Abnormal expression of b10 cell frequencies: possible relation to pathogenesis and disease severity of aplastic anemia

SUMMARY OBJECTIVE: Aplastic anemia (AA) is an immune-mediated disease that destroys hematopoietic cells through activated T lymphocytes. B lymphocyte-mediated humoral immunity also plays an important role in the pathogenesis of AA. Regulatory B cell (Breg) subpopulation, which is defined as "B10", secretes interleukin 10 (IL-10). The objective of our experiment was to investigate whether the scale-down proportion of B10 cells in AA patients may play a key role in the pathogenesis. METHODS: A total of 38 AA patients (14 SAA patients and 24 NSAA patients) and 20 healthy control subjects were included. All subjects did not suffer from autoimmune diseases or any other diseases affecting the immune system, such as infectious diseases. Bone marrow mononuclear cells (PBMCs) were isolated and analyzed by Flow cytometry (FCM) and Immunofluorescence double-labeling assay. The relationship between the relative proportions of B10 and ProB10 and their associations to AA, as well as disease severity, were assessed by common clinical indicators and then examined. RESULTS: Our analyses revealed AA patients had significantly lower proportions of peripheral B10 and B10pro compared to healthy controls. SAA patients had a substantially lower percentage of B10 cells and B10pro cells compared to NSAA patients. In addition, B10 cells and B10pro cells were negatively correlated with absolute neutrophil counts, hemoglobin levels and platelet, and absolute reticulocyte counts in AA patients. CONCLUSIONS: The present study attempted to elucidate the potential role of the scale-down proportion of B10 cells in the pathogenesis of AA.

RESUMO OBJETIVO: A anemia aplástica (AA) é uma doença imunomediada que destrói células hematopoiéticas por meio dos linfócitos T ativados. A imunidade humoral mediada por linfócitos B também desempenha um papel importante na patogênese da AA. A subpopulação de células B reguladoras (Breg), que é definida como "B10", secreta interleucina 10 (IL-10). No experimento, investigou-se se a proporção reduzida de células B10 nos pacientes de AA pode desempenhar um papel-chave na patogênese. MÉTODOS: Um total de 38 pacientes de AA (14 pacientes de anemia aplástica grave e 24 pacientes de anemia aplástica não grave) e 20 indivíduos de controle saudáveis foram incluídos. Todos os indivíduos não sofriam de doenças autoimunes ou de quaisquer outras doenças que afetam o sistema imunológico, tais como doenças contagiosas. As células mononucleares da medula óssea (PBMCs) eram isoladas e analisadas por citometria de fluxo (FCM) e ensaio de dupla marcação por imunofluorescência. A relação entre as proporções relativas de células B10 e as células ProB10 e as suas associações à AA, assim como a gravidade da doença avaliada por indicadores clínicos comuns, foram examinadas. RESULTADOS: Nossas análises revelaram que os pacientes de AA têm proporções significativamente menores de células B10 e células ProB10 periféricas em comparação com indivíduos de controle saudáveis. Os pacientes de anemia aplástica grave tiveram uma percentagem substancialmente menor de células B10 e células B10pro em comparação com pacientes de anemia aplástica não grave. Além disso, as células B10 e B10pro foram negativamente correlacionadas com contagens absolutas de neutrófilos, níveis de hemoglobina e plaquetas e contagem de reticulócitos absolutos nos pacientes de AA. CONCLUSÕES: Além disso, o estudo presente tentou elucidar o papel imunorregulatório potencial das células B10 na patogênese da AA e fornecer uma nova estratégia para a aplicação de imunoterapia baseada na célula B para tratar a AA no futuro.

Low frequency of regulatory B-cells and increased CD4+ and CD8+ interferon-γ-producing cells in patients with tropical spastic paraparesis associated with human T-cell lymphotropic virus type

Abstract INTRODUCTION: Tropical spastic paraparesis/HTLV-1 associated myelopathy (TSP/HAM) is a disease caused by human T-cell lymphotropic virus type 1 (HTLV-I) that mainly infects CD4 T cells-for example, those of the CD4+CD25hiFOXP3+ [Treg] phenotype-where it inhibits forkhead box protein P3 (FOXP3) expression and promotes interferon-γ (IFN-γ) expression. However, the role it exerts on regulatory B cells (CD19+CD24hiCD38hi; Breg) is unknown. METHODS: The frequencies of Treg and Breg cells was evaluated and the Th1 profiles were assessed in TSP/HAM patients and healthy control subjects. RESULTS: Low percentages of Breg cells and high production of IFN-γ were observed in patients compared to those in healthy control subjects. CONCLUSIONS: The low percentage of Breg cells in patients and the increase in the frequency of Th1 cells suggest an imbalance in the control of the inflammatory response that contributes to the immunopathogenesis of TSP/HAM.

