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
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:The study of regulatory B cells(Bregs)in systemic lupus erythematosus(SLE)has been in full swing in recent years,but the number and function of Bregs in SLE patients have also present quite contradictory re...Background:The study of regulatory B cells(Bregs)in systemic lupus erythematosus(SLE)has been in full swing in recent years,but the number and function of Bregs in SLE patients have also present quite contradictory results.Therefore,we conducted a meta-analysis to verify the changes in Bregs in active SLE.Methods:We identified studies reporting the proportions of Bregs in SLE patients by searching Pubmed,Embase,Web of Science,Cochrane and CNKI.Due to the degree of heterogeneity is very high,we used a random effects model to assess the mean differences in percentages of Bregs between active SLE and controls.Then,sensitivity analysis and subgroup analysis were performed to verify potential sources of heterogeneity.Results:Seven eligible articles involving 301 active SLE patients and 218 controls were included in the meta-analysis.The pooled percentages of Bregs were found no significant difference between active SLE patients and healthy controls[0.259,(−1.150,1.668),p=0.719],with great heterogeneity(I2=97.5%).The result of sensitivity analysis showed that exclusion of any single study or single article did not materially resolve the heterogeneity,but after excluding the article conducted by Cai X and his colleagues,the percentages of Bregs were significantly higher in active SLE than those in controls[1.394,(0.114,2.675),p=0.033].The results of subgroup analysis revealed that when the disease activity was judged by SLEDAI score≥5,the percentages of Bregs were significantly lower in the SLE groups than in the control groups[-1.99,(-3.241,-0.739),p=0.002],but when the threshold of SLEDAI score≥6 chosen for active SLE,the percentages of Bregs were significantly increased in the SLE groups[2.546,(1.333,3.759),p<0.001].Meanwhile,other subgroup analysis based on the different phenotypes of Bregs,diagnostic criteria,enrolled research countries,treatment status,and organ involvement did not differ in proportion of Bregs between SLE patients and controls.Conclusions:The study implies that Bregs may play a role in the pathogenesis of active SLE,and the thresholds of SLEDAI score to distinguish between active and inactive SLE patients are important factors affecting the percentages of Bregs.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
B cells are generally considered to be positive regulators of the immune response because of their capability to produce antibodies, including autoantibodies. The production of antibodies facilitates optimal CD4＋ T-c...B cells are generally considered to be positive regulators of the immune response because of their capability to produce antibodies, including autoantibodies. The production of antibodies facilitates optimal CD4＋ T-cell activation because B cells serve as antigen-presenting cells and exert other modulatory functions in immune responses. However, certain B cells can also negatively regulate the immune response by producing regulatory cytokines and directly interacting with pathogenic T cells via cell-to-cell contact. These types of B Cells are defined as regulatory B （Breg） cells. The regulatory function of Breg cells has been demonstrated in mouse models of inflammation, cancer, transplantation, and particularly in autoimmunity. In this review, we focus on the recent advances that lead to the understanding of the development and function of Breg cells and the implications of B cells in human autoimmune diseases.展开更多
Regulatory B cells(Bregs)suppress and reduce autoimmune pathology.However,given the variety of Breg subsets,the role of Bregs in the pathogenesis of type 1 diabetes is still unclear.Here,we dissect this fundamental me...Regulatory B cells(Bregs)suppress and reduce autoimmune pathology.However,given the variety of Breg subsets,the role of Bregs in the pathogenesis of type 1 diabetes is still unclear.Here,we dissect this fundamental mechanism.We show that natural protection from type 1 diabetes in nonobese diabetic(NOD)mice is associated with increased numbers of IL-10-producing B cells,while development of type 1 diabetes in NOD mice occurs in animals with compromised IL-10 production by B cells.However,B cells from diabetic mice regain IL-10 function if activated by the innate immune receptor TLR4 and can suppress insulin-specific CD8 T cells in a dendritic cell(DC)-dependent,IL-10-mediated fashion.Suppression of CD8 T cells is reliant on B-cell contact with DCs.This cell contact results in deactivation of DCs,inducing a tolerogenic state,which in turn can regulate pathogenic CD8 T cells.Our findings emphasize the importance of DC–Breg interactions during the development of type 1 diabetes.展开更多
