Dendritic cell heterogeneity and its role in pulmonary fungal infection

项目摘要 机会性真菌病原体烟曲霉（Aspergillus fumigatus）是免疫受损和免疫缺陷患者的主要健康问题， 重症患者，表现为从急性到慢性的各种肺部疾病。在这些 临床综合征、A.烟曲霉激发了多种适应性CD 4 T细胞反应，但其机制 这些不同的反应是如何引起的仍然是未知的。传统的树突状细胞（cDC）对于 感应和启动对这种真菌病原体的免疫反应，并且是多种T细胞的可能介质。 回答A。烟熏。最近的研究已经建立了cDC异质性的转录基础 通过单细胞分析，特别证明了cDC 2群体中的分裂，这被认为是 典型的抗原呈递细胞，表达MHC II类和引发CD 4 T细胞。我们现在分开 基于转录因子的差异表达，将cDC 2分为两个新的亚类-cDC 2A和cDC 2B T-bet和RORγt。此外，已知cDC 2的解剖学定位有助于空间定位。 与病原体衍生的产物共定位，从而允许有效的病原体感测、抗原摄取， 随后的CD 4 T细胞活化。根据A.烟曲霉和最近发现的 cDC 2异质性，我们的具体假设是，cDC 2A和cDC 2B亚群将不同地定位在 肺和引流淋巴结，并促进对A的不同适应性CD 4 T细胞反应类型。烟熏。 在这项研究中，我们研究了cDC 2亚群在临床相关的侵袭性小鼠模型中的功能， 肺曲霉病在具体目标1中，我们将定义cDC 2子集的时间和空间动态 急性期A.应用高含量免疫荧光方法和流式细胞术检测烟曲霉感染。 我们还将评估cDC 2A和cDC 2B的体外功能特性。在具体目标2中，我们将阐明 cDC 2亚群对A.通过实施遗传工具， 特异性消融cDC 2A和cDC 2B亚群并在体内建立其功能意义。另外通过 研究cDC 2A亚群特异性消融中其他免疫细胞亚群的空间重组， cDC 2B，我们可以确定它们在控制肺免疫的细胞回路中的意义。这项研究采用和 开发新的遗传工具，显微镜方法和计算方法，以产生系统级 了解肺免疫生物学和研究宿主-病原体相互作用。此外，这项建议是 为培训中的医生科学家量身定制，因为它调查了 cDC 2亚群诱导对临床相关病原体A的适应性免疫。烟曲霉菌， 抗真菌治疗策略和疫苗开发。

Project Summary The opportunistic fungal pathogen Aspergillus fumigatus is a major health concern in immunocompromised and critically ill patients, manifesting as a variety of pulmonary conditions ranging from acute to chronic. In these clinical syndromes, A. fumigatus elicits a diverse adaptive CD4 T cell response, but the mechanisms by which these varied responses are induced remains unknown. Conventional dendritic cells (cDCs) are crucial for sensing and initiating immune responses to this fungal pathogen and are the likely mediators of diverse T cell responses to A. fumigatus. Recent studies have established the transcriptional basis for cDC heterogeneity through single cell analyses, specifically demonstrating a division in the cDC2 population, which are considered the canonical antigen presenting cells, expressing MHC Class II and priming CD4 T cells. We now separate cDC2s into two novel subsets—cDC2A and cDC2B—based on differential expression of the transcription factors T-bet and RORγt, respectively. In addition, the anatomic positioning of cDC2s is known to facilitate spatial colocalization with pathogen-derived products allowing for efficient pathogen sensing, antigen uptake, and subsequent CD4 T cell activation. Based on the pathogenic properties of A. fumigatus and recent discoveries of cDC2 heterogeneity, our specific hypothesis is that cDC2A and cDC2B subsets will localize differently in lung and draining lymph node and facilitate different adaptive CD4 T cell response types to A. fumigatus. In this study, we investigate cDC2 subsets’ functionality in a clinically relevant murine model of invasive pulmonary aspergillosis. In Specific Aim 1, we will define the temporal and spatial dynamics of cDC2 subsets during acute A. fumigatus infection by applying high-content immunofluorescence methods and flow cytometry. We will also assess cDC2A and cDC2B functional properties in vitro. In Specific Aim 2, we will elucidate the direct impact of cDC2 subsets on adaptive immunity in A. fumigatus infection by implementing genetic tools to specifically ablate cDC2A and cDC2B subsets and establish their functional significance in vivo. In addition, by investigating spatial reorganization of other immune cell subsets in subset-specific ablation of cDC2A and cDC2B, we can identify their significance in cellular circuits governing lung immunity. This study employs and develops novel genetic tools, microscopy methods, and computational approaches to generate a systems level understanding of lung immunobiology and study host-pathogen interactions. Furthermore, this proposal is tailored for a physician-scientist in training, as it investigates the basic features of and mechanisms by which cDC2 subsets induce adaptive immunity to the clinically relevant pathogen A. fumigatus, with implications for anti-fungal therapeutic strategies and vaccine development.