Level of Regulatory B Cells in Patients with Immune Thrombocytopenia and Its Clinical Significance / 中国实验血液学杂志

OBJECTIVE@#To investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia(ITP) and its clinical significance.@*METHODS@#A total of 40 ITP patients and 20 normal controls were enrolled in this study. The content of Breg, Th1, Th2, Th17 and Treg cells were detected by flow cytometry (FCM). The expression level of IL-10,TGF-β, CD40 and CD40L was detected by AimPlex Flow High Throughput Screening Technology.@*RESULTS@#The of Breg cells in ITP patients was significantly lower than that in normal controls (P<0.05)，the expression levels of IL-10,TGF-β and CD40L in ITP patients were also significantly lower than those in normal controls (P<0.05). The contents of Th1 cells in ITP patients were significantly higher than that in normal controls (P<0.05), whereas the contents of Th2, Th17 and Treg cells in ITP patients were significantly lower than those in normal controls (P<0.05).@*CONCLUSION@#The Breg cells may play an important role in the pathogenesis of ITP.

Expression of CD19B Cells and Involvement of Serum Breg in Pathogenesis of Immune Thrombocytopenia / 中国实验血液学杂志

OBJECTIVE@#To study the expression of CD19B cells in immune thrombocytopenia patients, and to analyze the involvement of serum Breg in the pathogenesis of ITP.@*METHODS@#A total of 68 ITP patients admitted in department of hematology in our hospital from August 2015 to August 2018 were selected and enrolled in ITP group. 30 healthy individuals who were admitted to physical examination center at the same time were selected and enrolled in control group. The expression of peripheral blood lymphocyte subsets CD19 and peripheral blood Breg cells were measured by flow cytometry. The difference between the ITP group and the control group was compared. The IL-10 mRNA and TGF-β1 mRNA levels were detected by RT-PCR. Correlations between the ratio of peripheral blood Breg cells and the expression of IL-10 mRNA and TGF-β1 mRNA in patients with immune thrombocytopenia, were analyzed.@*RESULTS@#Expression of CD19 in ITP group was significantly higher than that in control group. The difference between the two groups was statistically significant. Expression level of serum Breg cells in ITP group was lower than that in control group. IL-10 mRNA level in ITP group was significantly lower than that in control group. IL-10 mRNA level after treatment was significantly higher than that before treatment. In addition, TGF-β1 mRNA level in newly diagnosed ITP group was significantly higher than that in control group. After treatment, the TGF-β1 mRNA level was higher than that before treatment. The ratio of peripheral blood Breg cells positively correlated with IL-10 mRNA expression (r=0.968, P＜0.05), however, there was no correlation between peripheral blood Breg cell ratio and TGF-β1 mRNA expression (r=0.502, P＞0.05).@*CONCLUSION@#Expression of CD19 cells in ITP patients is increased. Breg cells may participate in the genesis of immune thrombocytopenia. The abnormal expression of Breg cells relates with the pathogenesis of immune thrombocytopenia.

