Regulation of vaccine-induced anti-fungal T17 cells

描述(申请人提供)：在过去的一个世纪里，传染病疫苗被誉为公共卫生领域最伟大的成就。尽管严重的真菌感染日益流行，但目前还没有针对真菌的疫苗处于临床试验或商业可用状态。我们已经设计出一种减毒活疫苗，可以预防主要真菌病原体皮炎芽孢杆菌的感染。我们和其他人已经证明，疫苗对这种和其他真菌感染的免疫是由显性的T1细胞反应介导的。在初步数据中，我们发现T17细胞也被疫苗诱导，并对皮炎杆菌以及相关的二相性真菌Poccidioids posadasii和组织胞浆菌产生抗药性。与流行的教条相反，我们观察到T1细胞，而不是T17细胞，在这种疫苗耐药性中是可有可无的，而且T17细胞也足以产生耐药性。疫苗诱导的T17细胞通过招募和激活中性粒细胞和肺泡巨噬细胞到肺泡腔来增强对真菌的杀灭，从而介导保护。在这一应用中，我们建议破译诱导幼稚抗原特异性T细胞分化为保护性抗真菌T17细胞的细胞受体和固有信号通路。我们创造了一种新型的Blastomyces 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细胞的分化需求。我们推测，FcR3-Syk-CARD9和TLR-MyD88信号通路对甘露聚糖芽胞杆菌的受体识别是诱导T17细胞和疫苗免疫所必需的。我们还推测，MyD88诱导的T17细胞分化涉及TLRs和CARD9之间的通路串扰，TLRs与甘露糖受体协同诱导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。使用我们新的Blastomyces特异性TCRTG小鼠，我们已经建立了来自基因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，以描述诱导幼稚抗原特异性CD4+T细胞分化为保护性T17细胞的信号适配器、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补充策略，将研究AIM 1和2中的宿主受体和信号通路，以及AIM 3中的真菌配体。我们的工作将为了解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。这一知识将为开发和设计新的抗真菌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佐剂。

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.