Individuals infected with human immunodeficiency virus type-1(HIV-1)usually show a general dysregulation and hyper-activation of the immune system.A direct influence of HIV-1 particles on B-cell phenotypes and functio...Individuals infected with human immunodeficiency virus type-1(HIV-1)usually show a general dysregulation and hyper-activation of the immune system.A direct influence of HIV-1 particles on B-cell phenotypes and functions has been previously described.However,the consequences of B-cell dysregulation are still poorly understood.We evaluated the phenotypic changes in primary B cells after direct contact with HIV-1 particles in comparison with different types of stimuli.The functionality of treated B cells was challenged in co-culture experiments with autologous CD4+and CD8+T cells.We demonstrated that HIV-1 induces a phenotypic change in B cells towards a regulatory B-cell phenotype,showing a higher level of IL-10,TGF-β1,EBI3 or IL-12(p35)mRNA expression and acquiring an immunosuppressive profile.The acquisition of a Breg phenotype was confirmed by co-culture experiments where HIVtreated B cells reduced the proliferation and the TNFαproduction of CD4+or CD8+T cells.This suppressive ability of HIV-treated B cells was dependent on cell-to-cell contact between these B cells and effector cells.To our knowledge,these data provide the first evidence that HIV-1 can directly induce a regulatory B cell-like immunosuppressive phenotype,which could have the ability to impair specific immune responses.This dysregulation could constitute one of the mechanisms underlying unsuccessful efforts to develop an efficient vaccine against HIV-1.展开更多
Objective:To explore the balance of peripheral blood T helper 17 cells/regulatory T cell(Th17/Treg)ratio and the polarization ratio of M1 and M2 macrophages in lower extremity arteriosclerosis obliterans(ASO).Methods:...Objective:To explore the balance of peripheral blood T helper 17 cells/regulatory T cell(Th17/Treg)ratio and the polarization ratio of M1 and M2 macrophages in lower extremity arteriosclerosis obliterans(ASO).Methods:A rat model of lower extremity ASO was established,and blood samples from patients with lower extremity ASO before and after surgery were obtained.ELISA was used to detect interleukin 6(IL-6),IL-10,and IL-17.Real-time RCR and Western blot analyses were used to detect Foxp3,IL-6,IL-10,and IL-17 expression.Moreover,flow cytometry was applied to detect the Th17/Treg ratio and M1/M2 ratio.Results:Compared with the control group,the iliac artery wall of ASO rats showed significant hyperplasia,and the concentrations of cholesterol and triglyceride were significantly increased(P<0.01),indicating the successful establishment of ASO.Moreover,the levels of IL-6 and IL-17 in ASO rats were pronouncedly increased(P<0.05),while the IL-10 level was significantly decreased(P<0.05).In addition to increased IL-6 and IL-17 levels,the mRNA and protein levels of Foxp3 and IL-10 in ASO rats were significantly decreased compared with the control group.The Th17/Treg and M1/M2 ratios in the ASO group were markedly increased(P<0.05).These alternations were also observed in ASO patients.After endovascular surgery(such as percutaneous transluminal angioplasty and arterial stenting),all these changes were significantly improved(P<0.05).Conclusions:The Th17/Treg and M1/M2 ratios were significantly increased in ASO,and surgery can effectively improve the balance of Th17/Treg,and reduce the ratio of M1/M2,and the expression of inflammatory factors.展开更多
