The role of Th17 cytokines in H.pylori infection

描述（由申请人提供）： 对幽门螺杆菌的免疫反应在清除感染方面是无效的，但在大多数情况下，它成功地限制了细菌的增殖，并且大多数幽门螺杆菌感染者的免疫反应是无效的。幽门感染者仍无症状。T辅助细胞17对H.幽门螺杆菌是控制感染所必需的，但也控制炎症和免疫细胞迁移。我们自己的研究已经确定IL-17信号转导是宿主对H.幽门螺杆菌和一个强有力的候选人之间的联系T细胞活性和效应功能。IL-17调节细菌-宿主相互作用的机制还不完全清楚。探讨T辅助细胞17细胞因子，包括IL-17 A、IL-17 F和IL-22在H. pylori感染是特别有趣的，因为H.幽门螺杆菌是一种持续性感染，可引致消化性溃疡及胃癌等不良后果。公认IL-17诱导上皮细胞中趋化因子表达以募集中性粒细胞，但由于IL-17的受体IL-17 RA在许多细胞类型上表达，包括上皮细胞、粒细胞和淋巴细胞，因此其作用甚至更广泛。具体的目的是阐明由Th 17细胞产生的细胞因子对上皮细胞和中性粒细胞反应的相对贡献，特别是在H.幽门感染和胃炎。我们将（1）研究IL-17和IL-22细胞因子在H.幽门感染此外，我们将（2）确定IL-22在控制细菌定植和维持H. pylori感染，以及（3）确定IL-17是否对H.幽门感染除了加深我们对H.幽门螺杆菌感染，这些实验将有助于我们了解与粘膜感染和免疫介导的疾病，如银屑病，炎症性肠病和类风湿性关节炎相关的免疫病理学。

DESCRIPTION (provided by applicant): The immune response to Helicobacter pylori is ineffective in clearing infection, but in most cases it successfully restricts bacterial proliferation, and most H. pylori-infected persons remain asymptomatic. A T helper 17 response to H. pylori is required for control of infection, but also controls inflammation and immune cell migration. Our own studies have identified IL-17 signaling as an essential regulator of the host response to H. pylori and a strong candidate for a link between T cell activity and effector functions. The mechanisms by which IL-17 regulates bacterial- host interactions are not completely understood. Addressing the role of T helper 17 cytokines, including IL-17A, IL-17F, and IL-22, during H. pylori infection is particularly interesting because H. pylori is a persistent infection which can lead to adverse outcomes including peptic ulcers and gastric cancer. It is well accepted that IL-17 induces chemokine expression in epithelial cells for the recruitment of neutrophils, but since the receptor for IL-17, IL-17RA, is expressed on many cell types, including epithelial cells, granulocytes, and lymphocytes, its effects are even more widespread. The specific aims are designed to elucidate the relative contributions of cytokines produced by Th17 cells to the epithelial cell and neutrophil response and specifically in control of H. pylori infection and gastritis. We will (1) investigate the role of IL-17 and IL-22 cytokines in stimulating gastric epithelial cell expression of antimicrobial products during H. pylori infection. Moreover, we will (2) determine the role of IL-22 in control of bacterial colonization and maintenance of barrier function during H. pylori infection, and (3) determine whether IL-17 has a direct effect on neutrophil activation during H. pylori infection. In addition to enhancing our understanding of H. pylori infection, these experiments will contribute to our understanding of the immune pathology associated with mucosal infections and immune- mediated diseases, such as psoriasis, inflammatory bowel disease, and rheumatoid arthritis.