MHC-II deficient Langerhans cells with compensatory Tc17 plasticity in oral candidiasis

7.项目摘要/摘要 口咽念珠菌病可演变为严重的系统性感染，发病率和死亡率在 手术后和免疫功能低下的患者。对其免疫致病机制的透彻理解是 对于改进减轻或预防这种疾病的治疗至关重要。已知IL-17A由先天提供 而依赖于CD4的获得性免疫反应是控制白色念珠菌(CA)入侵和 散开。目前尚不清楚的是粘膜抗原提呈细胞所起的作用。 朗格汉斯细胞(LCS)对产生IL-17A的代偿性CD8+T细胞群发育的影响 (TC17)对口腔念珠菌病有潜在保护作用的化合物。在动态平衡时，缺乏LCS或MHC-II 在LC上的演示，扩大了TC17的人口。我们的长期目标是识别和描述 本地免疫成分对机会性微生物的反应最终保护 口腔粘膜表面疾病的个体。我们有初步数据表明， LCS和MHC-II呈递LCS导致Tc17、Tc1和Treg细胞在 动态平衡。我们目前的目标是确定LC如何控制胃粘膜Tc17细胞的数量 当Tc17存在时，MHC-II依赖的方式和对CA的保护程度。我们 假设上皮内LC调节Tc17的数量作为IL-17A和a的代偿来源 产生干扰素-的Tc1的储存库，有助于有效地防御慢性CA感染。测试我们的 假设，我们将首先确定LC是否需要迁移到淋巴结才能诱导MHC-II依赖 口服Tc17的抑制作用。其次，确定是否需要IL-6/STAT3或转化生长因子-来推动TC17持久性和 口腔黏膜对Tc1的体内可塑性。据我们所知，我们是第一个定义 MHC-II在LCS上的表达是口腔黏膜Tc17扩张的关键因素。我们优化了间隙 口腔粘膜中白细胞的分类、计数和表型鉴定，不包括血液和鼻腔粘膜 相关淋巴组织。关键的是，我们可以毫不含糊地永久地标记表型和 表达IL-17A的CA特异性CD3+T细胞的发育命运评估其表型可塑性。我们的 该策略采用了报告和沉默小鼠品系的基因杂交。我们可以使用MHC-I和MHC-II 四聚体能够唯一识别“表位标记”CA菌株的CD8+和CD4+T细胞。 我们希望确定LCS作为发育重新编程CA特异性Tc17的调节因子的作用 口腔粘膜或颈淋巴结内的Tc1细胞。更深刻地理解了 引发口腔念珠菌病的机制通过治疗干预来操纵钥匙 采取措施，减轻或预防系统性念珠菌病。

7. PROJECT SUMMARY / ABSTRACT Oropharyngeal candidiasis can evolve into serious systemic infections with high morbidity and mortality rates in post-surgical and immunocompromised patients. A thorough understanding of its immunopathogenesis is critical to improve therapies that mitigate or prevents this disease. It is known that IL-17A provided by innate and CD4-dependent adaptive immune responses is key to controlling Candida albicans (CA) invasion and spread. What remains unknown is the role played by mucosal antigen presenting cells, in particular Langerhans cells (LCs), on the development of compensatory IL-17A-producing CD8+ T cell populations (Tc17) that are potentially protective against oral candidiasis. At homeostasis, lack of LCs or MHC-II presentation on LC, expands the Tc17 population. Our long-range goal is to identify and characterize the response to opportunistic microorganisms by components of the local immune that ultimately protect individuals from diseases at oral mucosal surfaces. We have preliminary data that suggests that absence of LCs and MHC-II presentation on LCs results in the secondary clonal expansion of Tc17, Tc1 and Treg cells at homeostasis. Our current objectives are to determine how LCs control the numbers of mucosal Tc17 cells in an MHC-II dependent manner and the extent of protection against CA when Tc17 are present. We hypothesize that intraepithelial LCs regulate the numbers of Tc17 as a compensatory source of IL-17A and a reservoir of IFN--producing Tc1 contributing to an efficient barrier against chronic CA infection. To test our hypothesis, we will first determine if migration to lymph nodes is required for LCs to induce MHC-II-dependent inhibition of oral Tc17. Second, determine if IL-6/STAT3 or TGF- are required to drive Tc17 persistence and plasticity to Tc1 in the oral mucosa in vivo. To the best of our knowledge, we are the first group to define MHC-II presentation on LCs as key factor in Tc17 expansion in the oral mucosa. We optimized interstitial leukocytes sorting, enumeration and phenotype assessment from the oral mucosa excluding blood or nasal- associated lymphoid tissues. Critically, we can unequivocally and permanently mark the phenotype and developmental fate of IL-17A-expressing CA-specific CD3+ T cells assessing their phenotypic plasticity. Our strategy employs genetic crossing of reporter- and silencing- murine strains. We can use MHC-I and MHC-II tetramers capable of uniquely recognizing CD8+ and CD4+ T cells specific for an "epitope-tagged” CA strain. We expect to determine the role of LCs as regulators of the developmental re-programming CA-specific Tc17 to Tc1 cells either in the oral mucosa or cervical lymph nodes. With a deeper understanding of the mechanisms initiating oral candidiasis comes opportunities through therapeutic interventions to manipulate key steps and mitigate or prevent systemic candidiasis.