人干扰素调节因子3基因启动子的初步鉴定

子活性分析表明,IRF3启动子区域定位于主要转录起始位点区域前111-167 bp的区域内.采用转录因子结合位点预测分析软件分析表明,该区域内存在E2F转录因子结合位点.结论 -167～-111 bp区存在IRF3启动子的核心调控元件,转录因子E2F可能参与IRF3的转录调控.     

脂多糖刺激干扰素调节因子3促进小鼠腹腔巨噬细胞白介素-17表达

目的：探讨干扰素调节因子3（IRF3）对脂多糖（LPS）刺激小鼠腹腔巨噬细胞促进白细胞介素-17（IL-17） 表达的初步作用机制。方法：小鼠腹腔注射3%巯基乙酸肉汤,3 d 后提取C57BL/6 野生和IRF3 基因敲除小鼠的 腹腔巨噬细胞,培养过夜后添加LPS。收集细胞培养上清液,酶联免疫吸附试验检测细胞因子IL-17 和白细胞介素-6 （IL-6）的表达;提取细胞蛋白质,免疫印迹检测细胞核因子κB抑制蛋白（IκB）α、IRF3、磷酸化信号转导子和 转录激活子3（STAT3）的蛋白水平。结果：LPS 刺激小鼠腹腔巨噬细胞后,IRF3 可显著地促进IL-17 的产生,同 时伴随着IL-6 的产生、IκBα 蛋白的降解及STAT3 的磷酸化。结论：IRF3 可能通过促进IL-6 的产生,间接地激活 STAT3 的磷酸化,进而促进IL-17 的产生。     

IL-6-mediated intersubgenotypic variation of interferon sensitivity in hepatitis C virus genotype 2a/2b chimeric clones

Mechanisms of difference in interferon sensitivity between hepatitis C virus (HCV) strains have yet to be clarified. Here, we constructed an infectious genotype2b clone and analyzed differences in interferon-alpha sensitivity between HCV-2b and 2a-JFH1 clones using intergenotypic homologous recombination. The HCV-2b/JFH1 chimeric virus able to infect Huh7.5.1 cells and was significantly more sensitive to IFN than JFH1. IFN-induced expression of MxA and 25-OAS was significantly lower in JFH1 than in 2b/JFH1-infected cells. In JFH1-infected cells, expression of SOCS3 and its inducer, IL-6, was significantly higher than in 2b/JFH1-infected cells. The IFN-resistance of JFH1 cells was negated by siRNA-knock down of SOCS3 expression and by pretreatment with anti-IL6 antibody. In conclusion, intergenotypic differences of IFN sensitivity of HCV may be attributable to the sequences of HCV structural proteins and can be determined by SOCS3 and IL-6 expression levels.     

微小RNA-98-5p靶向Kruppel样转录因子9对大鼠心肌缺血/再灌注损伤的保护作用

目的 探讨微小RNA（miR)-98-5p靶向Kruppel样转录因子9(KLF9)对大鼠心肌缺血/再灌注（MI/R）损伤的保护作用。 方法 50只大鼠随机分为假手术组、模型组、miR-98-5p agomir组、agomir-NC组及miR-98-5p agomir+pcDNA-3. 1-KLF9组,每组10只。通过冠状动脉结扎法建立MI/R注模型。HE染色观察心肌组织病理情况;TUNEL检测心肌组织细胞凋亡情况;ELISA检测血清肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)含量;Real-time PCR检测心肌组织miR-98-5p、KLF9 mRNA表达水平;Western blotting检测心肌组织KLF9、Bax和JAK2/STAT3信号通路相关蛋白表达;双荧光素酶报告实验验证miR-98-5p与KLF9的关系。 结果 与假手术组相比,模型组大鼠心肌细胞排列较乱,出现坏死;心肌组织细胞凋亡率、血清CK、CK-MB、LDH含量均升高,心肌组织miR-98-5p表达水平下降,KLF9 mRNA和蛋白及p-JAK2和p-STAT3蛋白表达均升高（P<0.05）。过表达miR-98-5p后,大鼠心肌细胞排列较为整齐,心肌细胞坏死减少;心肌组织细胞凋亡率、血清CK、CK-MB、LDH含量及心肌组织p-JAK2、p-STAT3蛋白表达均下降（P＜0.05）。双荧光素酶报告实验结果验证KLF9是miR-98-5p的靶基因。过表达KLF9逆转了miR-98-5p agomir对心肌损伤大鼠产生的作用。 结论 MiR-98-5p靶向KLF9改善MI/R大鼠心肌损伤,其机制可能与miR-98-5p调控JAK2/STAT3信号通路抑制心肌细胞凋亡相关。     

IL-27 improves migrational and antiviral potential of CB dendritic cells

Interleukin (IL)-27 is known to be increased considerably in cord blood (CB) dendritic cells (DCs) after TLR ligation. Previously, we demonstrated that also basal IL-27 levels are higher in CB DCs. Here, we examined effects of IL-27 on monocyte derived dendritic cells (moDCs) to approach its particular role in the specialized immune system of the human neonate.     

