Characterisation of allergen-specific responses of IL-10-producing regulatory B cells (Br1) in Cow Milk Allergy

CD19+CD5+ regulatory B cells regulate immune responses by producing IL-10. IL-10-producing regulatory B cell (Br1) responses by allergen stimulation were investigated in human food allergy. Six milk allergy patients and eight milk-tolerant subjects were selected according to DBPCFC. PBMCs were stimulated by casein in vitro and stained for intracellular IL-10 and apoptosis. In response to allergen stimulation, Br1 decreased from 26.2 ± 18.3 to 15.5 ± 8.9% (p = 0.031, n = 6) in the milk allergy group and increased from 15.4 ± 9.0 to 23.7 ± 11.2% (p = 0.023, n = 8) in the milk-tolerant group. Apoptotic non-IL-10-producing regulatory B cells increased from 21.8 ± 9.3 to 38.0 ± 16.1% (p = 0.031, n = 6) in the milk allergy group and unchanged from 28.8 ± 13.8 to 28.0 ± 15.0% (p = 0.844, n = 8) in the milk-tolerant group. Br1 may be involved in the immune tolerance of food allergies by producing IL-10 and simultaneously undergoing apoptosis in humans. The exact roles for Br1 in immune tolerance needs to be further investigated.     

IL-10-producing regulatory B cells (B10 cells) in autoimmune disease

B cell abnormalities contribute to the development and progress of autoimmune disease.Traditionally, the role of B cells in autoimmune disease was thought to be predominantly limited tothe production of autoantibodies. Nevertheless, in addition to autoantibody production, B cells haveother functions potentially relevant to autoimmunity. Such functions include antigen presentation toand activation of T cells, expression of co-stimulatory molecules and cytokine production. Recently,the ability of B cells to negatively regulate cellular immune responses and inflammation has beendescribed and the concept of regulatory B cells has emerged. A variety of cytokines produced byregulatory B cell subsets have been reported, with IL-10 being the most studied. In this review,this specific IL-10-producing subset of regulatory B cells has been labeled B10 cells to highlightthat the regulatory function of these rare B cells is mediated by IL-10, and to distinguish themfrom other B cell subsets that regulate immune responses through different mechanisms. B10 cells area functionally defined subset currently identified only by their competency to produce and secreteIL-10 following appropriate stimulation. Although B10 cells share surface markers with otherpreviously defined B cell subsets, currently there is no cell surface or intracellular phenotypicmarker or set of markers unique to B10 cells. The recent discovery of an effective way to expand B10cells ex vivo opens new horizons in the potential therapeutic applications of this rare Bcell subset. This review highlights the current knowledge on B10 cells and discusses their potentialas novel therapeutic agents in autoimmunity.     

Properties of interleukin-1 and interferon-gamma receptors in B lymphoid cell line

We have previously shown that interleukin-1 alpha (IL-1 alpha) and interferon-gamma (IFN-gamma) induce surface IgM expression, stimulate Na+/H+ exchange, and activate protein kinase C in the murine pre-B lymphocyte cell line, 70Z/3. Because the two structurally different lymphokines induce similar effects, in this study we set out to compare the properties of the IL-1 and IFN-gamma surface receptors. In contrast to their similar cellular effects, we found that IL-1 alpha and IFN-gamma receptors have different properties. 70Z/3 have high (100 sites/cell) and low (900 sites/cell) affinity IL-1 receptors with dissociation constants (KD) 6 x 10(-11) and 10(-9) M, respectively. In contrast, IFN-gamma receptors are of one class with a KD of 3 x 10(-10) M and are at a higher number, 8000 sites/cell. After binding to their receptors both IL-1 alpha and IFN-gamma are internalized and intracellularly degraded, but the rate of internalization of IFN-gamma is greater than IL-1 alpha. The effective median concentrations (EC50) of IL-1 alpha- or IFN-gamma-induced surface IgM expression are similar (4-5 x 10(-12) M). However, at this concentration 10-fold more of IFN-gamma than IL-1 alpha molecules are bound per cell. Our studies indicate that structurally different lymphokines can induce similar biological events even though their signaling is mediated by surface receptors whose properties are different.     

