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

项目摘要/摘要 CD4细胞毒性T淋巴细胞(CTL)在稳态时积聚在小肠上皮细胞中，但其 在这个障碍上的发展和目的(S)在很大程度上是未知的。CD4CTL对小鼠的独特定位 肠上皮提示组织特异性，引导CD4CTL从幼稚的CD4T辅助细胞发育而来 (Th)细胞。 与传统的髓系抗原提呈细胞类似，肠上皮细胞表达MHC-II类 (MHCII)，提示可能对附近的CD4T细胞产生影响。此外，IECS还在不断处理 腔内容物，并应将耐受性抗原(例如，饮食或共生菌衍生的)呈现给 CD4T细胞位于基底外侧。我已经生成了MHCII-饮食加工的初步证据 IECS的抗原参与了CD4CTL在小肠上皮细胞的蓄积。 在这一发现的基础上，我假设上皮细胞在调节CD4Th细胞转换方面起着直接作用 转化为CD4CTL。由此产生的CD4CTL群体进一步被预测具有非冗余的保护作用 对抗食源性病原体。综上所述，上皮CD4CTL的存在可能代表了一种免疫 同时增加一只防御手臂，同时提供另一种形式的免疫调节的战略。 拟议的研究有望对粘膜CD4T细胞免疫学产生新的见解，这可能是 与预防或治疗胃肠道疾病以及改进疫苗开发有关 战略。 我建议结合使用条件性基因敲除小鼠模型和沙门氏菌病原体模型 使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IECS作为抗原提呈细胞在将CD4Th细胞重新编程为CD4CTL中的作用以及 这些CD4CTL在稳态或感染期间的功能作用。所有实验都将在 拉霍亚免疫学研究所是生物医学科学研究的领先者，在赞助商Dr。 Hilde Cheroutre和共同赞助人Mitchell Kronenberg博士。此外，我将接受专业指导和 来自我的合作者和论文委员会的支持进行研究。我作为一名科学家的成长也将 辅以通过加州大学圣地亚哥分校生物医学博士项目举办的课程和活动。 总而言之，本次F31奖项申请的拟议研究和培训目标旨在 培训我成为一名多才多艺的独立研究员，拥有黏膜免疫学专业和强大的 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.