Role of Interleukin-10-Expressing B Cells on the Pathophysiology of Chronic Sinusitis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Many kinds of inflammatory cells and cytokines are suggested to be related with pathophysiology of chronic rhinosinusitis with nasal polyp (CRSwNP), but its mechanism is not yet fully understood. In particular, little is known about the function and role of Interleukin-10 (IL-10) producing regulatory B cells. The aim of this study was to investigate the presence and function of B cells, especially IL-10-producing regulatory B cells, in the nasal polyp (NP) and nasal mucosa. SUBJECTS AND METHOD: Twenty patients with CRSwNP, 10 patients with chronic rhinosinusitis without nasal polyp (CRSsNP) and 10 control subjects were enrolled in this study. NP tissues and uncinate tissues were collected for analysis. Real-time polymerase chain reaction (RT-PCR), immunohistochemistry were performed to measure the expression levels of the selected inflammatory cytokines and inflammation-associated molecules. RESULTS: In the mucosal tissues of CRSsNP patients, the number of IL-10+ B cells was significantly lower than that of NP and control mucosa of CRSwNP patients. The number of IL-10+ B cells was significantly increased in the eosinophilic NP, non-eosinohilic NP, CRSsNP, and control groups. There was a significant positive correlation between the number of IL-10+ B cells and B cell activating factor (BAFF). CONCLUSION: The expression of IL-10+ B cells and BAFF was significantly increased in CRSwNP patients compared to CRSsNP patients and control mucosal tissues, and IL-10+ B cells were more significantly increased in eosinophilic tissues. These results indicate that regulatory B cells are involved in the pathophysiology of eosinophilic NP and that BAFF contributes to the production of regulatory B cells.

Analysis of Peripheral B Cell Subsets in Patients With Allergic Rhinitis

PURPOSE: Recent evidence suggests that B cells can both promote and inhibit the development and progression of allergic disease. However, the characteristics of B cell subsets in patients with allergic rhinitis (AR) have not been well documented. This study aimed to analyze the characteristics of B cell subsets in the peripheral blood of AR patients. METHODS: Forty-seven AR patients and 54 healthy controls were enrolled in this study, and the B cell subsets in peripheral blood of all subjects were analyzed by flow cytometry. Moreover, the serum total immunoglobulin E (IgE) and IgE concentrations secreted into the cultured peripheral blood mononuclear cells (PBMCs) were measured by using enzyme-linked immunosorbent assay. RESULTS: We found the peripheral blood of AR patients contained higher percentages of memory B cells, plasma cells, and CD19+CD24hiCD27+ regulatory B cells (Bregs) than those of age-matched healthy controls (P < 0.05), while the percentages of naïve B cells and CD19+CD24hiCD38hi Bregs were significantly lower in AR patients than in healthy individuals (P < 0.05). In addition, the serum total IgE and IgE concentrations secreted into the cultured PBMCs were elevated in AR patients than in the healthy controls (P < 0.05). CONCLUSIONS: Our findings indicate that AR patients were characterized by increase in terminally differentiated memory B cells or plasma cells and decreases in CD19+CD24hiCD38hi Breg cells in the peripheral blood.

The Role of B Cells in Transplantation Rejection / 대한이식학회지

B cells play a role in graft rejection via several mechanisms. Specifically, B cells produce high-affinity antibodies to alloantigens including allogeneic major histocompatibility complex (MHC) with the help of follicular helper T cells. B cells also function as antigen-presenting cells for alloreactive T cells, resulting in the activation of alloreactive T cells. Conversely, the frequency of regulatory B cells increases under inflammatory conditions and suppresses the rejection process. Here, the differential roles of the major B cell subpopulations (B-1, follicular B, marginal zone B, and regulatory B cells) involved in transplantation rejection are discussed together with their interaction with T cells.

Impact and Modulations of Peripheral and Edaphic B Cell Subpopulations in Chronic Rhinosinusitis With Nasal Polyposis

OBJECTIVES: The pathophysiological mechanisms of chronic rhinosinusitis with nasal polyposis (CRSwNP) still are discussed controversially. Regulatory B cells (Breg) are responsible for the suppression of T cell activity: deficiencies for Breg have been demonstrated to contribute to autoimmune disorders, e.g., systemic lupus erythematosus. In order to evaluate the influence of B cell subpopulations, especially Breg, on the etiology of this disease, the aim of this study was to characterize subpopulations of peripheral and edaphic B cells in CRSwNP. METHODS: Polypoid tissue and blood samples were collected from 10 patients undergoing paranasal sinus surgery and lymphocytes were analyzed by multicolor flow cytometry. RESULTS: There was a significantly lower frequency of B cells in nasal polyps compared to peripheral blood mononuclear cells (PBMC) in patients with CRSwNP. Mature resting B cells were the main population within B cells in PBMC, and memory B cells in nasal polyps. Remarkably, Breg and mature B cells significantly decreased in nasal polyps compared to PBMC. Memory B cells significantly increased and represented the main subpopulation in nasal polyps in patients with CRSwNP. CONCLUSION: In this study a detailed contemporary characterization of B cell subpopulations in patients with CRSwNP is presented. The influence of edaphic B cells could play a key role in the maintenance of this chronic infectious disease.