Potential role of interleukin-10-secreting regulatory T cells in allergy and asthma

Allergic diseases are caused by aberrant T-helper-2 immune responses in susceptible individuals. Both naturally occurring CD4(+)CD25(+) regulatory T cells and inducible populations of antigen-specific interleukin-10-secreting regulatory T cells inhibit these inappropriate immune responses in experimental models. This article discusses the evidence that regulatory T-cell function might be impaired in allergic and asthmatic disease and that certain therapeutic regimens might function, at least in part, to promote regulatory T-cell generation. Current research strategies seek to exploit these observations to improve the generation of allergen-specific regulatory T-cell populations with the potential to provide the safe and long-term alleviation of disease symptoms.     

In vitro effects of genistein and resveratrol on the production of interferon-gamma (IFNgamma) and interleukin-10 (IL-10) by stimulated murine splenocytes.

Phytoestrogens are a group of plant-derived biologically active substances with a chemical structure that resembles that of 17beta-estradiol (E2). As the presence of estrogen receptors (ER) has been identified in several immune cells, phytoestrogens may also have a great impact on the immune system. The aim of our study was to determine the in vitro effects of genistein and resveratrol on the production of interferon-gamma (IFNgamma) and interleukin-10 (IL-10) by stimulated murine splenocytes and compare them with the effects of natural E2. Phorbol 12-miristate 13-acetate (PMA) together with ionomycin was used to stimulate the cells. E2 and genistein did not show any significant effects on the stimulated production of IFNgamma. Resveratrol had a mild inhibitory effect on IFNgamma production at the concentration of 10(-7)M; however, this difference did not reach statistical significance (p>0.05). IL-10 levels in the splenocytes culture supernatants were found to be increased in the presence of E2, genistein and resveratrol; however, these effects were also not statistically significant. To determine whether the exposure to our studied phytoestrogens induced a shift in the T-helper 1/T-helper 2 (Th1/Th2) balance, we calculated the ratio between the production of IFNgamma, the prototypic Th1 cytokine, and the production of IL-10, the prototypic Th2 cytokine, at different concentrations of our tested substances. Genistein at the concentrations of 10(-6) and 10(-7)M and resveratrol at the concentrations of 10(-6)M decreased significantly the IFNgamma/IL-10 ratio. This decrease was comparable to that of E2 at the concentrations of 10(-7)M. From our in vitro experiments we conclude that genistein and resveratrol, similarly to E2, by decreasing the IFNgamma/IL10 ratio may shift the Th1/Th2 balance towards the Th2 response.     

The combination of the interleukin-1alpha (IL-1alpha-889) genotype and the interleukin-10 (IL-10 ATA) haplotype is associated with increased interleukin-10 (IL-10) plasma levels in healthy individuals

