Th17 subsets: Differential roles in immune defense mechanisms at the G-I mucosa

描述(申请人提供)：在研究粘膜佐剂霍乱毒素时，我们最近发现它通过cAMP信号诱导Th17细胞分化。规范性(即IL-6/TGF)和非规范性(即cAMP)Th17亚群表现出不同的细胞因子归巢受体，并受不同的转录因子组合调控。我们假设这两个Th17亚群执行不同的生理任务，特别是在粘膜部位。为了研究这些Th17亚群在G-L粘膜中的免疫保护性和免疫致病性，我们提出了4个特异性靶点(SA)。在SA-1中，我们将描述和比较体外产生的Th17亚群在过继转移到受体小鼠后的表型。同样，我们将在结肠炎模型中评估每个Th17亚群的炎症与调节功能。为了探索cAMP信号在体内Th17分化中的生理作用，我们建立了携带CD4T细胞中刺激性GA蛋白(GSA)特异性缺失的Ko小鼠(GsaCD4Ko小鼠)。因此，在SA-2中，我们将评估GsaCD4Ko CD4T细胞的细胞因子谱，它们对淋巴器官和G-L粘膜的归巢特性，以及它们在肠道炎症模型中的结肠性。在SA-3中，我们将评估GsaCD4Ko CD4T细胞是否介导宿主对微生物病原体的保护作用，即轮状念珠菌和幽门螺杆菌。我们将研究非规范Th17细胞在宿主防御、粘膜保护和粘膜炎症中的功能。这些研究的一个重要的翻译应用是设计以cAMP为基础的药理学干预措施，其目标是调节粘膜部位的CD4T细胞功能。因此，在SA-4中，我们将确定在上述动物模型中，cAMP升高药物的管理是否调节粘膜防御。我们拟议的研究结果可以促进未来疫苗和免疫疗法的设计和开发，旨在保护不同的粘膜表面免受感染和免疫介导的病理，这是本RFA的最终目标。

DESCRIPTION (provided by applicant): While studying the mucosal adjuvant, cholera toxin, we recently identified It Induces Th17 cell differentiation via cAMP signaling. Canonical (I.e., induced by IL-6/TGF¿) and non-canonical (i.e., induced by cAMP) Th17 subsets display different cytokine homing receptors and are regulated by different combinations of transcription factors. We hypothesize that these two Th17 subsets perform different physiological tasks especially at mucosal sites. To characterize the immunoprotective vs. immunopathogenic profiles of these Th17 subsets in the G-l mucosa, we proposed 4 specific aims (SA). In SA-1 we will characterize and compare the phenotype of the in vitro generated Th17 subsets after their adoptive transfer to recipient mice. Similarly, we will assess the inflammatory vs. regulatory function of each Th17 subset in a model of colitis. To explore the physiological role of cAMP signaling in Th17 differentiation in vivo, we generated ko mice that carry a specific deletion of the stimulatory Ga protein (Gsa) in CD4 T cells (GsaCD4 ko mice). Thus, in SA-2 we will evaluate the cytokine profile of GsaCD4 ko CD4 T cells, their homing properties to lymphoid organs and G-l mucosa, and their colitogenic profile in models of intestinal inflammation. In SA-3 we will evaluate whether GsaCD4 ko CD4 T cells mediate host protection against microbial pathogens, i.e., C. rodentium and H. pylori. We will examine the function of non-canonical Th17 cells in host defense, mucosal protection and mucosal inflammation. An important translational application of these studies is the design of cAMP-based pharmacological interventions that target the regulation of CD4 T cell functions in mucosal sites. Thus, in SA- 4 we will determine whether the administration of cAMP-elevating drugs regulate mucosal defense in the animal models described above. The results from our proposed research can facilitate the future design and development of vaccines and immunotherapies aimed at the protection of different mucosal surfaces from infections and immune-mediated pathology, which are the ultimate objectives of this RFA.