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: 6632243
• 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 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6632243
• 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)：实现最佳的关键驱动力 辅助性T细胞1型(TH1)的发育通过IL-12传递信号 受体。IL-12受体由两个亚基组成，表达 IL-12受体β2链(IL-12RB2)决定高亲和力IL-12 受体复合体。通过这种高亲和力的IL-12受体控制的信号 TH1淋巴细胞的发育和这种表型的维持，而 限制TH2表型的谱系承诺。因为TH1淋巴细胞在 细胞免疫，而TH2淋巴细胞增强体液反应，早期 高亲和力IL-12受体的表达对于承诺 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，可能还有树突状细胞，需要 细胞免疫清除。基于最近发表的研究成果，我们 表明感染沙门氏菌的巨噬细胞可以显著限制 IL-12RB2在应答早期T淋巴细胞上的表达。这一发现已经 T淋巴细胞早期发育和承诺的深刻意义 在沙门氏菌感染期间与TH1血统的关系。这个项目的总体目标是 提案是定义沙门氏菌引起的减少的机制 IL-12RB2在体外和体内的表达。目前尚不清楚是否 诱导的IL-12RB2表达减少完全由可溶性蛋白介导 因素或需要巨噬细胞与T细胞接触。IL-12RB2表达将为 用定量RT-PCR在mRNA水平和在蛋白质水平进行定量 免疫印迹、流式细胞仪和放射受体分析。此外， 与IL-12RB2丢失相关的T淋巴细胞功能降低将 以及发育中的TH1和TH2淋巴细胞的功能评估 将由以下STAT-4激活以及T-BET、GATA-3和c-MAF确定 M RNA的表达。被感染的树突状细胞是否能诱导 还将确定CD4+T细胞的变化。把这些放在一起 研究表明，第一次定义了细胞内一种 细菌病原体可对TH1的早期发育产生不利影响 感染时的淋巴细胞。