Family studies have demonstrated striking differences between individuals in their ability to produce IL-10 following lipopolysaccharide (LPS) stimulation of whole blood cultures in vitro, suggesting that differences in IL-10 production involve a considerable hereditary component. The first aim of this study was to analyse the possible effect of IL-10 genotypes and haplotypes on IL-10 plasma levels in a healthy Finnish population. As previous reports have demonstrated that endogenously produced IL-1 induces LPS-stimulated IL-10 production and that IL-10 inhibits synthesis of IL-1 in human monocytes, it is apparent that these two cytokines form an autoregulatory feedback loop. Secondly, we were interested whether any relationship could be found between IL-10 and IL-1beta in vivo. To examine this, the influence of IL-1alpha -889, IL-1beta -511 and IL-1Ra VNTR genotypes and IL-10 genotypes/haplotypes (ACC, GCC and ATA) on IL-10 plasma levels, and a putative correlation between IL-10 and IL-1alpha plasma levels were analysed. Four hundred adult blood samples were obtained from the Finnish Red Cross Blood Transfusion Centre, Tampere. The IL-10, IL-1alpha, IL-1beta and IL-1Ra gene polymorphisms were analysed using PCR. IL-1beta and IL-10 plasma levels were measured using an ELISA method. Our results indicated that increased IL-10 plasma levels were associated with the ATA haplotype (p = 0.03) and, surprisingly, with the IL-1alpha allele 2 carrier status (p = 0.02) in healthy individuals. This IL-1alpha 2+/ATA+ combination was found in 93 subjects out of 400 analysed (23%) and was associated with significantly high IL-10 plasma levels (p = 0.002). When individuals were classified into three groups, with no detectable IL-10 plasma levels (n = 145), with moderate levels (n = 152) and with high levels (n = 100) of IL-10, the IL-1alpha2+/ATA+ combination was more likely present among those with high levels than among those with undetectable levels of IL-10 (OR = 3.3, 95% CI 1.8 - 6.0, p < 0.001) or those with moderate levels of IL-10 (OR = 2.0, 95% CI 1.2 - 3.6, p = 0.012). Besides the observed association between IL-1alpha genotype and IL-10 levels, a moderate correlation was found between IL-10 and IL-1beta levels (r = 0.6, p = 0.01) among IL-10 producers (n = 252). The present findings suggest that the genotype combination of IL-1alpha 2+/ATA+ has a regulatory effect on basal IL-10 levels and that among individuals with measurable IL-10 plasma levels, IL-1beta and IL-10 basal levels correlate. Until now, data on the feedback loop between IL-1 and IL-10 cytokines have been based on studies in vitro, but now our results suggest that this relationship may also exist in vivo.     

Interleukin-10 (IL-10) inhibits the induction of nitric oxide synthase by interferon-gamma in murine macrophages.

A murine macrophage cell line, J774, expresses high levels of the enzyme nitric oxide synthase (NOS) and produces large amounts of nitric oxide (NO) when activated with recombinant interferon (IFN)-gamma and a low concentration of LPS (10 ng/ml). Both the expression of NOS and the production of NO were inhibited by recombinant IL-10 in a dose-dependent manner. The inhibition was effective only when the cells were pretreated with IL-10; addition of IL-10 at the same time or after IFN-gamma activation was without effect. These results demonstrate that IL-10, a product of Th2 (helper T lymphocyte 2) cells, can antagonise the function of IFN-gamma, a product of Th1 cells, by modulating the mechanism of synthesis of nitric oxide in the macrophages.     

Mice lacking endogenous IL-10-producing regulatory B cells develop exacerbated disease and present with an increased frequency of Th1/Th17 but a decrease in regulatory T cells

IL-10-producing B cells, also known as regulatory B cells (Bregs), play a key role in controlling autoimmunity. In this study, we report that chimeric mice specifically lacking IL-10-producing B cells (IL-10(-/-)B cell) developed an exacerbated arthritis compared with chimeric wild-type (WT) B cell mice. A significant decrease in the absolute numbers of Foxp3 regulatory T cells (Tregs), in their expression level of Foxp3, and a marked increase in inflammatory Th1 and Th17 cells were detected in IL-10(-/-) B cell mice compared with WT B cell mice. Reconstitution of arthritic B cell deficient (μMT) mice with different B cell subsets revealed that the ability to modulate Treg frequencies in vivo is exclusively restricted to transitional 2 marginal zone precursor Bregs. Moreover, transfer of WT transitional 2 marginal zone precursor Bregs to arthritic IL-10(-/-) mice increased Foxp3(+) Tregs and reduced Th1 and Th17 cell frequencies to levels measured in arthritic WT mice and inhibited inflammation. In vitro, IL-10(+/+) B cells established longer contact times with arthritogenic CD4(+)CD25(-) T cells compared with IL-10(-/-) B cells in response to Ag stimulation, and using the same culture conditions, we observed upregulation of Foxp3 on CD4(+) T cells. Thus, IL-10-producing B cells restrain inflammation by promoting differentiation of immunoregulatory over proinflammatory T cells.     