Increased receptor activator of nuclear factor kappa B ligand expressed on B10 cells in rheumatoid arthritis / 北京大学学报(医学版)

OBJECTIVE@#To detect receptor activator of nuclear factor kappa B ligand (RANKL) expressed on B10 cells in rheumatoid arthritis (RA) and to evaluate the correlation between RANKL-producing B10 cells in RA and clinical features and laboratory parameters, trying to reveal the possible role of B10 cells in the pathogenesis of RA and the potential mechanism of impaired immunosuppressive capacities.@*METHODS@#25 RA patients and 20 healthy volunteers were enrolled. These RA patients did not received treatment with glucocorticoids, disease-modifying anti-rheumatic drug and biologics during the recent half of a year. The levels of RANKL-producing B10 cells were measured by flow cytometry (FCM) and polymerase chain reaction (PCR). The correlation between the frequencies of RANKL-producing B10 cells in RA and clinical data, laboratory parameters were analyzed. The role of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in inducing RANKL expression in B10 cells was evaluated by in vitro stimulation assay. Independent samples t test, Pearson and Spearman correlation were used for statistical analysis.@*RESULTS@#B10 cells were capable of producing RANKL at a low level in health controls. The frequencies of RANKL-producing B10 cells were markedly higher in RA patients than in health controls (3.65%±1.59% vs. 2.25%±0.68%, P<0.01). The frequencies of these cells correlated positively with RA tender joint counts, swollen joint counts and disease activity score in 28 joints (DAS28) (r=0.479, P=0.035; r=0.519, P=0.008; r=0.526, P=0.019). However, no correlation was found between these cells and RA patient age, disease duration, or the levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF) and anti-citrullinated peptide antibody (ACPA). After in vitro stimulation by TNF-α, but not IL-1β, B10 cells isolated from healthy donors demonstrated fundamentally upregulated expression of RANKL.@*CONCLUSION@#Our studies showed the frequencies of RANKL-producing B10 cells were markedly higher in RA patients, and their frequencies were positively correlated with RA tender joint counts, swollen joint counts and DAS28. These findings suggested that B10 cells might be involved in RA bone destruction.

Toll-like receptor agonists Porphyromonas gingivalis LPS and CpG differentially regulate IL-10 competency and frequencies of mouse B10 cells

Abstract IL-10 expressing regulatory B cells (B10) play a key role in immune system balance by limiting excessive inflammatory responses. Effects of toll-like receptor signaling and co-stimulatory molecules on B10 activity during innate and adaptive immune responses are not fully understood. Objective This study is to determine the effects of P. gingivalis LPS and CpG on B10 cell expansion and IL-10 competency in vitro. Material and Methods Spleen B cells were isolated from C57BL/6J mice with or without formalin-fixed P. gingivalis immunization. B cells were cultured for 48 hours under the following conditions: CD40L, CD40L+LPS, CD40L+CpG, and CD40L+LPS+CpG in the presence or absence of fixed P. gingivalis. Percentages of CD1dhiCD5+ B cells were measured by flow cytometry. IL-10 mRNA expression and secreted IL-10 were measured by real-time quantitative PCR and by ELISA respectively. Results P. gingivalis LPS plus CD40L significantly increased CD1dhiCD5+ B cell percentages and secreted IL-10 levels in both immunized and non-immunized mice B cells in the presence or absence of P. gingivalis, compared with control group. Secreted IL-10 levels were significantly increased in CD40L+LPS treated group compared with CD40L treatment group in the absence of P. gingivalis. CpG plus CD40L significantly decreased CD1dhiCD5+ B cell percentages, but greatly elevated secreted IL-10 levels in immunized and non-immunized mice B cells in the absence of P. gingivalis, compared with CD40L treatment group. Conclusions P. gingivalis LPS and CpG differentially enhance IL-10 secretion and expansion of mouse B10 cells during innate and adaptive immune responses.

