Characterizing Macrophages as "Hide-Outs" for Chronic Pathogens

项目总结 本提案描述了NIAID为Kiera Clayton博士颁发的新创新者DP2奖的框架。Dr。 克莱顿目前是拉贡研究所布鲁斯·沃克博士指导下的博士后研究员。 麻省理工学院和哈佛大学，他们目前的研究重点是T细胞和NK细胞介导的艾滋病毒感染的杀伤 巨噬细胞，以及对艾滋病毒储存库持久性和巨噬细胞介导的炎症的影响。在……里面 除了克莱顿博士发表的表明巨噬细胞对T细胞介导的杀伤具有抵抗力的工作外， 这项提案中包含的初步结果表明，艾滋病毒利用巨噬细胞来逃避NK细胞介导的 通过与用于逃避T细胞反应的机制不同的机制进行杀戮。因为巨噬细胞也扮演着 其他慢性病原体的主要细胞储存库，包括结核分枝杆菌(Mtb)，这个问题 巨噬细胞是否为免疫逃避提供了共同的“藏身之处”。因此，这一计划的总体目标是 建议描述不同慢性病原体感染的巨噬细胞所使用的机制。 逃避免疫介导的清除，并探索以共同的免疫逃避为目标的可能性 增强感染巨噬细胞T细胞和NK细胞杀伤作用的途径。这项建议侧重于三项研究 区域。第一个研究领域将以初步数据为基础，以确定艾滋病毒感染的机制 巨噬细胞可防止NK细胞介导的杀伤。定量检测结核分枝杆菌感染巨噬细胞对结核分枝杆菌的抵抗力 T细胞和NK细胞介导的消除并表征伴随的免疫逃避机制， 第二个研究领域将描述结核分枝杆菌感染的巨噬细胞与抗原特异性之间的相互作用 T细胞和NK细胞。最后，正如克莱顿博士发表的研究表明，对巨噬细胞的低效杀伤是 由于抵抗诱导凋亡的T细胞衍生颗粒酶，第三研究领域将探索 巨噬细胞表达的颗粒酶抑制物以及随后敲除的候选基因的鉴定 增强T和NK细胞对感染巨噬细胞的杀伤作用。总之，这些研究将提供洞察力 靶向天然颗粒酶抑制剂是否可以提供一种通用的方法来增强免疫介导性 不同病原体感染的巨噬细胞的清除。这项提案的目标与 NIAID的使命，并将增强我们对不同病原体特异性免疫逃避机制的理解 巨噬细胞的固有特征是，尽管免疫能力很强，但病原体仍能持续存在 回应。最终，这项工作将有助于针对艾滋病毒和结核分枝杆菌的治疗药物的设计和开发。 巨噬细胞中的感染，并将加强未来的研究，以评估巨噬细胞如何介导 免疫逃避有助于其他病原体的持续存在，包括人类巨细胞病毒。

PROJECT SUMMARY This proposal describes the framework of an NIAID New Innovators DP2 award for Kiera Clayton, PhD. Dr. Clayton is currently a postdoctoral fellow under the supervision of Dr. Bruce Walker at the Ragon Institute of MGH, MIT and Harvard, whose current research focuses on T cell and NK cell-mediated killing of HIV-infected macrophages, and the implications for HIV reservoir persistence and macrophage-mediated inflammation. In addition to Dr. Clayton’s published work suggesting that macrophages are resistant to T cell-mediated killing, preliminary results included in this proposal suggest that HIV exploits macrophages to evade NK cell-mediated killing, by mechanisms distinct from those used to evade T cell responses. As macrophages also act as the primary cellular reservoir for other chronic pathogens, including Mycobacterium tuberculosis (Mtb), the question remains whether macrophages provide a common “Hide-Out” for immunoevasion. Thus, the overall goal of this proposal is to characterize the mechanisms employed by macrophages infected by different chronic pathogens to evade immune-mediated clearance and explore the possibility of targeting a common immunoevasion pathway to enhance T cell and NK cell killing of infected macrophages. This proposal focuses on three Research Areas. The first Research Area will build on preliminary data to define the mechanisms by which HIV-infected macrophages prevent NK cell-mediated killing. To quantify the resistance of macrophages infected with Mtb to T cell and NK cell-mediated elimination and characterize the accompanying immunoevasion mechanisms, the second Research Area will characterize the interactions between Mtb-infected macrophage and antigen-specific T cells and NK cells. Finally, as Dr. Clayton’s published work suggests that inefficient killing of macrophages is a result of resistance to apoptosis-inducing T cell-derived granzymes, the third Research Area will probe for the identities of granzyme inhibitors expressed by macrophages, and subsequently knockout candidate genes to enhance T and NK cell-mediated killing of infected macrophages. Together, these studies will provide insight into whether targeting natural granzyme inhibitors can provide a common method to enhance immune-mediated clearance of macrophages infected by different pathogens. The goals of this proposal are highly relevant to the mission of NIAID, and will enhance our understanding of distinct pathogen-specific immunoevasion mechanisms and those inherently characteristic of macrophages that allow for pathogen persistence despite strong immune responses. Ultimately, this work will aid the design and development of therapeutics to target HIV and Mtb infection in macrophages, and will potentiate future studies to assess how macrophage-mediated immunoevasion contributes to persistence of other pathogens, including human cytomegalovirus.