Association of interleukin-1B (IL-1B) gene polymorphisms with risk of gastric cancer in Chinese population

The incidence of gastric cancer (GC) in China is among the highest in the world. In present work, 154 patients with GC and 166 healthy controls in population of north-western China were investigated to evaluate the genetic associations of IL-1B gene single nucleotide polymorphisms (SNP) and variable number tandem repeat (VNTR) polymorphisms of IL-1RN gene with increased risk of GC. The frequency of IL-1B+3954C/T was significantly higher in GC cases group (25.97%) than that in controls (4.82%) with odds ratio (OR)=6.93 (95% confidence interval [CI] 3.13-15.36); the frequencies of IL-1B-31C/T, IL-1B-31C/C and IL-1B-511C/T genotypes were also higher in GC cases group (51.95%, 23.38% and 50.65%) than those in controls (46.99%, 19.88% and 42.77%) with OR=1.48 (95% CI 0.88-2.49), OR=1.58 (95% CI 0.84-2.95) and OR=1.39 (95% CI 0.80-2.41), respectively. The results show that these SNPs of IL-1B gene are associated with significantly increased risk of GC. This is the first report that IL-1B+3954C/T heterozygote is associated with greatly increased risk of GC. The results of this study did not support the report that IL-1RN*2+ genotypes were associated with increased risk of GC in Chinese population.     

Synergistic induction of hepatocyte growth factor in human skin fibroblasts by the inflammatory cytokines interleukin-1 and interferon-gamma

Hepatocyte growth factor (HGF) is one of the vital factors for wound healing. HGF expression markedly increases in wounded skin and is mainly localized in dermal fibroblasts. HGF expression level in human dermal fibroblasts in vitro, however, is low and thus may be stimulated by some factors in the process of wound healing. Candidates of the factors are inflammatory cytokines released by polymorphonuclear and mononuclear cells infiltrating the wounded area, but HGF production in human dermal fibroblasts is only slightly induced by interleukin (IL)-1, tumor necrosis factor (TNF)-alpha or interferon (IFN)-gamma. We here report that a combination of IL-1beta and IFN-gamma or a combination of TNF-alpha and IFN-gamma very markedly induced HGF production. The synergistic effect of the former was more marked than that of the latter. Synergistic effects of IL-1beta and IFN-gamma were observed at more than 10 pg/ml and 10 IU/ml, respectively, and were detectable as early as 12 h after addition. Neither IFN-alpha nor IFN-beta was able to replace IFN-gamma. HGF mRNA expression was also synergistically upregulated by IL-1beta and IFN-gamma. IL-1beta plus IFN-gamma-induced synergistic production of HGF was potently inhibited by treatment of cells with the extracellular signal-regulated kinase (ERK) kinase inhibitor PD98059 and the p38 inhibitor SB203580 but not by the c-Jun N-terminal kinase (JNK) inhibitor SP600125. Taken together, our results indicate that a combination of IL-1beta and IFN-gamma synergistically induced HGF production in human dermal fibroblasts and suggest that activation of ERK and p38 but not of JNK is involved in the synergistic effect.     

Inhibition of hepatocyte growth factor induction in human dermal fibroblasts by interleukin-1 and its prevention by interferon-gamma

Hepatocyte growth factor (HGF) is one of the vital factors for liver regeneration. HGF production is induced by the activation of protein kinase A and protein kinase C-mediated pathways, interleukin (IL)-1, tumor necrosis factor (TNF)-alpha, and epidermal growth factor (EGF) in mesenchymal cells. We here report that IL-1 and TNF-alpha, hitherto regarded as HGF inducers, potently inhibited HGF production stimulated by other HGF inducers. IL-1alpha, IL-1beta, and TNF-alpha alone had minimal stimulating effects on HGF production in human dermal fibroblasts, but they strongly inhibited production of HGF induced by cholera toxin, 8-bromo-cAMP, EGF, and phorbol 12-myristate 13-acetate (PMA). Moreover, although the high level of HGF production in MRC-5 cells was enhanced by PMA and less markedly by IL-1beta, HGF production in MRC-5 cells treated with PMA plus IL-1beta was less than that in the cells treated with PMA alone. In the presence of interferon (IFN)-gamma, however, cholera toxin- and 8-bromo-cAMP-induced HGF production was not inhibited by IL-1beta. Pretreatment of cells with IL-1beta suppressed the phosphorylation of cAMP-responsive element-binding protein induced by cholera toxin but not that induced by 8-bromo-cAMP. Taken together, our results indicate that IL-1 inhibited HGF production stimulated by various inducers, including protein kinase A-activating agents, and that IFN-gamma overcame this inhibition of induction of HGF production.     

