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

酸性pH下胃粘膜对幽门螺杆菌感染的反应机制

• 批准号: 8913164
• 负责人: Elizabeth A. Marcus
• 金额: $ 15.24万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8913164
• 关键词: Acclimatization; Acidity; Acids; Acute; Advisory Committees; Amino Acids; Amoxicillin; Animal Model; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Atrophic Gastritis; Bacteria; Bacterial Physiology; Basic Science; Biological Models; California; Cell Culture Techniques; Cells; Childhood; Clarithromycin; Clinical; Coculture Techniques; Complex; Confocal Microscopy; Data; Development; Disease; Duodenal Ulcer; Environment; Epithelial; Epithelial Cell Junction; Epithelial Physiology; Epithelium; Eukaryotic Cell; Fellowship; Fostering; Gastric mucosa; Gastric ulcer; Gastritis; Gastroenterology; Genes; Gerbils; Goals; Health; Helicobacter Infections; Helicobacter pylori; Human; IL8 gene; Immune response; Immune system; Immunology; In Vitro; Infection; Infection prevention; Inflammation; Inflammatory Infiltrate; Inflammatory Response; Injury; Integration Host Factors; Intercellular Junctions; Knowledge; Lead; Life; Los Angeles; Malignant Neoplasms; Mass Spectrum Analysis; Mediator of activation protein; Mentors; Metronidazole; Microscopy; Modeling; Monitor; Mucositis; Outcome; Pathologic; Pathology; Pathway interactions; Patients; Pediatric Hospitals; Pediatrics; Peptic Ulcer; Permeability; Pharmaceutical Preparations; Physiological; Physiology; Population; Postdoctoral Fellow; Prevention; Prevention strategy; Principal Investigator; Process; Production; Program Development; Proteins; Proton Pump Inhibitors; Recording of previous events; Regimen; Research; Research Personnel; Residencies; Resistance; Risk; Role; Signaling Molecule; Stable Isotope Labeling; Stomach; Stomach Carcinoma; Stomach Diseases; System; Technology; Testing; Time; Training; Training Programs; Treatment Efficacy; Treatment Protocols; Ulcer; Universities; Virulence Factors; Work; advanced disease; base; career; career development; compliance behavior; cytokine; falls; graduate student; immune activation; improved; in vitro Model; in vivo; in vivo Model; infectious disease treatment; injured; instructor; malignant stomach neoplasm; medical schools; mucosa-associated lymphoid tissue lymphoma; novel; pathogen; pediatric department; professor; programs; research and development; research study; response; skills; success; treatment duration

DESCRIPTION (provided by applicant): This proposal describes a four-year basic science training program for the development of a career in academic Pediatric Gastroenterology. The principal investigator, Dr. Elizabeth A. Marcus, a Clinical Instructor in Pediatric Gastroenterolog 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. Candidate 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.

描述（由申请人提供）：该提案描述了一个为期四年的基础科学培训计划，旨在发展学术儿科胃肠病学的职业生涯。主要研究者 Elizabeth A. Marcus 博士是加州大学洛杉矶分校儿科胃肠病学临床讲师，预计截至 2013 年 7 月 1 日将获得助理教授头衔，并获得普通儿科和儿科胃肠病学委员会认证。她在洛杉矶儿童医院完成了儿科住院医师实习。她在医学院、住院医师实习和进修期间参与了基础科学研究，研究胃部病原体幽门螺杆菌的酸适应机制和细菌生理学。目前的提案纳入了一个新开发的不同研究重点，研究细菌和酸性 pH 值对胃粘膜的影响。本提案中概述的计划将为申请人提供良好的研究环境和受保护的时间，以获取实现成为独立研究者目标所需的技能。导师 George Sachs 博士是胃生理学、胃酸分泌以及与幽门螺杆菌酸适应相关的细菌因素方面的公认专家。萨克斯博士在指导研究生和博士后研究员方面有着悠久的历史，这些研究生和博士后研究员已成为独立研究者。共同导师 David Scott 博士将贡献幽门螺杆菌、显微镜检查、动物模型和真核细胞系统方面的专业知识。共同导师 Charalabos Pothoulakis 博士将提供炎症和粘膜免疫学方面的专业知识。咨询委员会将监督职业发展并提供免疫学、质谱和上皮生理学方面的额外培训。儿科已经向申请人承诺了75%的受保护研究时间。加州大学洛杉矶分校提供了丰富的研究和学术环境，将促进研究独立性的发展。 拟议的研究重点是幽门螺杆菌如何与胃酸协同损伤胃粘膜并引发晚期疾病的发展。幽门螺杆菌感染在世界范围内非常普遍，至少会导致胃部炎症。其中一些感染者会发展为胃或十二指肠溃疡、胃萎缩和癌症。随着抗生素耐药性的出现以及患者对复杂治疗方案的依从性问题，治疗变得更加困难。尽管已经研究了多种细菌和宿主因素，但尚不清楚细菌如何逃避免疫系统，导致终身感染，或哪些因素导致晚期疾病的发展。该提案将使用与宿主环境具有生理相似性的体外和体内模型系统来确定上皮变化和免疫反应的改变。使用 SILAC（细胞培养中氨基酸稳定同位素标记）技术的定量质谱分析将用于研究细胞连接处的蛋白质变化，首先响应酸性，然后响应幽门螺杆菌感染。候选蛋白质或途径将被抑制以确认参与。共聚焦显微镜将用于进一步研究酸性 pH 共培养中的细胞连接。将表征细胞层电阻和渗透性变化。与 Th1 和 Th17 免疫反应有关的介质将在幽门螺杆菌感染和酸性 pH 值的背景下进行研究。幽门螺杆菌基因 将研究酸和沙鼠模型中表达的增加作为免疫反应的潜在调节剂。使用新型酸阻滞剂对受感染的沙鼠进行有效的酸抑制，将用于确定对细菌负荷、炎症浸润和细胞因子产生的影响。预计这项工作将增进对胃损伤机制的理解，并将导致针对感染及其对宿主的短期和长期后果的新治疗靶点的开发。