MECHANISMS OF SIGNALING BY ACTIVATING RECEPTORS IN INNATE IMMUNE SYSTEMS CELLS

本提案是根据2009年美国复苏和再投资法案no - od -09-088号通知提出的。我们要求为修订后的资助申请1R01AI73718-01A2的前两年提供资金，范围的变化由NIAID项目官员批准。具体而言，我们建议阐明DAP10/DAP12/ fcr相关激活受体（DAPAARs）的信号传导分子机制，如NK细胞中的NKG2D和髓细胞中的整合素，并确定编码介导DAPAARs发出的信号所必需的蛋白质的几个基因在微生物发病过程中作为敏感位点的作用。在这种背景下，我们最近发现了Vav和DAP10/DAP12/FcR蛋白在NK细胞和髓细胞中介导先天免疫受体（包括激活受体）的信号传导中的关键新功能。基于这些初步数据，我们提出了一个模型，其中Vav和磷酸肌肽3-激酶（PI3K）参与串扰，放大导致NK细胞毒性的信号。Vav蛋白通过激活ITAM依赖性和非ITAM依赖性信号来控制先天免疫反应的概念代表了信号转导和细胞激活的新范式。在这种背景下，包括我们在内的几个实验室的惊人新发现揭示了一个以前未预料到的机制，在这个机制中，整合素和其他粘附受体利用DAP12和FcR来促进粘附和效应反应。虽然中性粒细胞效应反应的增强，包括细胞因子的产生、脱颗粒和通过粘附整合素配体的吞噬，已经被认识了30多年，这些新的结果揭示了促炎刺激和粘附受体激活的共享信号模块。在这个修改后的提议中，我们旨在建立nkg2ddap10 -近端信号和Vav1-PI3K串扰的机制（aim 1），描绘DAP10/DAP12/ fcr相关激活受体（DAP-AARs）发出的信号通路，并确定几个编码介导DAP-AARs发出的信号必需蛋白的基因在体内微生物发病中的作用（aim 2）。

This proposal is in response to Notice Number NOT-OD-09-088 of the American Recovery and Reinvestment Act of 2009. We request funding for the first two years of the revised grant application 1R01AI73718-01A2, with changes in scope approved by the NIAID Program Officer. Specifically, we propose to elucidate the molecular mechanism of signaling by DAP10/DAP12/FcR-associated activating receptors (DAPAARs), such as NKG2D in NK cells and integrins in myeloid cells, and to establish the role for several genes encoding proteins essential for mediating signals emanating from DAP-AARs as susceptibility loci in microbial pathogenesis. In this context, we have recently identified critical new functions of Vav and DAP10/DAP12/FcR proteins in transducing signals emanating from innate immune receptors including activating receptors in NK cells and myeloid cells. Based on these preliminary data, we propose a model in which Vav and Phosphoinositide 3-kinase (PI3K) engage in crosstalk to amplify signals leading to NK cytotoxicity. The concept that Vav proteins control innate immune responses by activating both ITAM- and non-ITAM-dependent signaling represents a novel paradigm in signal transduction and cellular activation. In this context, striking new findings from several labs including ours reveal a previously unanticipated mechanism in which integrins and other adhesion receptors utilize DAP12 and FcR to promote both adhesion and effector responses. While the augmentation of neutrophil effector responses including cytokine production, degranulation, and phagocytosis by adherence to integrin ligands has been appreciated for over 30 years, these new results reveal shared signaling modules activated by both proinflammatory stimuli and adhesion receptors. In this modified proposal, we aim to establish the mechanism of NKG2DDAP10-proximal signaling and Vav1-PI3K crosstalk (Aim 1), and to delineate signaling pathways emanating from the DAP10/DAP12/FcR-associated activating receptors (DAP-AARs) and establish the role for several genes encoding proteins essential for mediating signals emanating from DAP-AARs as susceptibility loci in microbial pathogenesis in vivo (Aim 2).