Differential effects of iron deficiency and underfeeding on serum levels of interleukin-10, interleukin-12p40, and interferon-gamma in mice

BACKGROUND: Over-production of interferon-gamma (IFN-gamma) and under-production of interleukin-10 (IL-10) are associated with autoimmunity, whereas the opposite is associated with overwhelming infections. The influence of iron deficiency, a public health problem for children on in vivo secretion of these cytokines has not been previously investigated. OBJECTIVE: To determine whether iron deficiency alters serum levels of IFN-gamma, IL-10, and IL-12 in mice. DESIGN AND METHODS: Cytokine levels were measured by enzyme immunoassay in iron-deficient (ID), control (C), pair-fed (PF), and iron replete C57BL/6 mice for 3 (R3) and 14 (R14) days (n = 24-28, 12 R14). RESULTS: Iron deficiency was associated with > or = 50% reduction in hemoglobin, hematocrit, liver iron stores, and thymus weight (p < 0.05). Iron repletion improved these measurements. While iron deficiency significantly reduced IL-12p40 (64%) and IFN-gamma (66%) levels, underfeeding reduced those of IL-10 (48%) (p < 0.05). Iron repletion improved cytokine concentrations to PF levels. Thymus atrophy observed in 16 ID and 19 R3 mice, had no effect on IL-12p40 and IFN-gamma, whereas it further decreased IL-10 levels by 72% (p < 0.05). Cytokine levels positively correlated with indicators of iron status, body and thymus weights (r < or = 0.688, p < 0.05). CONCLUSION: Data suggest that iron deficiency alters the balance between pro- and anti-inflammatory cytokines, a change that may affect innate and cell-mediated immunity, and risk of autoimmune disorders.     

Plasma interferon-gamma, interleukin-10 and soluble markers of immune activation in infants with primary adenovirus (ADV) and respiratory syncytial virus (RSV) infection

Adenovirus (ADV) and respiratory syncytial virus (RSV) are etiological agents of acute respiratory tract infection in infants. Long-term prognosis of ADV infection includes severe lung damage, bronchiectasis and hyperlucent lung, while RSV infection is associated with development of recurrent wheezing and subsequent asthma. These differences may be related to differences in the primary immune responses elicited by these viruses. In this paper, we investigated the type of cytokine responses and the magnitude of immune activation in ADV and RSV infections in infants. We examined plasma concentrations of interferon-gamma (IFN-gamma), interleukin-10 (IL-10), soluble interleukin-2 receptor (sCD25) and soluble tumor necrosis factor receptor II (sTNFR-II) in previously healthy infants during the acute phase of primary ADV infection (n = 21) and RSV infection (n = 68), and in uninfected controls (n = 44). In ADV-infected infants, IFN-gamma plasma levels were significantly higher than those observed in RSV cases and the control group (p < 0.05). RSV cases did not show any differences in IFN-gamma plasma levels compared to the other groups. sCD25 levels were significantly higher in ADV- and RSV-infected infants than in controls (p < 0.0001), and higher in ADV than in RSV cases (p < 0.05). sTNFR-II levels were significantly higher in RSV- and ADV-infected infants than in controls (p < 0.0001, p < 0.05, respectively), and higher in RSV than in ADV infection (p < 0.05). No significant differences were observed in IL-10 plasma concentrations between the three groups. These results indicate that ADV and RSV infections in infants differ significantly with regard to the magnitude of production of interferon-gamma and soluble immune activation markers sCD25 and sTNFR-II. These immunological differences may be involved in the different clinical outcomes associated with these viral infections.     

