H. PYLORI-SPECIFIC REGULATORY T CELLS THAT LIMIT HOST RESPONSE

H. 限制宿主反应的幽门螺杆菌特异性调节 T 细胞

• 批准号: 6846053
• 负责人: THOMAS G BLANCHARD
• 金额: $ 22.65万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6846053
• 关键词: Helicobacter; T cell receptor; T lymphocyte; bacteria infection mechanism; bacterial vaccines; cell cell interaction; chronic disease /disorder; disease /disorder model; enzyme linked immunosorbent assay; flow cytometry; gastric mucosa; gastritis; genetically modified animals; helper T lymphocyte; host organism interaction; immune response; immunoregulation; inflammation; interleukin 10; laboratory mouse; leukocyte activation /transformation; peptic ulcer; polymerase chain reaction; receptor expression; tissue /cell culture

DESCRIPTION (provided by applicant): Helicobacter pylori (H. pylori) colonizes the human gastric mucosa and plays an etiologic role in the development of gastritis and peptic ulcer disease. Infection persists for life despite the induction of histologic gastritis and specific immune responses. Similar observations have been made in the H. pylori-mouse model. However, mice lacking either IL-10 or NADPH oxidase develop inflammation in response to H. pylori that is significantly more intense than infected wild type mice, and spontaneously clear the bacteria from the gastric mucosa. Additionally, eradication of H. pylori from immunized mice following challenge is also accompanied by more intense inflammation. Therefore, H. pylori may persist due to the inability of the host to develop sufficiently intense inflammation during infection. The induction of down-regulatory T-cells that prevent aberrant responses to noninvasive bacteria in the colon has been described. These mechanisms may be conserved along the gastrointestinal tract and may be active in the gastric mucosa. This proposal will test the hypothesis that activation of T-cells at the gastric mucosa during H. pylori infection induces IL-10 producing regulatory T cells that suppress the inflammatory response, thus allowing for persistent infection. A correlate of this hypothesis is that vaccination effectively bypasses this down-regulation by activating T-cells in lymphoid tissue where the induction of IL-10 producing T-cells is not favored. We will address this hypothesis by: 1) Characterizing surface markers and cytokine profiles of gastric T cell from infected and immune mice to distinguish regulatory T-cells from protective T-cells. Flow cytometry and ELISA spot assays will be used to examine freshly isolated T-cells. 2) Identify the factors in the gastric mucosa that contribute to the induction of these regulatory cells. Transgenic mice and co-culture models will be used to explore the relationship of specific co-receptors and cytokines to T-cell activation in the stomach. 3) Investigate how regulatory T-cells interact with other cells to down-regulate inflammation. Regulatory T-cells will be studied in mice and in vitro to define the extent of their regulatory properties. These studies will increase our understanding of gastrointestinal immunoregulation and the design of better immunotherapies.

描述（由申请人提供）：幽门螺杆菌（H.幽门螺杆菌）定植于人胃粘膜中，并在胃炎和消化性溃疡疾病的发展中起病原学作用。感染持续终身，尽管诱导组织学胃炎和特异性免疫反应。 在H.幽门-小鼠模型。然而，缺乏IL-10或NADPH氧化酶的小鼠对H. pylori，其比感染的野生型小鼠显著更强烈，并且自发地从胃粘膜清除细菌。此外，根除H.攻击后来自免疫小鼠的幽门螺杆菌也伴随着更强烈的炎症。因此，H.由于宿主在感染过程中不能产生足够强烈的炎症，因此幽门螺杆菌感染可能持续存在。已经描述了在结肠中诱导下调T细胞以防止对非侵入性细菌的异常应答。这些机制可能是保守的沿着胃肠道，并可能是积极的胃粘膜。这一提议将检验H.幽门螺杆菌感染诱导产生抑制炎症反应的调节性T细胞IL-10，从而导致持续感染。该假设的相关性在于，疫苗接种通过激活淋巴组织中的T细胞而有效地绕过了这种下调，在淋巴组织中不有利于诱导产生IL-10的T细胞。 我们将通过以下方式解决这一假设：1）表征来自感染和免疫小鼠的胃T细胞的表面标志物和细胞因子谱，以区分调节性T细胞和保护性T细胞。 流式细胞术和ELISA斑点试验将用于检查新鲜分离的T细胞。2)确定胃粘膜中有助于诱导这些调节细胞的因子。转基因小鼠和共培养模型将用于探索特异性共受体和细胞因子与胃中T细胞活化的关系。3)研究调节性T细胞如何与其他细胞相互作用以下调炎症。将在小鼠和体外研究调节性T细胞，以确定其调节特性的程度。 这些研究将增加我们对胃肠道免疫调节的理解，并设计更好的免疫疗法。