IL-12 inhibits glucocorticoid-induced T cell apoptosis by inducing GMEB1 and activating PI3K/Akt pathway

Interleukin (IL)-12 is an important pro-inflammatory cytokine that has been shown to play a role in T cell survival, at least in part by activating the PI3K/Akt pathway. Glucocorticoid modulatory element binding protein (GMEB)1 and 2 are closely related proteins that modify the glucocorticoid receptor binding locus and thus modulate glucocorticoid-mediated gene induction effects, including apoptosis. GMEB1 associates with caspases and prevents apoptosis of cells in the nervous system. We have observed, in preliminary studies, that IL-12 up-regulates GMEB mRNA in human T cells, and postulated that this may contribute to the anti-apoptotic effect of IL-12 on T cells, in particular with regard to glucocorticoid induced apoptosis. Here, we confirm that IL-12 rescue of dexamethasone induced T cell apoptosis involves the PI3K/Akt pathway and that IL-12 induces GMEB1 and GMEB2. A siRNA knockdown of GMEB1 reverses the protective effect of IL-12 on dexamethasone induced T cell apoptosis. Thus, IL-12 protects T cells from glucocorticoid induced apoptosis via PI3K/Akt pathway and via induction of GMEB1, which is likely to reduce transactivation of the glucocorticoid receptor and induction of apoptotic genes. As glucocorticoid induced apoptosis occurs both in physiological and pathological/therapeutic situations, and IL-12 is actively involved in a variety of inflammatory and immune responses, the ability of IL-12 to inhibit steroid responses and increase T cell survival through GMEB1 has wide ranging implications. Manipulating GMEB may be used therapeutically to enhance the resistance or the sensitivity to steroids.     

Human TH9 differentiation is dependent on signal transducer and activator of transcription (STAT) 3 to restrain STAT1-mediated inhibition

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TLR ligands induce synergistic interferon-β and interferon-λ1 gene expression in human monocyte-derived dendritic cells

Toll-like receptors (TLRs) are pattern-recognition receptors of the innate immune system that recognize various pathogen-associated molecules. TLR ligands are potent activators of immune cells and certain TLR ligands have a synergistic ability to induce the production of pro-inflammatory cytokines. In the present study we have analyzed the potential synergy between TLR3, TLR4 and TLR7/8 ligands in type I and type III interferon (IFN) gene expression in human monocyte-derived dendritic cells (moDCs). We show that stimulation of moDCs with TLR7/8 ligand R848 together with TLR3 or TLR4 ligands, polyI:C or LPS, respectively, leads to a synergistic expression of IFN-β and IFN-λ1 mRNAs. Neutralization of type I IFNs as well as IFN priming prior to stimulation suggest that IFN-dependent positive feedback loop is at least partly responsible for the mechanism of synergy. Enhanced expression of TLR3 and especially TLR7, which are both under the regulation of type I IFNs, correlated to synergistic TLR ligand-dependent induction of IFN-β and IFN-λ1 genes. NF-κB, PI3 kinase and MAP kinase pathways were involved in TLR ligand-induced IFN gene expression as evidenced by pharmacological signaling inhibitors. The data indicates that IFNs contribute to TLR-dependent gene activation in human DCs stimulated with multiple TLR ligands.     

Biallelic interferon regulatory factor 8 mutation: A complex immunodeficiency syndrome with dendritic cell deficiency,monocytopenia, and immune dysregulation

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Making sense of regulatory T cell suppressive function

Several types of regulatory T cells maintain self-tolerance and control excessive immune responses to foreign antigens. The major regulatory T subsets described over the past decade and novel function in transplantation will be covered in this review with a focus on CD4⁺CD25⁺Foxp3⁺ regulatory T (Treg) cells. Multiple mechanisms have been proposed to explain how Treg cells inhibit effector cells but none can completely explain the observed effects in toto. Proposed mechanisms to explain suppressive activity of Treg cells include the generation of inhibitory cytokines, induced death of effector cells by cytokine deprivation or cytolysis, local metabolic perturbation of target cells mediated by changes in extracellular nucleotide/nucleoside fluxes with alterations in intracellular signaling molecules such as cyclic AMP, and finally inhibition of dendritic cell functions. A better understanding of how Treg cells operate at the molecular level could result in novel and safer therapeutic approaches in transplantation and immune-mediated diseases.