Thrombospondin-1 (TSP1)-producing B Cells Restore Antigen (Ag)-specific Immune Tolerance in an Allergic Environment

Restoration of the antigen (Ag)-specific immune tolerance in an allergic environment is refractory. B cells are involved in immune regulation. Whether B cells facilitate the generation of Ag-specific immune tolerance in an allergic environment requires further investigation. This paper aims to elucidate the mechanism by which B cells restore the Ag-specific immune tolerance in an allergic environment. In this study, a B cell-deficient mouse model was created by injecting an anti-CD20 antibody. The frequency of tolerogenic dendritic cell (TolDC) was assessed by flow cytometry. The levels of cytokines were determined by enzyme-linked immunosorbent assay. The expression of thrombospondin-1 (TSP1) was assessed by quantitative real-time RT-PCR, Western blotting, and methylation-specific PCR. The results showed that B cells were required in the generation of the TGF-β-producing TolDCs in mice. B cell-derived TSP1 converted the latent TGF-β to the active TGF-β in DCs, which generated TGF-β-producing TolDCs. Exposure to IL-13 inhibited the expression of TSP1 in B cells by enhancing the TSP1 gene DNA methylation. Treating food allergy mice with Ag-specific immunotherapy and IL-13 antagonists restored the generation of TolDCs and enhanced the effect of specific immunotherapy. In conclusion, B cells play a critical role in the restoration of specific immune tolerance in an allergic environment. Blocking IL-13 in an allergic environment facilitated the generation of TolDCs and enhanced the therapeutic effect of immunotherapy.     

Shifting hierarchies of interleukin-10-producing T cell populations in the central nervous system during acute and persistent viral encephalomyelitis

Interleukin-10 (IL-10) mRNA is rapidly upregulated in the central nervous system (CNS) following infection with neurotropic coronavirus and remains elevated during persistent infection. Infection of transgenic IL-10/green fluorescent protein (GFP) reporter mice revealed that CNS-infiltrating T cells were the major source of IL-10, with minimal IL-10 production by macrophages and resident microglia. The proportions of IL-10-producing cells were initially similar in CD8(+) and CD4(+) T cells but diminished rapidly in CD8(+) T cells as the virus was controlled. Overall, the majority of IL-10-producing CD8(+) T cells were specific for the immunodominant major histocompatibility complex (MHC) class I epitope. Unlike CD8(+) T cells, a large proportion of CD4(+) T cells within the CNS retained IL-10 production throughout persistence. Furthermore, elevated frequencies of IL-10-producing CD4(+) T cells in the spinal cord supported preferential maintenance of IL-10 production at the site of viral persistence and tissue damage. IL-10 was produced primarily by the CD25(+) CD4(+) T cell subset during acute infection but prevailed in CD25(-) CD4(+) T cells during the transition to persistent infection and thereafter. Overall, these data demonstrate significant fluidity in the T-cell-mediated IL-10 response during viral encephalitis and persistence. While IL-10 production by CD8(+) T cells was limited primarily to the time of acute effector function, CD4(+) T cells continued to produce IL-10 throughout infection. Moreover, a shift from predominant IL-10 production by CD25(+) CD4(+) T cells to CD25(-) CD4(+) T cells suggests that a transition to nonclassical regulatory T cells precedes and is retained during CNS viral persistence.     

CDC28 protein kinase regulatory subunit 1B (CKS1B) expression and genetic status analysis in oral squamous cell carcinoma

