Immunity against fungal infections

项目总结 尽管全球真菌感染呈上升趋势， 包括由特有种引起的 ..，目前还没有获得许可的真菌疫苗 可用。这主要是由于对疫苗免疫机制的了解不足，以及缺乏 功能界别 与表型相关的标记 疫苗的效力。机会性真菌感染，包括由 在这种危险中，二相性真菌、组织胞浆菌、球孢子菌和芽孢霉菌正在以惊人的速度上升 个人。为高危人群量身定做的真菌疫苗开发的一个主要限制是很差 了解 介导疫苗免疫所必需的CD8+T细胞反应要素。 的最新进展 对对抗真菌感染的免疫相关性的了解有助于并行推进疫苗学。 T细胞来源的IL-17A、干扰素γ、GM-CSF、IL-22和肿瘤坏死因子α主要参与对真菌的保护作用。 识别宿主细胞上的潜在靶点可以提供新的有效疫苗平台，包括 免疫功能受损。我们已经建立了一种CD4+T细胞淋巴细胞减少的小鼠模型，其中CD8+T细胞 可被刺激产生保护性细胞因子IL-17A(Tc17)和干扰素γ(Tc1)来执行杀菌免疫 对抗致命的肺部真菌感染。我们已经证明疫苗诱导的抗真菌CD8+T细胞持续存在 作为长期功能记忆。在这个方案中，我们提出了开创性的发现：1.GM-CSF+Tc17细胞支持 疫苗--无病理免疫；2.抗真菌CD8+T细胞优先表达O-糖基化 Sialophorin是CD8+T细胞分化和扩增所必需的。因此，我们的 中心假设是(1)Sialophorin作为CD8+T细胞反应的共刺激因子，(2)保留 Sialophorin对记忆CD8+T细胞稳态和回忆反应是必不可少的，(3)Sialophorin信号转导 增强交叉呈现以增强CD8+T细胞反应。我们的具体目标是：1.确定和 分析Sialophorin在CD8+T细胞真菌疫苗反应中的作用。我们将破译并描绘这个细胞- Sialophorin在疫苗过继转移和骨诱导的Tc17和Tc1细胞反应中的内在作用 骨髓嵌合体实验，并用TcRαKO、同源和杂交的Sialophorin KO小鼠。2.澄清 Sialophorin在真菌性肺炎期间记忆T细胞稳态和回忆反应中的作用。我们会 明确Sialophorin在疫苗诱导的记忆CD8+T细胞稳态、回忆反应和 疫苗免疫。我们将使用骨髓嵌合体，过继转移，CRISPR-Cas9基因编辑，体内 刺激和E-选择素阻断来描述Sialophorin在记忆CD8+T细胞反应中的作用。3. 分析Sialophorin在树突状细胞上对CD8+T细胞真菌疫苗反应的作用。 我们将确定 CD43在抗原提呈细胞激活免疫后CD8+T细胞中的作用 。我们的发现将 揭示Sialophorin对真菌CD8+T细胞反应和免疫的功能作用以指导设计 新型疫苗平台，并测试疫苗的效力。

PROJECT SUMMARY Despite the global rise in fungal infections, including those by endemic sp ., there is no licensed fungal vaccine available. This is mainly due to poor understanding of mechanisms of vaccine immunity, and lack of a functional phenotypic marker associated with vaccine efficacy. Opportunistic fungal infections, including those caused by dimorphic fungi, Histoplasma, Coccidiodes and Blastomyces, are rising at an alarming rate in such at-risk individuals. A major limitation in the development of tailored fungal vaccines for the at-risk population is poor understanding of requisite elements of CD8+ T cell responses to mediate vaccine-immunity. Recent advances in the understanding of immune correlates against fungal infections has helped in advancing vaccinology in parallel. T-cell derived IL-17A, IFNγ, GM-CSF, IL-22, and TNFα are primarily involved in protection against fungi. Identification of potential targets on host cells can provide novel efficacious vaccine platforms, including for immunocompromised. We have established a mouse model of CD4+ T cell lymphopenia, where CD8+ T cells can be stimulated to produce protective cytokines IL-17A (Tc17) and IFNγ (Tc1) to execute a sterilizing immunity against lethal pulmonary fungal infection. We have shown that vaccine-elicited antifungal CD8+ T cells persisted as long-term functional memory. In this proposal, we present seminal findings: 1. GM-CSF+ Tc17 cells bolster vaccine-immunity without pathology; 2. Anti-fungal CD8+ T cells preferentially express O-glycosylated Sialophorin; and 3. Sialophorin is required for differentiation and expansion of CD8+ T cells. Therefore, our central hypotheses are that (1) Sialophorin acts as a co-stimulator for CD8+ T cell responses, (2) retention of Sialophorin is essential for memory CD8+ T-cell homeostasis and recall responses, (3) Sialophorin signaling potentiates cross-presentation to augment CD8+ T cell responses. Our specific aims are to: 1. Determine and dissect the role of Sialophorin for CD8+ T-cell fungal vaccine responses. We will decipher and delineate the cell- intrinsic role of Sialophorin for vaccine-induced Tc17 and Tc1 cell responses using adoptive transfer and bone- marrow chimera experiments, and using TCRα KO, congenic and crosses of Sialophorin KO mice. 2. Elucidate the role of Sialophorin for memory T cell homeostasis and recall responses during fungal pneumonia. We will define the role of Sialophorin for vaccine-induced memory CD8+ T-cell homeostasis, recall responses, and vaccine-immunity. We will use bone marrow chimera, adoptive transfers, CRISPR-Cas9 gene-editing, in vivo stimulation, and E-selectin blocking to delineate the role of Sialophorin on memory CD8+ T-cell responses. 3. Dissect the role of Sialophorin on dendritic cells for CD8+ T-cell fungal vaccine responses. We will identify the role of CD43 on antigen-presenting cells for activation of CD8+ T cells following vaccination . Our findings will uncover the functional role of Sialophorin for fungal CD8+ T-cell responses and immunity to guide in the design of novel vaccine platforms and test the efficacy of vaccines.