Recent studies indicated that regulatory B cells(Bregs)and nuclear factor erythroid 2-related factor 2(Nrf2)antioxidant signaling pathway play important roles in the pathogenesis of chronic graft-versus-host disease(c...Recent studies indicated that regulatory B cells(Bregs)and nuclear factor erythroid 2-related factor 2(Nrf2)antioxidant signaling pathway play important roles in the pathogenesis of chronic graft-versus-host disease(cGVHD).Mangiferin(MA),a polyphenol compound,has been reported to activate Nrf2/antioxidant-responsive element(ARE)signaling pathway.This study was aimed to investigate the effects of MA on Bregs and Nrf2 antioxidant signaling in murine splenic mononuclear cells(MNCs)in vitro.Our results revealed that MA could increase the Bregs level in murine splenic MNCs.Moreover,MA up-regulated the expression of Bregs-associated immunosuppressive factor interleukin-10(IL-10)by activating the Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)and extracellular signal-regulated kinase(ERK)signaling in murine splenic MNCs.Meanwhile,MA inhibited the proinflammatory cytokines IL-2 and interferon-y(INF-y)at both mRNA and protein levels.MA also enhanced the transcription and protein expression of Nrf2 and NADPH quinine oxidoreductase 1(NQOl),whereas decreased that of Kelch-like ECH-associated protein 1(Keapl)in murine splenic MNCs.Moreover,MA promoted the proliferation and inhibited the apoptosis of murine splenic MNCs.These results suggested that MA exerts immunosuppressive effects by upregulating the Bregs level,activating the Nrf2 antioxidant pathway,and inhibiting the expression of pro-immunoinflammatory factors.MA,as a natural immunomodulatory and anti-inflammatory agent,may have a potential role in the prophylaxis and treatment of cGVHD.展开更多
Innate-like B cells （ILBs） are heterogeneous populations of unconventional B cells with innate sensing and responding properties. ILBs in mice are composed of B1 cells, marginal zone （MZ） B cells and other related...Innate-like B cells （ILBs） are heterogeneous populations of unconventional B cells with innate sensing and responding properties. ILBs in mice are composed of B1 cells, marginal zone （MZ） B cells and other related B cells. ILBs maintain natural IgM levels at steady state, and after innate activation, they can rapidly acquire immune regulatory activities through the secretion of natural IgM and IL-IO. Thus, ILBs constitute an important source of IL-lO-producing regulatory B cells （Bregs）, which have been shown to play critical roles in autoimmunity, inflammation and infection. The present review highlights the latest advances in the field of ILBs and focuses on their regulatory functions. Understanding the regulatory activities of ILBs and their underlying mechanisms could open new avenues in manipulating their functions in inflammatory, infectious and other relevant diseases.展开更多
Pancreatic islet transplantation is a minimally invasive procedure aiming to reverse the effects of insulin deficiency in patients with type 1 diabetes(T1D)by transplanting pancreatic beta cells.Overall,pancreatic isl...Pancreatic islet transplantation is a minimally invasive procedure aiming to reverse the effects of insulin deficiency in patients with type 1 diabetes(T1D)by transplanting pancreatic beta cells.Overall,pancreatic islet transplantation has improved to a great extent,and cellular replacement will likely become the mainstay treatment.We review pancreatic islet transplantation as a treatment for T1D and the immunological challenges faced.Published data demonstrated that the time for islet cell transfusion varied between 2 and 10 h.Approximately 54%of the patients gained insulin independence at the end of the first year,while only 20%remained insulin-free at the end of the second year.Eventually,most transplanted patients return to using some form of exogenous insulin within a few years after the transplantation,which imposed the need to improve immunological factors before transplantation.We also discuss the immunosuppressive regimens,apoptotic donor lymphocytes,anti-TIM-1 antibodies,mixed chimerism-based tolerance induction,induction of antigen-specific tolerance utilizing ethylene carbodiimide-fixed splenocytes,pretransplant infusions of donor apoptotic cells,B cell depletion,preconditioning of isolated islets,inducing local immunotolerance,cell encapsulation and immunoisolation,using of biomaterials,immunomodulatory cells,etc.展开更多
