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

7.项目概要/摘要 口咽念珠菌病可演变为严重的全身感染， 术后和免疫功能低下的患者。对其免疫发病机制的深入了解是 这对改善缓解或预防这种疾病的疗法至关重要。已知IL-17 A由先天性免疫缺陷病毒提供， 和CD 4依赖性适应性免疫应答是控制白色念珠菌（CA）侵袭的关键， 传播.目前尚不清楚的是粘膜抗原呈递细胞所起的作用，特别是 Langerhans细胞（LC）对产生代偿性IL-17 A的CD 8 + T细胞群发育的影响 （Tc 17），其对口腔念珠菌病具有潜在保护作用。在体内平衡时，缺乏LC或MHC-II LC的介绍，扩大了Tc 17的人口。我们的长期目标是识别和描述 局部免疫组分对机会性微生物的反应， 口腔粘膜表面的疾病。我们有初步数据表明， LC和LC上的MHC-II呈递导致Tc 17、Tc 1和Treg细胞的二次克隆扩增， 体内平衡我们目前的目标是确定LC如何控制粘膜Tc 17细胞的数量， MHC-II依赖性方式和Tc 17存在时对CA的保护程度。我们 假设上皮内LC调节Tc 17的数量作为IL-17 A的补偿来源， 产生IFN-γ的Tc 1的储库有助于对抗慢性CA感染的有效屏障。来测试我们 假设，我们将首先确定LC是否需要迁移到淋巴结以诱导MHC-II依赖性的淋巴结转移。 口服Tc 17的抑制。其次，确定IL-6/STAT 3或TGF-β是否需要驱动Tc 17持久性， Tc 1在口腔粘膜中的可塑性。据我们所知，我们是第一个定义 LC上的MHC-II呈递是口腔粘膜中Tc 17扩增的关键因素。我们优化了间隙 从口腔粘膜（不包括血液或鼻粘膜）中进行白细胞分选、计数和表型评估， 相关淋巴组织重要的是，我们可以明确和永久地标记表型， 表达IL-17 A的CA特异性CD 3 + T细胞的发育命运，评估其表型可塑性。我们 该策略采用报告基因和沉默基因鼠品系的遗传杂交。我们可以用MHC-I和MHC-II 能够独特识别对“表位标记的”CA菌株特异性的CD 8+和CD 4 + T细胞的四聚体。 我们期望确定LC作为发育重编程CA特异性Tc 17的调节剂的作用。 口腔粘膜或颈部淋巴结中的Tc 1细胞。更深入地了解 引发口腔念珠菌病的机制通过治疗干预来操纵关键的 步骤和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.