Characterizing Macrophages as "Hide-Outs" for Chronic Pathogens

项目摘要 该提案描述了Kiera克莱顿博士的NIAID新创新者DP2奖的框架。博士 克莱顿目前是一个博士后研究员的监督下，布鲁斯步行者博士在拉根研究所， MGH，MIT和哈佛，他们目前的研究重点是T细胞和NK细胞介导的对HIV感染者的杀伤。 巨噬细胞，以及对HIV储库持久性和巨噬细胞介导的炎症的影响。在 除了克莱顿博士发表的工作表明巨噬细胞对T细胞介导的杀伤具有抗性外， 该提案中的初步结果表明，HIV利用巨噬细胞逃避NK细胞介导的 杀伤，通过与用于逃避T细胞应答的机制不同的机制。由于巨噬细胞也充当 其他慢性病原体的主要细胞储存库，包括结核分枝杆菌（Mtb）， 巨噬细胞是否为免疫逃避提供了一个共同的"隐藏"仍然存在。因此，这一总体目标 一项建议是描述不同慢性病原体感染巨噬细胞的机制 以逃避免疫介导的清除，并探索靶向常见免疫逃避的可能性。 途径增强T细胞和NK细胞对感染巨噬细胞的杀伤。本研究重点关注三个方面的研究。 地区第一个研究领域将建立在初步数据的基础上，以确定艾滋病毒感染者 巨噬细胞阻止NK细胞介导的杀伤。为了定量Mtb感染的巨噬细胞对 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和抗原特异性 T细胞和NK细胞。最后，正如克莱顿博士发表的研究表明， 由于对诱导凋亡的T细胞来源的颗粒酶的抗性，第三个研究领域将探索 鉴定由巨噬细胞表达的颗粒酶抑制剂，随后敲除候选基因， 增强T和NK细胞介导的对受感染巨噬细胞的杀伤。总之，这些研究将提供洞察力， 研究是否靶向天然颗粒酶抑制剂可以提供一种增强免疫介导的 清除不同病原体感染的巨噬细胞。本提案的目标与 NIAID的使命，并将提高我们对不同病原体特异性免疫逃避机制的理解 以及巨噬细胞的固有特征，尽管免疫力很强， 应答最终，这项工作将有助于设计和开发针对艾滋病毒和结核病的治疗方法。 感染的巨噬细胞，并将加强未来的研究，以评估如何巨噬细胞介导的 免疫逃避有助于其他病原体的持续存在，包括人巨细胞病毒。

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.