The Role of Intestinal Epithelial Cells in the Generation of Protective CD4 Cytotoxic T Lymphocytes

项目总结/摘要 CD4细胞毒性T淋巴细胞（CTL）在稳态时在小肠上皮中积累，但其 这一屏障的发展和目的基本上是未知的。CD4 CTL的独特定位于小细胞 肠上皮细胞提示了组织特异性的特性，其指导CD4 CTL从初始CD4辅助性T细胞发育 (Th)细胞 与传统的髓样抗原呈递细胞相似，肠上皮细胞（IEC）表达MHCII类抗原 （MHCII），表明可能影响附近的CD4 T细胞。此外，IEC还不断处理 管腔内容物，并预期呈递耐受性抗原（例如饮食或肠道细菌来源）， CD4 T细胞位于基底外侧。我已经产生了初步的证据，MHCII处理饮食 通过IEC的抗原参与CD4 CTL在小肠上皮中的积累。 基于这一发现，我推测上皮细胞在调节CD4 Th细胞转化中具有直接作用 转化为CD4 CTL。进一步预测得到的CD4 CTL群具有非冗余的保护作用 对抗食源性病原体综上所述，上皮细胞CD4 CTL的存在可能代表免疫应答。 这一策略同时增加了一个防御武器，同时提供了一种替代形式的免疫调节。 这些拟议的研究预计将对粘膜CD4 T细胞免疫学产生新的见解， 与预防或治疗胃肠道疾病以及改进疫苗开发相关 战略布局 我建议使用条件性基因敲除小鼠模型和沙门氏菌病原体模型的组合 采用最先进的流式细胞术、下一代测序和高分辨率显微镜进行分析， 确定IEC作为Ag呈递细胞在将CD4 Th细胞重编程为CD4 CTL中的作用， 这些CD4 CTL在稳态或感染期间的功能作用。所有实验将在 拉霍亚免疫学研究所，在生物医学科学研究的领导者，在赞助商博士的指导下。 Hilde Cheroutre和共同赞助人Mitchell Kronenberg博士。此外，我将接受专业指导， 我的合作者和论文委员会在执行研究方面的支持。我作为一名科学家的成长也将 通过在加州大学圣地亚哥分校生物医学博士课程举行的课程和活动进行补充。 总之，本次F31奖学金申请的拟议研究和培训目标是面向 培养我成为一个多才多艺的独立研究人员，在粘膜免疫学和强大的专业 科学的敏锐

PROJECT SUMMARY/ABSTRACT CD4 cytotoxic T lymphocytes (CTL) accumulate in the small intestinal epithelium during steady state, but their development and purpose(s) at this barrier are largely unknown. The unique localization of CD4 CTL to the small intestinal epithelium suggests tissue-specific properties that direct CD4 CTL to develop from naive CD4 T helper (Th) cells. Similar to traditional myeloid antigen-presenting cells, intestinal epithelial cells (IECs) express MHC class II (MHCII), suggesting a possible influence over nearby CD4 T cells. In addition, IECs are constantly processing luminal contents and are expected to present tolerized antigens (e.g. diet or commensal bacteria-derived) to CD4 T cells at its baso-lateral side. I have generated preliminary evidence that MHCII-processing of dietary antigens by IECs is involved in the accumulation of CD4 CTL in the small intestinal epithelium. Building on this finding, I hypothesize that the epithelium has a direct role in regulating CD4 Th cell conversion into CD4 CTL. This resulting CD4 CTL population is further predicted to have a non-redundant protective role against foodborne pathogens. Taken together, the presence of epithelial CD4 CTL could represent an immune strategy that simultaneously adds an arm of defense while providing an alternative form of immunoregulation. The proposed studies are expected to yield novel insights on mucosal CD4 T cell immunology that could be relevant for the prevention or treatment of gastrointestinal diseases as well as improving vaccine development strategies. I propose to use a combination of conditional knock-out mouse models and a Salmonella pathogen model analyzed with state-of-the-art flow cytometry, next-generation sequencing, and high-resolution microscopy to determine the role of IECs as Ag-presenting cells in reprogramming CD4 Th cells into CD4 CTL and the functional roles of these CD4 CTL during steady state or during infection. All experiments will be performed at La Jolla Institute for Immunology, a leader in biomedical science research, under the guidance of sponsor Dr. Hilde Cheroutre and co-sponsor Dr. Mitchell Kronenberg. In addition, I will receive professional guidance and support from my collaborators and thesis committee in performing the studies. My growth as a scientist will also be supplemented with classes and events held through the Biomedical Sciences PhD program at UC San Diego. In summary, the proposed studies and training objectives of this F31 award application are geared towards training me as to become a versatile independent researcher with a specialty in mucosal immunology and strong scientific acumen.