The balance between immune effector cells and immunosuppressive cells and how this regulates the tumor microenvironment has been well described.A significant contribution of immune regulatory cells,including regulator...The balance between immune effector cells and immunosuppressive cells and how this regulates the tumor microenvironment has been well described.A significant contribution of immune regulatory cells,including regulatory T cells,to tumor progression has been widely reported.An emerging body of evidence has recently recognized a role for B cells in modulating the immune response to tumors and lymphoid malignancies.Regulatory B cells(Bregs)are a newly designated subset of B cells that have been shown to play a pivotal role in regulating immune responses involved in inflammation,autoimmunity and,more recently,cancer.Bregs can suppress diverse cell subtypes,including T cells,through the secretion of anti-inflammatory mediators,such as IL-10,and can facilitate the conversion of T cells to regulatory T cells,thus attenuating anti-tumor immune responses.Similar B-cell subpopulations have been reported to be recruited to the tumor but to acquire their immunosuppressive properties within the tumor bed and thereby attenuate anti-tumor immune responses.However,despite a pivotal role for Bregs in promoting inflammation and carcinogenesis,the phenotypic diversity of the cell surface markers that are unique to Bregs remains unclear in mice and humans.In this review,we summarize the characteristics of Bregs and review our current knowledge of Bregs and their inhibition of anti-tumor immune responses in murine tumor models and cancer patients.展开更多
Chronic hepatitis B(CHB)remains a global health problem.The persistence of hepatitis B surface antigen(HBsAg)in the blood for longer than 6 months after the initial infection is a sign of CHB.The therapeutic goal for ...Chronic hepatitis B(CHB)remains a global health problem.The persistence of hepatitis B surface antigen(HBsAg)in the blood for longer than 6 months after the initial infection is a sign of CHB.The therapeutic goal for the functional cure of CHB is the generation of antibodies against HBsAg.However,the adaptive immune response of patients with CHB cannot generate an efficient antiviral response.Many previous studies have evaluated T cell function and T cell therapy specifically designed to counter hepatitis B virus(HBV)infection.As one of the major components of adaptive immunity,B cells also display dysfunctions in anti-HBsAg antibody(HBsAb)production and antigen presentation.Patients with CHB have amplification of CD19^(+)CD10^(-)CD27^(-)CD21^(-)atypical memory B cell subsets and CD19^(+)CD24^(hi)CD38^(hi) regulatory B cells.Currently,no reviews have summarized specific B cell responses during CHB infection.Thus,in this study,we summarized B cell dysfunction during CHB progression and the potential mechanisms behind these dysfunctions to further our understanding of the mechanisms of adaptive immune response of B cells in the process of CHB development and help provide new methods and ideas for the treatment of CHB.展开更多
Calreticulin(CRT)is a multifunctional molecule in both intracellular and extracellular environment.We have previ-ously found that a recombinant CRT fragment(rCRT/39-272)could modulate T cell-mediated immunity in mice ...Calreticulin(CRT)is a multifunctional molecule in both intracellular and extracellular environment.We have previ-ously found that a recombinant CRT fragment(rCRT/39-272)could modulate T cell-mediated immunity in mice via activation and expansion of CD1dhiCD5+B cells as well as induction of CRT-specifi c regulatory antibodies.Anti-body secreting cells(ASCs)are terminally differentiated B cells responsible for producing antibodies to participate in positive immune response as well as immune regula-tion.In this study,we demonstrate that rCRT/39-272 dif-ferentiates murine CD1dhiCD5+B cells into ASCs mark-ed by increased expression of plasma cell-associated transcription factors and production of polyreactive antibodies against DNA and CRT in vitro.Intraperitoneal administration of rCRT/39-272 augmented differentiation of CD1dhiCD5+B cells into ASCs in naïve mice or mice with experimental autoimmune encephalomyelitis.Thus,we propose that ASC differentiation and subsequent an-tibody production of CD1dhiCD5+B cells are key steps in CRT-mediated immunoregulation on infl ammatory T cell responses.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.
