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

CGAS-STING通路感应感染细胞和癌细胞中的胞浆DNA，并触发 I型干扰素和其他细胞因子，从而引发免疫反应。该途径的缺陷会阻止T 细胞对几种病毒和移植的肿瘤细胞的反应。我们的新结果表明，这条途径是 对于激活自发的NK细胞对癌症和病毒感染的反应至关重要。此外，在 通过对潜在机制的探索，我们的研究发现了一种新的细胞机制，即cGAS 刺痛会激活免疫反应。使用遗传方法，我们发现NK对 转移的肿瘤细胞依赖于肿瘤细胞中cGAS的表达和宿主细胞中的STIN表达。我们 解释这些数据以表明cGAS激活是发生在感染或转化细胞中的关键事件 从而产生环二核苷酸cGAMP。然后将cGAMP从 被感染/转化的细胞转化为其他免疫细胞，如抗原提呈细胞，被诱导启动 免疫反应。因此，我们认为cGAMP在细胞间的转移是一种基本的 免疫激活机制。在考虑cGAMP如何在细胞间转移时，我们假设 认为特定的膜转运蛋白必须发挥作用。使用全基因组CRISPRi筛查，我们发现了一种 特异性地将cGAMP导入细胞的转运蛋白分子。使用一系列的基因敲除小鼠 条件基因敲除小鼠，以及细胞操作和转移，我们建议测试 在NK和T细胞对癌症和DNA病毒的反应中的cGAS-STING信号，其共性 病毒感染和肿瘤模型对T细胞和NK细胞转移机制的要求 反应，新发现的转运蛋白在这个过程中的作用，并定义特定的细胞， 必须导入cGAMP才能产生免疫反应。具体地说，我们将：(1)确定 CGAMP及其STING和细胞间转移在包括NK在内的抗病毒反应中的作用 和T细胞反应；(2)确定cGAMP和刺激物的作用部位和细胞间转移 CGAMP在T细胞对癌症的反应中，在转移模型和GEM癌症模型中的作用；(3)确定 CGAMP转运体在抗病毒、抗肿瘤和免疫反应中的作用。使用条件性基因敲除小鼠 和抑制剂的研究，我们将测试它们在抗疱疹病毒和抗肿瘤反应中的功能，包括GEM 癌症的典范。

The cGAS-STING pathway senses cytosolic DNA in infected cells and cancer cells and triggers production of type I interferon and other cytokines, thus eliciting 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 a transporter molecule that specifically imports cGAMP into cells. 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, the roles of the newly identified transporters in the process, 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 of cancer.