Limited IL-12B2 receptor expression during salmonellosis

沙门氏菌病期间 IL-12B2 受体表达有限

• 批准号: 6511235
• 负责人: KENNETH L BOST
• 金额: $ 16.25万
• 依托单位: UNIVERSITY OF NORTH CAROLINA CHARLOTTE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2004-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6511235
• 关键词: Salmonella; Salmonella food poisoning; T lymphocyte; clinical research; cytokine receptors; cytotoxic T lymphocyte; dendritic cells; flow cytometry; helper T lymphocyte; human tissue; interleukin 12; laboratory mouse; macrophage; natural killer cells; polymerase chain reaction; radiotracer; receptor expression; transcription factor; western blottings

DESCRIPTION (provided by applicant): A critical driving force for optimal development of T helper type 1 (TH1) lymphocytes is signaling through the IL-12 receptor. The IL-12 receptor is composed of two subunits, with expression of the IL-12 receptor beta 2 chain (IL-12RB2) dictating a high affinity IL-12 receptor complex. Signaling through this high affinity IL-12 receptor controls the development of TH1 lymphocytes and the maintenance of this phenotype, while limiting lineage commitment to the TH2 phenotype. Since TH1 lymphocytes mediate cellular immunity, while TH2 lymphocytes enhance humoral responses, early expression of the high affinity IL-12 receptor is critical for a commitment to cell mediated immune responses. Salmonella is an intracellular pathogen of macrophages, epithelial cells and possibly dendritic cells, and requires cell-mediated immunity for clearance. Based on recently published work, we demonstrated that Salmonella-infected macrophages can significantly limit IL-12RB2 expression on T lymphocytes early in the response. This finding has profound implications for the early development and commitment of T lymphocytes to the TH1 lineage during Salmonella infection. The overall goal of this proposal is to define the mechanisms for Salmonella-induced reductions in IL-12RB2 expression in vitro and in vivo. At present, it is not clear whether induced reductions in IL-12RB2 expression are solely mediated by soluble factors or require macrophage-T cell contact. IL-12RB2 expression will be quantified at the level of mRNA using quantitative RT-PCR, and at the protein level using Western blot, FACS and radioreceptor analyses. Furthermore, reductions in T lymphocyte function associated with the loss of IL-12RB2 will be assessed, and a functional assessment of developing TH1 and TH2 lymphocytes will be determined by following STAT-4 activation, and T-bet, GATA-3 and c-maf mRNA expression, respectively. Whether infected dendritic cells can induce such alterations in CD4+ T cells will also be determined. Taken together these studies represent the first to define mechanisms whereby an intracellular bacterial pathogen can adversely affect the early development of TH1 lymphocytes upon infection.

描述（由申请人提供）：优化的关键驱动力 辅助性T细胞1型（TH1）淋巴细胞的发育是通过IL-12 受体的IL-12受体由两个亚基组成，表达为 IL-12受体β 2链（IL-12RB2）决定高亲和力IL-12 受体复合物通过这种高亲和力IL-12受体的信号传导控制 TH1淋巴细胞的发育和这种表型的维持，而 限制了TH2表型的谱系定型。由于TH1淋巴细胞介导 细胞免疫，而TH2淋巴细胞增强体液反应，早期 高亲和性IL-12受体的表达对于致力于 细胞介导的免疫反应。沙门氏菌是一种细胞内病原体， 巨噬细胞、上皮细胞和可能的树突细胞，并且需要 细胞介导的免疫清除。根据最近发表的研究，我们 表明沙门氏菌感染的巨噬细胞可以显著限制 应答早期T淋巴细胞上的IL-12RB2表达。这一发现 对T淋巴细胞的早期发育和定型的深远影响 与沙门氏菌感染时的TH1谱系有关。总的目标是 建议是确定沙门氏菌诱导的减少的机制， IL-12RB2在体外和体内的表达。目前尚不清楚是否 诱导的IL-12RB2表达的减少仅由可溶性 因子或需要巨噬细胞-T细胞接触。IL-12RB2的表达将是 使用定量RT-PCR在mRNA水平上定量，并且在蛋白质水平上定量。 水平使用Western印迹、FACS和放射受体分析。此外，委员会认为， 与IL-12RB2缺失相关的T淋巴细胞功能的降低将 评估，并对发展中的TH1和TH2淋巴细胞进行功能评估 将通过以下STAT-4激活和T-bet、加塔-3和c-maf测定 mRNA表达。受感染的树突状细胞是否可以诱导这种 还将测定CD4 + T细胞的改变。综合这些 研究代表了第一个定义细胞内 细菌病原体可不利地影响TH1的早期发育 淋巴细胞感染。