decreased IL-10+B-cell production.Furthermore,increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine(SAM),altering histone H3 lysine 4 methylation(H3K4me)at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B cells.Therefore,the one-carbon metabolism-associated compound ethacrynic acid(EA)was screened and found to potentially treat infectious pneumonia by boosting IL-10+B-cell generation.Overall,these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.
基金supported by the National Natural Science Foundation of China(32102827,31972818,31528019)China Postdoctoral Science Foundation(2019M662959)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2019A1515110987)Special fund for promoting economic development(for modern fishery development)of Guangdong Province(grant number 2019A4).
文摘The defense system of teleost fish organized on innate and adaptive immunity protects them against a wide variety of pathogenic microorganisms in the aquatic environment.Phagocytosis is one of the most effective defense strategies against microbial challenge mainly performed by classical‘professional’phagocytes(including monocytes,macrophages and granulocytes).They contain,kill and process the internalized pathogens for antigen presentation by providing antigenic ligands to initiate activation and clonal expansion of T and B cells,which bridge the innate and adaptive immunity.The discovery of phagocytic B cells in teleost fish has broken the paradigm that primary vertebrate B cells are lack of phagocytosis of particulates,as well as led to the investigation of phagocytic activity of mammalian B-1 B cells.The active phagocytic,microbicidal capabilities and antigen presentation in teleost phagocytic B cell have demonstrated to be similar as professional phagocytes,providing a potential impact on development of new vaccination strategies to prevent and control infectious diseases.In this review,we aim to address current progress on the antimicrobial role of phagocytic B cells in teleost fish by comparing it with other professional phagocytes and mammalian B-1 B cells,and provide the application prospect of phagocytic B cells in developing vaccines as well as the prevention of fish diseases.
基金supported by the National Natural Science Foundation of China,Nos.82172527 and 81972138 (to LLW)。
文摘Traumatic injuries in the central nervous system,such as traumatic brain injury and spinal cord injury,are associated with tissue inflammation and the infiltration of immune cells,which simultaneously affect the self-renewal and differentiation of neural stem cells.Howeve r,the tissue repair process instigated by endogenous neural stem cells is incapable of restoring central nervous system injuries without external intervention.Recently,resident/peripheral immune cells have been demonstrated to exert significant effects on neural stem cells.Thus,the resto ration of traumatic injuries in the central nervous system by the immune intervention in neural stem cells represents a potential therapeutic method.In this review,we discuss the roles and possible mechanisms of immune cells on the selfrenewal and differentiation of neural stem cells along with the prognosis of central nervous system injuries based on immune intervention.Finally,we discuss remaining research challenges that need to be considered in the future.Further elucidation of these challenges will fa cilitate the successful application of neural stem cells in central nervous system injuries.
