Regulation of vaccine-induced anti-fungal T17 cells

描述（申请人提供）：传染病疫苗被誉为上世纪公共卫生领域最伟大的成就。尽管严重真菌感染的发病率不断增加，但没有针对真菌的疫苗处于临床试验或商业上可用。我们已经设计了一种减毒活疫苗，可以防止主要真菌病原体皮肤芽生菌的感染。我们和其他人已经表明，疫苗对这种和其他真菌感染的免疫是由显性T1细胞应答介导的。在初步数据中，我们发现T17细胞也被疫苗接种诱导并赋予对B的抗性。以及相关的二型真菌球孢子菌和荚膜组织胞浆菌。与流行的教条相反，我们观察到T1细胞，而不是T17细胞，在这种疫苗抗性中被破坏，并且T17细胞也足以产生抗性。疫苗诱导的T17细胞通过募集和激活中性粒细胞和肺泡巨噬细胞到肺泡腔来增强真菌杀伤而介导保护作用。 在本申请中，我们提出破译诱导幼稚抗原特异性T细胞分化为保护性抗真菌T17细胞的细胞受体和先天信号传导途径。我们已经创建了一种新型的Blastomestrin TCR转基因小鼠，这是一项关键的创新，将使我们能够分析幼稚抗真菌T细胞分化的要求。我们推测FcR3-Syk-Card9和TLR-Myd88信号通路对甘露聚糖芽生酵母的受体识别对于诱导T17细胞和疫苗免疫是必不可少的。我们还证实Myd 88诱导的T17细胞分化涉及TLR和Card9之间的通路串扰，并且TLR与甘露糖受体合作诱导T17细胞分化。我们提供了强有力的初步数据来支持我们的假设。使用我们的新的芽生菌特异性TCR Tg小鼠，我们已经建立了用来自敲除小鼠的骨髓来源的树突状细胞的体外筛选和体内过继转移系统，以描绘诱导幼稚抗原特异性CD4 + T细胞分化为保护性T17细胞的信号传导衔接子、病原体识别受体和真菌配体。我们的方法提供了一个强大的互补策略，将调查目标1和2中的宿主受体和信号传导途径，以及目标3中的真菌配体。我们的工作将为真菌病原体识别受体和下游信号通路以及诱导T17细胞分化的病原体相关分子模式提供新的见解。这些知识将为开发和设计针对真菌的新疫苗策略提供基本基础，并将催化发现可用于抗真菌和微生物疫苗的新型佐剂。 公共卫生相关性：在过去的10年里，真菌感染的数量在美国急剧上升，现在已经排在死亡原因的前10位，部分原因是我们缺乏针对真菌的疫苗。为了满足公众健康的需要，我们已经产生了一种减毒真菌疫苗，和一个实验模型来研究疫苗对真菌的免疫机制。在这个建议中，我们将确定宿主-病原体相互作用是疫苗诱导的抗性的基础。从这项研究中获得的知识将导致真菌疫苗和佐剂的发展。

DESCRIPTION (provided by applicant): Vaccines against infectious disease have been hailed as the greatest achievement in public health over the last century. Despite the growing prevalence of severe fungal infections, no vaccines against fungi are in clinical trials or commercially available. We have engineered a live attenuated vaccine that protects against infection with the primary fungal pathogen Blastomyces dermatitidis. We and others have shown that vaccine immunity to this and other fungal infections is mediated by a dominant T1-cell response. In preliminary data, we found that T17 cells also are induced by vaccination and confer resistance against B. dermatitidis as well as related dimorphic fungi Coccidioides posadasii and Histoplasma capsulatum. In contrast to the prevailing dogma, we observed that T1 cells, but not T17 cells, are dispensable in this vaccine resistance and that T17 cells are also sufficient for the resistance. Vaccine-induced T17 cells mediated protection by recruiting and activating neutrophils and alveolar macrophages to the alveolar space to augment fungal killing. In this application, we propose to decipher the cellular receptors and innate signaling pathways that induce naive antigen-specific T-cells to differentiate into protective anti-fungal T17 cells. We have created a novel Blastomyces TCR transgenic mouse, which represents a key innovation that will let us analyze the requirements for differentiation of naive anti-fungal T-cells. We hypothesize that receptor recognition of Blastomyces mannans by the FcR3-Syk-Card9 and the TLR-Myd88 signaling pathways are essential to induce T17 cells and vaccine immunity. We also posit that Myd88-induced T17 differentiation involves pathway crosstalk between TLRs and Card9, and that TLRs collaborate with the mannose receptor to induce T17 cell differentiation. We provide strong preliminary data to support our hypotheses. Using our new Blastomyces-specific TCR Tg mouse, we have established an in vitro screen with bone marrow derived dendritic cells from knockout mice and an in vivo adoptive transfer system to delineate the signaling adaptors, pathogen recognition receptors, and fungal ligands that induce differentiation of naive antigen-specific CD4+ T- cells into protective T17 cells. Our approach offers a powerful complimentary strategy that will investigate the host receptors and signaling pathways in Aims 1 and 2, and the fungal ligands in Aim 3. Our work will provide new insight into the fungal pathogen recognition receptors and downstream signaling pathways, as well as the pathogen-associated molecular patterns that induce T17 cell differentiation. This knowledge will provide the fundamental basis for developing and designing new vaccine strategies against fungi, and will catalyze the discovery of novel adjuvants useful in vaccines against fungi and microbes in general. PUBLIC HEALTH RELEVANCE: The number of fungal infections has risen dramatically in the United States over the last 10 years, and is now in the top 10 in causes of death, partly because we lack vaccines against fungi. To address that public health need, we have generated an attenuated fungal vaccine, and an experimental model to study mechanisms of vaccine immunity to fungi. In this proposal, we will identify the host-pathogen interactions that are the foundation of vaccine-induced resistance. The knowledge gained from this research will lead to the development of fungal vaccines and adjuvants.