Innate immune mechanisms of the host response to Coccidioides

摘要-项目1 项目1是一种新的合作方法，以了解先天免疫途径参与 宿主对球孢子虫的反应，这是一种侵袭性致病真菌，在美国每年导致20,000人感染。 只有1-2%的感染者会发展成一种严重且经常致命的形式，称为播散性 球菌病影响大脑、骨骼和/或皮肤，通常需要终生服用抗真菌药物 预防死亡和减少发病率的药物。决定感染患者病程的因素不是 已知，但很可能在许多此类患者中存在先天免疫失调，这是遗传的 下定决心。虽然我们已经了解了很多关于常见侵袭性真菌的正常宿主反应 病原菌如念珠菌和曲霉菌，对球孢子虫仍有许多需要了解的地方。 我们将采用多管齐下的方法，重点关注先天免疫反应的每一个主要步骤。 包括1)模式识别2)细胞因子反应和3)病原体处理 这种反应的分子水平，如RNA转录调节和串扰，蛋白质翻译和 翻译后处理，以及细胞功能和细胞与细胞的相互作用。为了实现我们的目标，我们有 在加州大学圣地亚哥分校建立了一个生物医学研究联盟，合作历史悠久，但相对较新 他是一位有40多年研究球虫经验的专家，对球孢子虫有共同的兴趣。 目的1.明确Dectin-1和抑制性Siglecs对人髓系细胞的调控机制 对球虫类药物的反应。使用来自正常人类捐赠者的髓系细胞，我们将描述人类如何 球虫的Dectin-1识别调控基因表达程序。使用功能增益研究，我们将 确定iSiglec参与如何抑制Dectin-1信号。最后，我们将决定人类如何 Dectin-1信号通路的多态性改变了对球虫的细胞免疫反应。 目的2.确定球虫感染和炎性小体中IL-1和IL-1的细胞来源 控制其加工和释放的依赖和独立途径 使用来自球菌患者和对照组的人血细胞或来自特定基因敲除小鼠的细胞进行挑战 用杀死的球孢子虫球体，我们将检查并阐明炎症体和非球虫的作用。 炎症小体介导的IL-1和IL-1在宿主对球虫感染的反应中的裂解和释放。 目的3.探讨激活和抑制受体在白细胞间穿梭中的作用 球孢子菌的内孢子。我们将研究通过激活和控制球孢子虫内孢子穿梭的方法 小鼠和人中性粒细胞、巨噬细胞和树突状细胞上的抑制受体。 这项工作的总体影响将提高我们对球虫免疫反应的理解 并提高我们预测球孢子菌病患者预后的能力。

Summary – Project 1 Project 1 is a new collaborative approach to understand the innate immune pathways involved in the host response to Coccidioides, an invasive pathogenic fungus resulting in 20,000 infections in the US annually. Only 1-2% of patients infected develop a severe and frequently lethal form, known as disseminated coccidiomycosis which affects brain, bones, and/or skin and usually requires lifelong therapy with anti-fungal drugs to prevent death and reduce morbidity. The factors determining the course of infected patients are not known, but it is likely that there is innate immune dysregulation in many of these patients that is genetically determined. While we have learned a great deal about the normal host response to common invasive fungal pathogens such as Candida and Aspergillus, there still remains much to be learned about Coccidioides. We will utilize a multi-pronged approach focusing on each major step of the innate immune response including 1) pattern recognition 2) cytokine responses and 3) pathogen processing, and on the specific molecular levels of this response such as RNA transcriptional regulation and cross-talk, protein translation and post-translation processing, as well as cell function and cell-cell interaction. To accomplish our goals, we have built a coalition of biomedical investigators at UCSD with a long history of collaboration, but a relatively new shared interest in Coccidioides and an expert with more than 40 years of experience studying Coccidioides. Aim 1. Define the mechanisms by which Dectin-1 and inhibitory Siglecs regulate human myeloid cell responses to coccidioides. Using myeloid cells from normal human donors we will characterize how human dectin-1 recognition of Coccidioides regulates gene expression programs. Using gain-of-function studies we will determine how iSiglec engagement inhibits Dectin-1 signaling. Finally, we will determine how human polymorphisms in Dectin-1 signaling pathways alter the cellular immune response to Coccidioides. Aim 2. Identify the cellular source of IL-1 and IL-1 in coccidioides infection and the inflammasome dependent and independent pathways controlling their processing and release Using human blood cells from cocci patients and controls or cells from specific knockout mice challenged with killed Coccidioides spherules, we will examine and shed light on the role of inflammasome and non- inflammasome mediated cleavage and release of IL-1 and IL-1 in the host response to Coccidioides infection. Aim 3. Investigate the contribution of activating and inhibitory receptors to inter-leukocyte shuttling of coccidioides endospores. We will investigate the control of Coccidioides endospore shuttling by activating and inhibitory receptors on mouse and human neutrophils, macrophages, and dendritic cells. The overall impact of this work will improve our understanding of the immune response to Coccidioides and improve our ability to predict outcomes in patients with coccidiomycosis.