Unusual Suspects in the Development of Obesity-Induced Inflammation and Insulin Resistance: NK cells, iNKT cells, and ILCs

The notion that obesity-induced inflammation mediates the development of insulin resistance in animal models and humans has been gaining strong support. It has also been shown that immune cells in local tissues, in particular in visceral adipose tissue, play a major role in the regulation of obesity-induced inflammation. Specifically, obesity increases the numbers and activation of proinflammatory immune cells, including M1 macrophages, neutrophils, Th1 CD4 T cells, and CD8 T cells, while simultaneously suppressing anti-inflammatory cells such as M2 macrophages, CD4 regulatory T cells, regulatory B cells, and eosinophils. Recently, however, new cell types have been shown to participate in the development of obesity-induced inflammation and insulin resistance. Some of these cell types also appear to regulate obesity. These cells are natural killer (NK) cells and innate lymphoid cells (ILCs), which are closely related, and invariant natural killer T (iNKT) cells. It should be noted that, although iNKT cells resemble NK cells in name, they are actually a completely different cell type in terms of their development and functions in immunity and metabolism. In this review, we will focus on the roles that these relatively new players in the metabolism field play in obesity-induced insulin resistance and the regulation of obesity.

Rituximab and Dexamethasone Combined with Cyclophosphamide for Treatment of Relapsed and Refractory Immune Thrombocytopenia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To evaluate the efficiency and safety of rituximab and dexamethasone combined with cyclophosphamide for treating patients with relapsed and refractory immune thrombocytopenia (ITP).</p><p><b>METHODS</b>Twelve patients with relapsed and refractory immune thrombocytopenia were prospectively enrolled in this study, and received rituximab 375 mg/m(2) once a week for 4 weeks, dexamethasone 40 mg once a day for consecutive 4 days, and cyclophosphamide 500 mg/m(2) biweekly for 2 weeks. The levels of IFN-r and IL-4 in peripheral blood of patients were measured by enzyme-linked immunosorbent assay (ELISA), and the percentages of Breg, Treg and Th17 cells were detected by flow cytometry before and after treatment. Efficiency was evaluated according to platelet counts, and side effects were observed.</p><p><b>RESULTS</b>Six out of 12 patients reached to complete remission and 4 patients reached to partial remission, with the total response rate 83.33%. The platelet counts [(115.42 ± 76.60) × 10(9)/L] after treatment were significantly higher than that before treatment [(115.42 ± 76.60) × 10(9)/L] (P < 0.001). The ratio of IFN-r/ IL4 after treatment (5.89 ± 2.30) was very significantly lower than that before treatment (7.00 ± 2.73) (P = 0.002). The percentage of Breg cells after treatment [(21.27 ± 4.28)%] were much significantly higher than that before treatment [(15.48 ± 1.67)%] (P < 0.001). The ratio of Treg/Th17 after treatment (3.07 ± 1.50) was significantly higher than that before treatment (0.98 ± 0.45) (P < 0.001). Infusion reaction was observed in 1 patient, secondary hypertension and hyperglycemia were in 1 patient, and pneumonia in 2 patients.</p><p><b>CONCLUSION</b>Rituximab and dexamethasone combined with cyclophosphamide can improve the outcomes of patients with relapsed and refractory immune thrombocytopenia patients and they were well tolerated, its mechanism may be related with the balance between T cell sunsets and Treg cells.</p>

Avaliação da frequência de linfócitos B reguladores produtores de IL-10 (B10) em pacientes com Imunodeficiência Comum Variável (ICV) / Evaluation of IL-10-producing regulatory B cells in patients with Common Variable Immunodeficiency (CVID)

