Mechanisms of gastric mucosal response to H. pylori infection at acidic pH

项目摘要/摘要 这份提案描述了一项为期四年的基础科学培训计划，该计划旨在 学术儿科胃肠病学。首席研究员伊丽莎白·A·马库斯博士，临床讲师 加州大学洛杉矶分校的儿科胃肠病学博士，预计职称为助理 7/1/13年7月1日，教授获得了普通儿科和儿科胃肠病学委员会认证。她完成了 洛杉矶儿童医院儿科住院医师。她参与了基础科学研究，学习 胃部致病菌幽门螺杆菌的酸驯化机制及细菌生理 在医学院、住院医生和团契期间。目前的提案包含了一种新开发的 并分散研究重点，研究细菌和酸性pH对胃粘膜的影响。这个 该计划将为申请者提供良好的研究环境和 受保护的时间，以获得必要的技能，以实现她成为一名独立调查员的目标。这个 曼托博士乔治·萨克斯是公认的胃生理学、胃酸分泌和细菌因子专家。 与幽门螺杆菌酸适应有关。萨克斯博士在指导研究生方面有很强的历史 博士后研究员，他们已经发展成为独立的调查人员。共同导师大卫·斯科特博士 将在幽门螺杆菌、显微镜、动物模型和真核细胞系统方面贡献专业知识。共同导师Dr。 Charalabos Potulakis将提供炎症和粘膜免疫学方面的专业知识。忠告 委员会将监督职业发展并提供免疫学、质谱学等方面的额外培训 和上皮生理学。儿科部门已经承诺75%的受保护研究时间用于 申请人。加州大学洛杉矶分校提供了丰富的研究和学术环境，将促进 研究独立性。 这项拟议中的研究集中在幽门螺杆菌如何与胃酸一起损害人体健康。 胃粘膜并引发进展期疾病的发展。幽门螺杆菌感染非常普遍 在全世界范围内，至少会引起胃炎。一些感染者进展为胃部疾病 或十二指肠溃疡疾病、胃萎缩和癌症。随着疾病的出现，治疗变得更加困难 抗生素耐药性和患者对复杂治疗方案的依从性问题。它不是 确切地知道细菌是如何逃避免疫系统，导致终身感染的，或者什么 尽管多种细菌和宿主因素导致了晚期疾病的发生，但多种因素促进了晚期疾病的发展。 学习。这项建议将使用与宿主具有生理相似性的体外和体内模型系统 环境，以确定上皮的变化和免疫反应的变化。定量质量 将使用SILAC(细胞培养中氨基酸稳定同位素标记)技术进行光谱分析 研究细胞连接的蛋白质变化，首先是对酸性的反应，然后是对幽门螺杆菌感染的反应。候选人 蛋白质或通路将被抑制，以确认参与其中。将使用共聚焦显微镜进行进一步研究 在酸性pH条件下共培养时，细胞连接。细胞层的阻力和渗透率会发生变化 特色化的。参与Th1和Th17免疫反应的介体将在H. 幽门螺杆菌感染和酸性pH。在酸性和沙土鼠模型中表达增加的幽门螺杆菌基因将是 被认为是免疫反应的潜在调节剂。一种新型酸阻滞剂对感染患者的有效抑酸作用 沙土鼠将被用来确定对细菌负荷、炎性渗透和细胞因子的影响 制作。预计这项工作将增加对胃损伤机制的理解和 将导致针对感染及其短期和长期治疗目标的发展 给东道主带来的后果。

Project Summary/Abstract This proposal describes a four-year basic science training program for the development of a career in academic Pediatric Gastroenterology. The prinicpal investigator, Dr. Elizabeth A. Marcus, a Clinical Instructor in Pediatric Gastroenterology at the University of California, Los Angeles with a projected title of Assistant Professor as of 7/1/13, is board-certified in General Pediatrics and Pediatric Gastroenterology. She completed Pediatrics residency at Children's Hospital Los Angeles. She participated in basic science research, studying the acid acclimation mechanisms and bacterial physiology of the gastric pathogen Helicobacter pylori throughout medical school, residency, and fellowship. The current proposal incorporates a newly developed and divergent research focus, studying the effect of the bacteria and acidic pH on the gastric mucosa. The program outlined in this proposal will provide the applicant with an excellent research environment and protected time to attain the skills needed to achieve her goal of becoming an independent investigator. The mentor, Dr. George Sachs, is a recognized expert in gastric physiology, acid secretion, and bacterial factors associated with H. pylori acid acclimation. Dr. Sachs has a strong history of mentoring graduate students and postdoctoral fellows who have progressed to become independent investigators. Co-mentor Dr. David Scott will contribute expertise on H. pylori, microscopy, animal models, and eukaryotic cell systems. Co-mentor Dr. Charalabos Pothoulakis will provide expertise on inflammation and mucosal immunology. An advisory committee will monitor career development and provide additional training in immunology, mass spectrometry and epithelial physiology. The Department of Pediatrics has already committed 75% protected research time to the applicant. UCLA provides a rich research and academic environment that will foster the development of research independence. The proposed research focuses on how H. pylori, in coordination with gastric acidity, is able to injure the gastric mucosa and trigger development of advanced disease. H. pylori infection is highly prevalent worldwide and at a minimum causes gastric inflammation. Some of those infected progress to develop gastric or duodenal ulcer disease, gastric atrophy, and cancer. Treatment is becoming more difficult with emerging antibiotic resistance and problems with patient compliance with a complex treatment regimen. It is not definitively known how the bacteria are able to evade the immune system, leading to lifelong infection, or what factors contribute to development of advanced disease, although multiple bacterial and host factors have been studied. This proposal will use in vitro and in vivo model systems with physiologic similarities to the host environment to determine epithelial changes and alterations in immune response. Quantitative mass spectrometry using SILAC (Stable Isotope Labeling by Amino acids in Cell culture) technology will be used to study protein changes in the cell junction in response first to acidity, then to H. pylori infection. Candidiate proteins or pathways will be inhibited to confirm involvement. Confocal microscopy will be used to further study the cell junctions in co-culture with acidic pH. Cell layer resistance and permeability changes will be characterized. Mediators involved with the Th1 and Th17 immune responses will be studied in the context of H. pylori infection and acidic pH. H. pylori genes with increased expression in acid and in a gerbil model will be studied as potential modulators of immune response. Potent acid inhibition with a novel acid blocker in infected gerbils will be employed to determine the effect on bacterial load, inflammatory infiltrate, and cytokine production. It is anticipated that this work will add to the understanding of the mechanisms of gastric injury and will lead to development of novel treatment targets for both the infection and its short and long term consequences to the host.