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This work was supported by funding from the National Natural Science Foundation of China Grants[81760286].
文摘Background:The study of regulatory B cells(Bregs)in systemic lupus erythematosus(SLE)has been in full swing in recent years,but the number and function of Bregs in SLE patients have also present quite contradictory results.Therefore,we conducted a meta-analysis to verify the changes in Bregs in active SLE.Methods:We identified studies reporting the proportions of Bregs in SLE patients by searching Pubmed,Embase,Web of Science,Cochrane and CNKI.Due to the degree of heterogeneity is very high,we used a random effects model to assess the mean differences in percentages of Bregs between active SLE and controls.Then,sensitivity analysis and subgroup analysis were performed to verify potential sources of heterogeneity.Results:Seven eligible articles involving 301 active SLE patients and 218 controls were included in the meta-analysis.The pooled percentages of Bregs were found no significant difference between active SLE patients and healthy controls[0.259,(−1.150,1.668),p=0.719],with great heterogeneity(I2=97.5%).The result of sensitivity analysis showed that exclusion of any single study or single article did not materially resolve the heterogeneity,but after excluding the article conducted by Cai X and his colleagues,the percentages of Bregs were significantly higher in active SLE than those in controls[1.394,(0.114,2.675),p=0.033].The results of subgroup analysis revealed that when the disease activity was judged by SLEDAI score≥5,the percentages of Bregs were significantly lower in the SLE groups than in the control groups[-1.99,(-3.241,-0.739),p=0.002],but when the threshold of SLEDAI score≥6 chosen for active SLE,the percentages of Bregs were significantly increased in the SLE groups[2.546,(1.333,3.759),p<0.001].Meanwhile,other subgroup analysis based on the different phenotypes of Bregs,diagnostic criteria,enrolled research countries,treatment status,and organ involvement did not differ in proportion of Bregs between SLE patients and controls.Conclusions:The study implies that Bregs may play a role in the pathogenesis of active SLE,and the thresholds of SLEDAI score to distinguish between active and inactive SLE patients are important factors affecting the percentages of Bregs.
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.
文摘B cells are generally considered to be positive regulators of the immune response because of their capability to produce antibodies, including autoantibodies. The production of antibodies facilitates optimal CD4＋ T-cell activation because B cells serve as antigen-presenting cells and exert other modulatory functions in immune responses. However, certain B cells can also negatively regulate the immune response by producing regulatory cytokines and directly interacting with pathogenic T cells via cell-to-cell contact. These types of B Cells are defined as regulatory B （Breg） cells. The regulatory function of Breg cells has been demonstrated in mouse models of inflammation, cancer, transplantation, and particularly in autoimmunity. In this review, we focus on the recent advances that lead to the understanding of the development and function of Breg cells and the implications of B cells in human autoimmune diseases.
基金This work was funded by the Medical Research Council(UK)(MR/K021141/1 to FSW)LCDR was funded by a studentship from Cnpq(Conselho Nacional de Pesquisa,Brazil,grant#245609/2012-1).
文摘Regulatory B cells(Bregs)suppress and reduce autoimmune pathology.However,given the variety of Breg subsets,the role of Bregs in the pathogenesis of type 1 diabetes is still unclear.Here,we dissect this fundamental mechanism.We show that natural protection from type 1 diabetes in nonobese diabetic(NOD)mice is associated with increased numbers of IL-10-producing B cells,while development of type 1 diabetes in NOD mice occurs in animals with compromised IL-10 production by B cells.However,B cells from diabetic mice regain IL-10 function if activated by the innate immune receptor TLR4 and can suppress insulin-specific CD8 T cells in a dendritic cell(DC)-dependent,IL-10-mediated fashion.Suppression of CD8 T cells is reliant on B-cell contact with DCs.This cell contact results in deactivation of DCs,inducing a tolerogenic state,which in turn can regulate pathogenic CD8 T cells.Our findings emphasize the importance of DC–Breg interactions during the development of type 1 diabetes.