A Imunodeficiência Comum Variável (ICV) é a imunodeficiência primária sintomática mais comum em adultos. Pacientes ICV frequentemente apresentam diversas alterações de linfócitos B, número reduzido de células Treg e ativação imune crônica, bem como infecções recorrentes, alta incidência de doenças autoimunes e um risco aumentado de doenças malignas. Testamos a hipótese de que a frequência de células B10 estaria diminuída nos pacientes ICV, já que elas desempenham um importante papel no desenvolvimento de células Treg, no controle da ativação de células T e na autoimunidade. Para tanto, nós avaliamos a frequência de células B10 em pacientes ICV buscando correlacioná-la com as diferentes manifestações clínicas e imunológicas associadas à doença. Quarenta e dois (42) pacientes com diagnóstico de ICV e 17 indivíduos saudáveis foram convidados a participar do estudo. A partir das CMSP criopreservadas foram realizados testes de perfil de ativação celular, presença de células T reguladoras (Treg) e caracterização das células B10. Os níveis de sCD14 no plasma foram determinados por ELISA. A produção de IL-10 foi determinada por ELISA em sobrenadante de cultura de células B. Pacientes ICV apresentam frequência diminuída de células B CD24hiCD38hi produtoras de IL-10 em diferentes condições de cultura celular e frequência diminuída de células B CD24hiCD27+ em cultura celular estimulada por CpG+PIB. No entanto, a produção de IL-10 por células B não demonstrou diferença significativa entre pacientes ICV e controles. A frequência de células B10 não teve correlação com a presença de autoimunidade, ativação celular ou frequência de células Treg em pacientes ICV. Este trabalho sugere que pacientes ICV têm um comprometimento na subpopulação de células B reguladoras, mas que não está correlacionado com as características clínicas e imunológicas apresentadas por esses indivíduos.

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency in adults. CVID patients often present changes in the frequency and function of B lymphocytes, reduced number of Treg cells, chronic immune activation, recurrent infections, high incidence of autoimmunity and increased risk for malignancies. We hypothesized that the frequency of B10 cells would be diminished in CVID patients because these cells play an important role in the development of Treg cells and in the control of T cell activation and autoimmunity. Therefore, we evaluated the frequency of B10 cells in CVID patients and correlated it with the different clinical and immunological characteristics of this disease. Forty-two CVID patients and 17 healthy controls were recruited for this study. Cryopreserved PBMCs were used for analysis of T cell activation, frequency of Treg cells and characterization of B10 cells by flow cytometry. Plasma sCD14 levels were determined by ELISA. IL-10 production was determined in supernatant by ELISA after culture of B cells. We found that CVID patients presented a decreased frequency of IL-10-producing CD24hiCD38hi B cells in different cell culture conditions and decreased frequency of IL-10-producing CD24hiCD27+ B cells stimulated with CpG+PIB. However, the B cells secretion of IL-10 was similar between CVID patients and healthy controls. The frequency of B10 cells had no correlation with autoimmunity, immune activation and Treg cells in CVID patients. This work suggests that CVID patients have a compromised regulatory B cell compartment which is not correlated with clinical and immunological characteristics presented by these individuals.

Toxoplasma gondii Infection Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice

PURPOSE: Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects humans and animals via congenital or postnatal routes, and it is found worldwide. Modulation of the immune system by parasite infection is proposed to suppress allergic inflammation. Growing evidences have shown that interleukin (IL)-10-producing regulatory B cells (B(regs)) and CD4+CD25+FoxP3+ regulatory T cells (T(regs)) induced by parasite infection play a critical role in allergic or autoimmune diseases because these cells regulate negatively cellular immune responses and inflammation. Currently, the role of IL-10-producing regulatory B cells in host immune response during T. gondii infection is unknown. In this study, we investigate whether T. gondii infection can suppress the development of unrelated atopic dermatitis (AD)-like lesions. METHODS: AD is a chronically relapsing inflammatory skin disease accompanied by severe itching; for this, we used NC/Nga mice, a well-known experimental model of systemic AD. Repeated exposure to Dermatophagoides farinae crude extract (DfE), known as a major environmental allergen, evokes AD-like skin lesions in NC/Nga mice under specific pathogen-free conditions. NC/Nga mice were intraperitoneally infected with 10 cysts of T. gondii. RESULTS: T. gondii infection significantly ameliorated AD-like skin lesions in NC/Nga mice. The subpopulation of B(regs) and T(regs) in the AD mice was expanded in the course of T. gondii infection. In addition, T. gondii infection inhibited Th2 and enhanced Th1 immune response in the DfE-treated AD mice. CONCLUSIONS: We have experimentally demonstrated for the first time that T. gondii infection ameliorated AD-like skin lesions in a mouse model of AD. Our study could in part explain the mechanisms of how parasite infection prevents the development of allergic disorder. Therefore, these immunemechanisms induced by T. gondii infection may be beneficial for the host in terms of reduced risk of allergic immune reactions.

