T Cell Initiated Gastric Pathology

描述（由申请人提供）：幽门螺杆菌是一种主要病原体，除了感染世界上一半以上的人口外，还与胃和十二指肠溃疡疾病、粘膜相关淋巴瘤和腺癌有关。螺杆菌感染幽门螺杆菌导致中性粒细胞、巨噬细胞、CD 4 + T细胞和B细胞的早期胃浸润。这些胃浸润伴随着胃IFN-γ、TNF-α和IL-1水平的增加以及胃壁细胞、酶原细胞和胃粘膜细胞发育不良的丧失。关于这种胃浸润诱导随后的胃上皮病理学的机制知之甚少。一个小的动物模型的螺杆菌感染，H。猫小鼠模型，在感染后发生严重胃萎缩和胃腺癌方面与人类疾病非常相似。该模型允许仔细分析对螺杆菌感染的适应性免疫应答。利用一种新的过继性疾病转移模型，我们已经证明宿主CD 4 + T细胞应答对H.猫相关胃病理学。这使我们的注意力转向CD 4 + T细胞的作用，及其潜在的效应机制，在幽门螺杆菌相关的胃上皮细胞破坏和病理的发展。这项拨款申请的重点是假设招募和激活的CD 4 + T细胞在胃中的结果在继发性非抗原特异性胃上皮细胞的改变。上皮细胞增殖和分化的这些变化导致胃异型增生和癌形成。为了阐明这种免疫/上皮细胞关系及其后遗症，我们建议：1）表征对螺杆菌相关胃病理学发展至关重要的CD 4 + T细胞的抗原识别要求; 2）确定分泌或细胞表面产物在螺杆菌相关胃上皮病理学产生中的作用。这些研究将利用体内疾病模型以及新型原代胃上皮细胞培养系统。了解宿主对螺杆菌的免疫反应诱导胃上皮病理的基本机制将为进一步研究螺杆菌感染及其相关消化道疾病的炎症反应调控和免疫治疗设计奠定基础。

DESCRIPTION (provided by applicant): The bacteria Helicobacter pylori is a major pathogen which, in addition to infecting over half of the world's population, is linked to gastric and duodenal ulcer disease, mucosal-associated lymphomas, and adenocarcinoma. Infection with H. pylori results in an early gastric infiltration of neutrophils, macrophages, CD4+ T cells, and B cells. These gastric infiltrates are accompanied by increased levels of gastric IFN-gamma, TNF-alpha, and IL-1 and by loss of gastric parietal cells, zymogenic cells, and dysplasia of gastric mucosal cells. Very little is known about the mechanisms by which this gastric infiltrate induces subsequent gastric epithelial pathology. A small animal model of Helicobacter infection, the H. felis mouse model, closely mimics the human disease in that severe gastric atrophy and gastric adenocarcinoma develops after infection. This model has allowed a careful analysis of the adaptive immune response to Helicobacter infection. Using a novel adoptive transfer model of disease, we have shown that it is the host CD4+ T cell response which is crucial for the development of H. felis-associated gastric pathology. This has directed our attention to the role of the CD4+ T cell, and its potential effector mechanisms, in the development of Helicobacter-associated gastric epithelial cell destruction and pathology. This grant application focuses on the hypothesis that recruitment and activation of CD4+ T cells in the stomach results in secondary non-antigen specific gastric epithelial cell alterations. These changes in epithelial cell proliferation and differentiation lead to gastric dysplasia and cancer formation. In order to elucidate this immune/ epithelial cell relationship and its sequelae, we propose to: 1) characterize the antigen recognition requirements of the CD4+ T cell critical for the development of Helicobacter-associated gastric pathology; and 2) determine the role of secreted or cell-surface products in the generation of Helicobacter-associated gastric epithelial pathology. These studies will utilize both in vivo models of disease, as well as a novel primary gastric epithelial cell culture system. The understanding of the basic mechanisms by which the host immune response to Helicobacter induces gastric epithelial pathology will lay the foundation for further studies on the regulation of the inflammatory response and the design of immunotherapies for Helicobacter infection and associated digestive diseases.