基金This work was partially supported by Ministry of Economy and Competitiveness ISCIII-FIS grants PI12/01763,PI12/00934 and PI15/00923co-financed by ERDF(FEDER)Funds from the European Commission,‘A way of making Europe’+3 种基金JL-A was supported by a Grant from IiSGMAP-S was supported by the Youth Employment Program co-financed by the Madrid community and FEDER FoundsRC-R was supported by the‘Miguel Servet’program(CPII13/00033)MP by the Spanish MICINN through the Ramón y Cajal(RYC-2009-05486).
文摘Individuals infected with human immunodeficiency virus type-1(HIV-1)usually show a general dysregulation and hyper-activation of the immune system.A direct influence of HIV-1 particles on B-cell phenotypes and functions has been previously described.However,the consequences of B-cell dysregulation are still poorly understood.We evaluated the phenotypic changes in primary B cells after direct contact with HIV-1 particles in comparison with different types of stimuli.The functionality of treated B cells was challenged in co-culture experiments with autologous CD4+and CD8+T cells.We demonstrated that HIV-1 induces a phenotypic change in B cells towards a regulatory B-cell phenotype,showing a higher level of IL-10,TGF-β1,EBI3 or IL-12(p35)mRNA expression and acquiring an immunosuppressive profile.The acquisition of a Breg phenotype was confirmed by co-culture experiments where HIVtreated B cells reduced the proliferation and the TNFαproduction of CD4+or CD8+T cells.This suppressive ability of HIV-treated B cells was dependent on cell-to-cell contact between these B cells and effector cells.To our knowledge,these data provide the first evidence that HIV-1 can directly induce a regulatory B cell-like immunosuppressive phenotype,which could have the ability to impair specific immune responses.This dysregulation could constitute one of the mechanisms underlying unsuccessful efforts to develop an efficient vaccine against HIV-1.
基金supported by Natural Science Foundation of Hainan Province(820MS135)Hainan Provincial Health Commission 2023 Provincial Key Clinical Discipline(Clinical Medical Center)Construction Unit Fund Project(Qiongwei Yihan[2022]No.341)Hainan Provincial Health Technology Innovation Joint Project(WSJK2024MS209).
文摘Objective:To explore the balance of peripheral blood T helper 17 cells/regulatory T cell(Th17/Treg)ratio and the polarization ratio of M1 and M2 macrophages in lower extremity arteriosclerosis obliterans(ASO).Methods:A rat model of lower extremity ASO was established,and blood samples from patients with lower extremity ASO before and after surgery were obtained.ELISA was used to detect interleukin 6(IL-6),IL-10,and IL-17.Real-time RCR and Western blot analyses were used to detect Foxp3,IL-6,IL-10,and IL-17 expression.Moreover,flow cytometry was applied to detect the Th17/Treg ratio and M1/M2 ratio.Results:Compared with the control group,the iliac artery wall of ASO rats showed significant hyperplasia,and the concentrations of cholesterol and triglyceride were significantly increased(P<0.01),indicating the successful establishment of ASO.Moreover,the levels of IL-6 and IL-17 in ASO rats were pronouncedly increased(P<0.05),while the IL-10 level was significantly decreased(P<0.05).In addition to increased IL-6 and IL-17 levels,the mRNA and protein levels of Foxp3 and IL-10 in ASO rats were significantly decreased compared with the control group.The Th17/Treg and M1/M2 ratios in the ASO group were markedly increased(P<0.05).These alternations were also observed in ASO patients.After endovascular surgery(such as percutaneous transluminal angioplasty and arterial stenting),all these changes were significantly improved(P<0.05).Conclusions:The Th17/Treg and M1/M2 ratios were significantly increased in ASO,and surgery can effectively improve the balance of Th17/Treg,and reduce the ratio of M1/M2,and the expression of inflammatory factors.
基金the National Natural Science Foundation of China(No.81470347,No.81974003)The authors would like to thank the Department of Central Laboratory,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan,China,for providing relevant experimental facilities and technical support.
