γδT17细胞协同Th17细胞应答在幽门螺杆菌感染致慢性胃炎中的作用及机制研究

T细胞应答在幽门螺杆菌（Hp）感染所致慢性胃炎、胃溃疡中起重要作用，但确切机制仍未阐明。γδT17细胞为新近发现的一群以分泌IL-17为主的γδT细胞，可直接识别病原体并迅速发挥免疫效应。我们前期研究显示：Hp感染早期γδT17细胞显著增高，后期则以Th17细胞为主。Th17细胞通过分泌IL-17促进Hp感染并加剧炎症反应。而γδT细胞可调节获得性免疫应答参与疾病进程，我们推测早期γδT17细胞可能通过分泌IL-17直接参与或(和) 间接通过调控Th17应答并协同其促进了Hp感染的致病过程。本项目拟以γδT17细胞为主要研究对象，采用WT及IL-17-/-的γδT细胞过继转移模型，抗体阻断，Vγ4γδT细胞删除等方法，研究γδT17细胞应答对Th17细胞的免疫调控，及其对Hp感染致胃炎的影响。明确γδT17细胞在Hp感染中的作用，对Hp感染致慢性胃炎的免疫防治具有重要的指导意义。

T cell response plays an important role in the process of Hp-induced chronic gastritis and ulcer, but the exact mechanism is still not clear. γδT17 cells, mainly secreting IL-17, are a newly discovered subset of γδT cells, which could response to the bacteria infection very quickly and modulate adaptive immune response to combat the infection. Our previous data showed that Hp infection could induce γδT17 cell response at the early stage and Th17 cell response in the late stage. Th17 cells promote Hp-induced chronic gastric inflammation by secreting IL-17. Therefore we speculate that γδT17 cells may also promote Hp-induced chronic inflammation directly or indirectly via regulating Th17 cell response. In this project we will focus on γδT17 cells and try to illustrate its role in Th17 cell regulation and its impact on Hp-induced chronic inflammation using methods of adoptive transfer of γδT cells, antibody blocking, Vγ4γδT cell depletion and etc. Depicting the role of γδT17 cells in this process would be critical for us to better understand the immuno-pathogenesis of Hp-induced disease and find a more effective therapy to combat it.