CKS1B is a member of the highly conserved cyclin kinase subunit 1 (CKS1) protein family which interacts with cyclin-dependent kinases and plays a critical role in cell cycle progression. In oral squamous cell carcinoma (OSCC), as in other malignancies, CKS1B overexpression has been correlated with reduced survival. To our knowledge, no studies evaluating the genetic status of CKS1B gene in OSCC have been reported. Herein, genetic and protein status of CKS1B were analyzed by immunohistochemical (IHC) and fluorescence in situ hybridization (FISH) techniques in a series of primary OSCC (n=51) and lymph node OSCC metastases samples (n=14). The observed results were compared with those obtained in either inflammatory (oral lichen planus [OLP]) (n=13) and premalignant oral mucosal lesions (oral leukoplakia) (n=16). A significant CKS1B overexpression was observed in OSCC and lymph node metastases samples than in OLP and oral leukoplakia (mean 70% vs 35%, p<0.001). CKS1B overexpression correlated with p27 loss of expression (p=0.0013) and SKP2 overexpression (p<0.00). FISH study disclosed statistical differences in both gene amplifications and gains between samples corresponding to OSCC and metastases from those of OLP and leukoplakia (p<0.001). Amplifications were present in 53% of OSCC samples and 33% of lymph node metastases vs 14% of oral leukoplakia and 0% of OLP biopsy specimens (p=0.002). Polysomies of chromosome 1 were seen in 46% of OSCC, 33% of ganglionar metastases, 14% of oral leukoplakia and 10% of OLP (p=0.036). Correlation of CKS1B over-expression and gains (both polysomies and amplifications) determined by FISH was statistically significant (p<0.001). Our results indicate that a high CKS1B expression is a common finding in primary OSCC which correlates with p27 low expression and SKP2 overexpression. This phenomenon may be due either to numerical (chromosome 1 polysomy) or structural (amplifications) CKS1B genetic abnormalities. This phenotypical and cytogenetic profile is not observed in premalignant or inflammatory oral mucosal lesions.     

Autocrine stimulation of IL-10 is critical to the enrichment of IL-10-producing CD40hiCD5+ regulatory B cells in vitro and in vivo

IL-10-producing B (Breg) cells regulate various immune responses. However, their phenotype remains unclear. CD40 expression was significantly increased in B cells by LPS, and the Breg cells were also enriched in CD40^hiCD5⁺ B cells. Furthermore, CD40 expression on Breg cells was increased by IL-10, CD40 ligand, and B cell-activating factor, suggesting that CD40^hi is a common phenotype of Breg cells. LPS-induced CD40 expression was largely suppressed by an anti-IL-10 receptor antibody and in IL-10^−/−CD5⁺CD19⁺ B cells. The autocrine effect of IL-10 on the CD40 expression was largely suppressed by an inhibitor of JAK/STAT3. In vivo, the LPS treatment increased the population of CD40^hiCD5⁺ Breg cells in mice. However, the population of CD40^hiCD5⁺ B cells was minimal in IL-10^−/− mice by LPS. Altogether, our findings show that Breg cells are largely enriched in CD40^hiCD5⁺ B cells and the autocrine effect of IL-10 is critical to the formation of CD40^hiCD5⁺ Breg cells. [BMB Reports 2015; 48(1): 54-59]     

Missense mutations of the interleukin-12 receptor beta 1(IL12RB1) and interferon-gamma receptor 1 (IFNGR1) genes are not associated with susceptibility to lepromatous leprosy in Korea

Interleukin-12 receptor beta 1 ( IL12RB1), interleukin-12 receptor beta 2 ( IL12RB2), and interferon gamma receptor 1 ( IFNGR1) perform important roles in the host defense against intracellular pathogens such as Mycobacteria. Several mutations within their genes have been confirmed as associated with increased susceptibility to mycobacterial infection. However, the association between mutations of the IL12RB1, IL12RB2, and IFNGR1 encoding genes and lepromatous leprosy has not been studied. This study screened for polymorphisms within IL12RB1, IL12RB2, and IFNGR1 encoding genes in the Korean populations using polymerase chain reaction (PCR)/single-strand conformation polymorphism (SSCP) DNA sequencing assay, and an association study was performed using the missense mutations of 705 A/G (Q214R), 1196 G/C (G378R), 1637 G/A (A525T), and 1664 C/T (P534S) of the IL12RB1, 83 G/A (V14M), and 1443 T/C (L467P) for the IFNGR1 encoding genes. There were no differences in the genotype and allele frequencies of IL12RB1 and IFNGR1 genes between 93 lepromatous leprosy patients and 94 control subjects. In conclusion, missense mutations of 705 A/G (Q214R), 1196 G/C (G378R), 1637 G/A (A525T), 1664 C/T (P534S) of the IL12RB1, 83 G/A (V14 M), and 1443 T/C (L467P) of the IFNGR1 encoding genes have no association with the susceptibility to lepromatous leprosy in the Korean population.