文摘Recent studies indicated that regulatory B cells(Bregs)and nuclear factor erythroid 2-related factor 2(Nrf2)antioxidant signaling pathway play important roles in the pathogenesis of chronic graft-versus-host disease(cGVHD).Mangiferin(MA),a polyphenol compound,has been reported to activate Nrf2/antioxidant-responsive element(ARE)signaling pathway.This study was aimed to investigate the effects of MA on Bregs and Nrf2 antioxidant signaling in murine splenic mononuclear cells(MNCs)in vitro.Our results revealed that MA could increase the Bregs level in murine splenic MNCs.Moreover,MA up-regulated the expression of Bregs-associated immunosuppressive factor interleukin-10(IL-10)by activating the Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)and extracellular signal-regulated kinase(ERK)signaling in murine splenic MNCs.Meanwhile,MA inhibited the proinflammatory cytokines IL-2 and interferon-y(INF-y)at both mRNA and protein levels.MA also enhanced the transcription and protein expression of Nrf2 and NADPH quinine oxidoreductase 1(NQOl),whereas decreased that of Kelch-like ECH-associated protein 1(Keapl)in murine splenic MNCs.Moreover,MA promoted the proliferation and inhibited the apoptosis of murine splenic MNCs.These results suggested that MA exerts immunosuppressive effects by upregulating the Bregs level,activating the Nrf2 antioxidant pathway,and inhibiting the expression of pro-immunoinflammatory factors.MA,as a natural immunomodulatory and anti-inflammatory agent,may have a potential role in the prophylaxis and treatment of cGVHD.
基金This work was supported in part by grants from National Natural Science Foundation of China （31270961） and Shanghai Science and Technology Development Funds （12QA1403600）. The author would like to thank Mr Yiyuan Fang for his help with figure preparation and Mr Brian Mozeleski for his critical reading.
文摘Innate-like B cells （ILBs） are heterogeneous populations of unconventional B cells with innate sensing and responding properties. ILBs in mice are composed of B1 cells, marginal zone （MZ） B cells and other related B cells. ILBs maintain natural IgM levels at steady state, and after innate activation, they can rapidly acquire immune regulatory activities through the secretion of natural IgM and IL-IO. Thus, ILBs constitute an important source of IL-lO-producing regulatory B cells （Bregs）, which have been shown to play critical roles in autoimmunity, inflammation and infection. The present review highlights the latest advances in the field of ILBs and focuses on their regulatory functions. Understanding the regulatory activities of ILBs and their underlying mechanisms could open new avenues in manipulating their functions in inflammatory, infectious and other relevant diseases.
基金Supported by European Union-NextGenerationEU,through The National Recovery and Resilience Plan of the Republic of Bulgaria,No.BG-RRP-2.004-0008-C01.
文摘Pancreatic islet transplantation is a minimally invasive procedure aiming to reverse the effects of insulin deficiency in patients with type 1 diabetes(T1D)by transplanting pancreatic beta cells.Overall,pancreatic islet transplantation has improved to a great extent,and cellular replacement will likely become the mainstay treatment.We review pancreatic islet transplantation as a treatment for T1D and the immunological challenges faced.Published data demonstrated that the time for islet cell transfusion varied between 2 and 10 h.Approximately 54%of the patients gained insulin independence at the end of the first year,while only 20%remained insulin-free at the end of the second year.Eventually,most transplanted patients return to using some form of exogenous insulin within a few years after the transplantation,which imposed the need to improve immunological factors before transplantation.We also discuss the immunosuppressive regimens,apoptotic donor lymphocytes,anti-TIM-1 antibodies,mixed chimerism-based tolerance induction,induction of antigen-specific tolerance utilizing ethylene carbodiimide-fixed splenocytes,pretransplant infusions of donor apoptotic cells,B cell depletion,preconditioning of isolated islets,inducing local immunotolerance,cell encapsulation and immunoisolation,using of biomaterials,immunomodulatory cells,etc.