Regulatory B cells present in lymph nodes draining a murine tumor

In cancer, B cells have been classically associated with antibody secretion, antigen presentation and T cell activation. However, a possible role for B lymphocytes in impairing antitumor response and collaborating with tumor growth has been brought into focus. Recent reports have described the capacity of B cells to negatively affect immune responses in autoimmune diseases. The highly immunogenic mouse tumor MCC loses its immunogenicity and induces systemic immune suppression and tolerance as it grows. We have previously demonstrated that MCC growth induces a distinct and progressive increase in B cell number and proportion in the tumor draining lymph nodes (TDLN), as well as a less prominent increase in T regulatory cells. The aim of this research was to study B cell characteristics and function in the lymph node draining MCC tumor and to analyze whether these cells may be playing a role in suppressing antitumor response and favoring tumor progression. Results indicate that B cells from TDLN expressed increased CD86 and MHCII co-stimulatory molecules indicating activated phenotype, as well as intracellular IL-10, FASL and Granzyme B, molecules with regulatory immunosuppressive properties. Additionally, B cells showed high inhibitory upon T cell proliferation ex vivo, and a mild capacity to secrete antibodies. Our conclusion is that even when evidence of B cell-mediated activity of the immune response is present, B cells from TDLN exhibit regulatory phenotype and inhibitory activity, probably contributing to the state of immunological tolerance characteristic of the advanced tumor condition.

Significance of regulatory B cells in nosogenesis of immune thrombocytopenia / 中国实验血液学杂志

This study was aimed to investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia (ITP) and its clinical significance. A total of 35 ITP patients and 20 normal controls were enrolled in this study. The expression of CD19(+)CD24(hi)CD38(hi) B cells was detected by flow cytometry and the expression of IL-10 mRNA and TGF-β1 mRNA was assayed by RT-PCR. The results indicated that the expression level of CD19(+)CD24(hi)CD38(hi) B cells in peripheral blood of newly diagnosed ITP patients was obviously lower than that in normal controls (P < 0.05); the expression level of CD19(+)CD24(hi)CD38(hi) B cells in ITP patients with increased platelet count after treatment was higher than that before treatment (P < 0.05); the expression level of IL-10 mRNA in newly diagnosed ITP patients was significantly lower than that the in normal controls (P < 0.05), the expression level of TGF-β1 mRNA in newly diagnosed ITP patients increases as compared with normal controls (P < 0.05), after treatment with DXM the expression of IL-10 mRNA was enhanced, the expression of TGF-β1 mRNA was reduced as compared with expression level before treatment (P < 0.05). It is concluded that the Breg cells may play an important role in the pathogenesis of ITP via humoral immunity and its regulation of T lymphocytes.

Regulatory B Cells Are Inversely Associated with Disease Activity in Rheumatoid Arthritis

PURPOSE: The function of regulatory B lymphocytes is known to be abnormal in inflammatory diseases. However, a recent study indicates that IL-10+ B cells seem to be expanded in rheumatoid arthritis (RA). Therefore, the state of IL-10+ B cells in the peripheral blood from RA patients and healthy controls were investigated. MATERIALS AND METHODS: CD19+ cells in peripheral blood mononuclear cells were purified from blood samples of RA patients and age and gender-matched healthy controls, and stimulated with CD40 ligand and CpG for 48 hours. Then, intracellular IL-10 in CD19+ cells was analyzed using flow cytometry. RESULTS: There was no significant difference in the proportion of IL-10+ B cells between 10 RA patients and 10 healthy controls (RA, 0.300+/-0.07 vs. healthy control 0.459+/-0.07, p=0.114). The proportion of induced IL-10+ B cells to total B cells in RA patients was significantly higher than those in controls (RA, 4.44+/-3.44% vs. healthy control 2.44+/-1.64%, p=0.033). However, the proportion of IL-10+ B cells to total B cells correlated negatively with disease activity in RA patients (r=-0.398, p=0.040). Erythrocyte sedimentation rate or C-reactive protein or medication was not associated with the proportion of IL-10+ B cells. CONCLUSION: The proportion of induced IL-10+ B cell increased in RA patients compared to healthy control, however, negatively correlated with disease activity in RA.

BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs) play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF) is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment.

Correlation of Breg with CD4(+)T cells of peripheral blood in patients with CITP and its clinical significance / 中国实验血液学杂志

This study was aimed to detect the level of the peripheral blood Breg and CD4(+) T cell subgroups in patients with chronic idiopathic thrombocytopenic purpura (CITP) before and after therapy, and to analyse the charge of related cytokines and their correlation, to explore their roles in the pathogenesis of CITP. A total of 35 CITP cases were taken as the research group and 35 healthy persons were served as the control group. The peripheral blood mononuclear cells (PBMNC) were separated, the percentages of Th1, Th17, Th22 and Breg cells were detected by flow cytometry before and after treatment of glucocorticoid, and the IFN-γ, IL-17, IL-22 and IL-10 levels from PBMNC culture supernatant also were determined by ELISA. The results showed that there was significant difference as compared with the healthy controls, the proportion of peripheral blood Th1, Th17, Th22 cell subgroups all increased in CITP patients before treatment with glucocorticoid, the regulatory B cells (Breg) ratio was reduced, the differences had statistical significance (P < 0.05), but the differences were no statistically significant after treatment with glucocorticoid (P > 0.05). The levels of IFN-γ, IL-17, IL-22 from culture supernatant all increased in CITP patients before treatment, the level of IL-10 was lower than that of the healthy control, the difference was statistically significant (P < 0.05), but the there were no statistically significant differences after treatment (P > 0.05). There were positive correlation between the Breg cells and IL-10 expression in CITP patients (P < 0.05), the Breg cells and Th1, Th17, Th22 cells showed a negative correlation, IL-10 and IFN-γ, IL-17, IL-22 levels also showed a negative correlation. It is concluded that the down-regulation of regulatory B cells proportion and the IL-10 level may participate in the mechanism of CD4(+) T cell immunity disorder in CITP, which can provide new targets and ideas for the clinical immune regulation therapy.

In Vitro Induction of Allergen-Specific Interleukin-10-Producing Regulatory B Cell Responses by Interferon-gamma in Non-Immunoglobulin E-Mediated Milk Allergy

PURPOSE: Specific oral immunotherapy (SOIT) using interferon-gamma (IFN-gamma) has been successful as a food allergy treatment. Interleukin-10 (IL-10)-producing regulatory B cells (Br1s) play a role in immune tolerance to food allergens. In addition, IFN-gamma shows tolerogenic effects on allergen-induced Br1 responses. METHODS: Eleven patients that were allergic to cow's milk and 12 milk-tolerant subjects were selected by double-blind placebo-controlled food challenge (DBPCFC) and clinical characteristics. The immunomodulatory effects of IFN-gamma on allergen-specific Br1 responses were evaluated in 6 milk allergy patients and 8 milk-tolerant subjects. Peripheral blood mononuclear cells (PBMCs) from subjects were stimulated with casein and/or IFN-gamma and analyzed by flow cytometry. RESULTS: IFN-gamma had no effect on total cell counts or the proportion of Br1 cells in PBMCs. IFN-gamma stimulation did not change total Br1 cell counts or the percentage of Br1s among CD5(+) B cells in the milk allergy or the milk-tolerant groups. In the milk allergy group, Br1 counts were not different between the control and the casein stimulation but significantly increased in the IFN-gamma + casein stimulated cells, and the Br1 fractions were decreased after casein stimulation and recovered in the addition of IFN-gamma for stimulation. In the milk-tolerant group, Br1 counts increased in the casein stimulated cells and in the IFN-gamma + casein stimulated cells, but the increase was significantly less when IFN-gamma was added, and the Br1 fractions were increased after casein stimulation and IFN-gamma + casein stimulation, that was not significant when IFN-gamma was added. CONCLUSIONS: IFN-gamma-induced allergen-specific Br1 responses in the PBMCs of milk allergy patients play a role in milk allergen-specific tolerance induction in vitro. Further investigations into the molecular immunological mechanisms underlying the induction of allergen-specific Br1 responses are needed.