STING-dependent activation of Natural Killer cells by viral and tumor DNA

cGAS-STING途径感测受感染细胞和癌细胞中的胞质DNA，并触发 I型干扰素和其他细胞因子，从而引发免疫反应。该途径的缺陷阻止T 细胞对几种病毒和移植肿瘤系的反应。我们的新结果表明， 对于激活针对癌症和病毒感染的自发NK细胞应答至关重要。更以 探索潜在的机制，我们的研究发现了一种新的细胞机制， 和STING激活免疫反应。使用遗传学方法，我们发现NK细胞对 转移的肿瘤细胞依赖于肿瘤细胞中的cGAS表达和宿主细胞中的STING表达。我们 解释这些数据以表明cGAS活化是发生在感染或转化细胞中的关键事件 从而产生环状二核苷酸cGAMP。然后将cGAMP从 感染/转化的细胞转化为其他免疫细胞，如抗原呈递细胞，其被诱导启动免疫应答。 免疫反应。因此，我们认为细胞之间的cGAMP转移是一个基本的 免疫激活机制。在考虑cGAMP如何在细胞之间转移时，我们假设 特定的膜转运蛋白必须发挥作用。使用全基因组CRISPRi筛选，我们发现了两个 一种特异性将cGAMP输入细胞的转运分子，其中一种起主要作用，另一种起主要作用， 次要角色使用一系列基因敲除小鼠和条件性基因敲除小鼠，以及细胞操作和 转移，我们建议测试cGAS-STING信号传导在NK和T细胞对癌症的应答中的需求。 和DNA病毒，在病毒感染和癌症的转移机制的要求的一般性 模型和T细胞和NK细胞应答，包括新鉴定的转运蛋白的作用，以及 定义必须输入cGAMP以发生免疫应答的特定细胞。具体而言，我们将： (1)确定cGAMP和STING的作用位点以及cGAMP在抗病毒药物中的细胞间转移 （2）确定cGAMP和STING的作用位点， 在转移模型和GEM癌症模型中，在对癌症的T细胞应答中cGAMP的细胞间转移; (3)确定cGAMP转运蛋白在抗病毒、抗肿瘤和免疫应答中的作用。使用 条件性基因敲除小鼠和抑制剂研究，我们将测试它们在抗疱疹病毒和抗肿瘤方面的功能 包括GEM模型。

The cGAS-STING pathway senses cytosolic DNA in infected cells and cancer cells and triggers production of type I interferon and other cytokines, thus triggering immune responses. Deficiency in the pathway prevents T cell responses to several viruses and to transplanted tumor lines. Our new results show that the pathway is critical for activating spontaneous NK cell responses against cancer and virus infections. Furthermore, in probing the underlying mechanisms, our research has uncovered a new cellular mechanism whereby cGAS and STING activate immune responses. Using genetic approaches, we found that the NK response to transferred tumor cells depends on cGAS expression in tumor cells and STING expression in host cells. We interpret these data to indicate that cGAS activation is the key event that occurs in infected or transformed cells resulting in the production of the cyclic dinucleotide cGAMP. cGAMP is then transferred from the infected/transformed cells to other immune cells, such as antigen presenting cells, which are induced to initiate the immune response. Hence, we propose that cGAMP transfer between cells is a fundamental mechanism in immune activation. In considering how cGAMP is transferred between cells, we hypothesized that specific membrane transporters must play a role. Using a genome-wide CRISPRi screen, we identified two transporter molecules that specifically import cGAMP into cells, one of which plays a major role and other a minor role. Using a series of knockout mice and conditional knockout mice, and cellular manipulations and transfers, we propose to test the requirement of cGAS-STING signaling in NK and T cell responses to cancer and DNA viruses, the generality of the requirement of the transfer mechanism in viral infections and cancer models and for T cell and NK cell responses, including the roles of the newly identified transporters, and to define the specific cells that must import the cGAMP for immune responses to occur. Specifically, we will: (1) Determine the sites of action of cGAMP and STING and intercellular transfer of cGAMP in anti-viral responses, including NK and T cell responses; (2) Determine sites of action of cGAMP and STING and intercellular transfer of cGAMP in T cell responses to cancer, in transfer models and GEM cancer models; (3) Determine roles of cGAMP transporters in anti-viral and anti-tumor and immune responses. Using conditional knockout mice and inhibitor studies, we will test their function in anti-herpesvirus and anti-tumor responses, including a GEM model.