文摘The balance between immune effector cells and immunosuppressive cells and how this regulates the tumor microenvironment has been well described.A significant contribution of immune regulatory cells,including regulatory T cells,to tumor progression has been widely reported.An emerging body of evidence has recently recognized a role for B cells in modulating the immune response to tumors and lymphoid malignancies.Regulatory B cells(Bregs)are a newly designated subset of B cells that have been shown to play a pivotal role in regulating immune responses involved in inflammation,autoimmunity and,more recently,cancer.Bregs can suppress diverse cell subtypes,including T cells,through the secretion of anti-inflammatory mediators,such as IL-10,and can facilitate the conversion of T cells to regulatory T cells,thus attenuating anti-tumor immune responses.Similar B-cell subpopulations have been reported to be recruited to the tumor but to acquire their immunosuppressive properties within the tumor bed and thereby attenuate anti-tumor immune responses.However,despite a pivotal role for Bregs in promoting inflammation and carcinogenesis,the phenotypic diversity of the cell surface markers that are unique to Bregs remains unclear in mice and humans.In this review,we summarize the characteristics of Bregs and review our current knowledge of Bregs and their inhibition of anti-tumor immune responses in murine tumor models and cancer patients.
基金This work was supported by the National Natural Science Foundation of China(81874436 to Y.Gao,81673935 to X.Sun).
文摘Chronic hepatitis B(CHB)remains a global health problem.The persistence of hepatitis B surface antigen(HBsAg)in the blood for longer than 6 months after the initial infection is a sign of CHB.The therapeutic goal for the functional cure of CHB is the generation of antibodies against HBsAg.However,the adaptive immune response of patients with CHB cannot generate an efficient antiviral response.Many previous studies have evaluated T cell function and T cell therapy specifically designed to counter hepatitis B virus(HBV)infection.As one of the major components of adaptive immunity,B cells also display dysfunctions in anti-HBsAg antibody(HBsAb)production and antigen presentation.Patients with CHB have amplification of CD19^(+)CD10^(-)CD27^(-)CD21^(-)atypical memory B cell subsets and CD19^(+)CD24^(hi)CD38^(hi) regulatory B cells.Currently,no reviews have summarized specific B cell responses during CHB infection.Thus,in this study,we summarized B cell dysfunction during CHB progression and the potential mechanisms behind these dysfunctions to further our understanding of the mechanisms of adaptive immune response of B cells in the process of CHB development and help provide new methods and ideas for the treatment of CHB.
基金This study was supported by grants from PCSIRT(IRT1075)the National Natural Science Foundation of China(Grant Nos.31370908,31070781,and 31100633)+1 种基金the National Basic Research Program(973 Program)(No.2010CB529102)Foundation of Nature Science of Jiangsu Higher Education Institutions of China(11KJB180011).
文摘Calreticulin(CRT)is a multifunctional molecule in both intracellular and extracellular environment.We have previ-ously found that a recombinant CRT fragment(rCRT/39-272)could modulate T cell-mediated immunity in mice via activation and expansion of CD1dhiCD5+B cells as well as induction of CRT-specifi c regulatory antibodies.Anti-body secreting cells(ASCs)are terminally differentiated B cells responsible for producing antibodies to participate in positive immune response as well as immune regula-tion.In this study,we demonstrate that rCRT/39-272 dif-ferentiates murine CD1dhiCD5+B cells into ASCs mark-ed by increased expression of plasma cell-associated transcription factors and production of polyreactive antibodies against DNA and CRT in vitro.Intraperitoneal administration of rCRT/39-272 augmented differentiation of CD1dhiCD5+B cells into ASCs in naïve mice or mice with experimental autoimmune encephalomyelitis.Thus,we propose that ASC differentiation and subsequent an-tibody production of CD1dhiCD5+B cells are key steps in CRT-mediated immunoregulation on infl ammatory T cell responses.
