Immune activation by necroptotic cell death

程序性细胞死亡是正常发育和组织动态平衡所必需的，但也可以作为一种 对病原体感染的防御性反应。我们现在了解到，细胞可以经历不同形式的 细胞程序性死亡：除细胞凋亡外，坏死性下垂是最近被描述的一种细胞自杀形式， 可由病毒感染引起。坏死性下垂涉及细胞肿胀和破裂，一直以来 假设当它在体内发生时会触发炎症和免疫反应，但 对坏死性下垂的免疫反应还不是很清楚。我们发现密钥的激活 坏死下垂诱导激酶，RIPK3，除了诱导细胞死亡外，还可以触发转录反应。 此外，我们的初步数据表明，RIPK3激活诱导趋化因子的表达 伴随着RIPK3诱导的细胞死亡，并且这种转录反应是导致坏死性下垂所必需的 免疫原性。这就引出了这一提议的中心假设：坏死性下垂代表着一种独特的 细胞死亡的免疫原性形式，因为它结合了免疫吸引趋化因子的产生 伴随着溶细胞死亡。这一想法的一个重要扩展，我们将进行测试，是诱导坏死性下垂 在肿瘤微环境内，会促进有益的肿瘤免疫。为了测试这一想法，我们将 聚焦三个目标。首先，我们将使用新的高内容成像方法来比较 免疫系统运输、呈递和反应来自于凋亡、坏死性或坏死性细胞的抗原。 然后，我们将使用侧翼肿瘤模型，结合新开发的系统快速诱导 体内不同形式的细胞死亡，评估肿瘤细胞坏死性死亡的免疫反应。我们 将通过测试免疫信号的能力，将这些发现应用于临床相关的肿瘤模型 由肿瘤细胞坏死下垂产生，与免疫检查点抑制剂协同作用，促进免疫 转移灶的清除。最后，我们将创建并测试一个可以快速诱导坏死性下垂的系统 在体内未修饰的肿瘤细胞中。总之，这里提出的实验将决定是什么 然后将这些发现应用到肿瘤免疫治疗的模型中。

Programmed cell death is required for normal development and tissue homeostasis, but can also occur as a defensive response to pathogen infection. We now understand that cells can undergo distinct forms of programmed cell death: in addition to apoptosis, necroptosis is a recently-described form of cell suicide that can be induced by viral infection. Necroptosis involves cellular swelling and rupture, and has been hypothesized to trigger inflammatory and immune responses when it occurs in vivo, but the determinants of immune responses to necroptosis are not well understood. We have found that activation of the key necroptosis-inducing kinase, RIPK3, can trigger transcriptional responses in addition to inducing cell death. Furthermore, our preliminary data indicate that chemokine expression induced by RIPK3 activation accompanies RIPK3-induced cell death, and that this transcriptional response is required to render necroptosis immunogenic. This leads to the central hypothesis of this proposal: That necroptosis represents a uniquely immunogenic form of cell death, because it couples the production if immune-attractant chemokines with lytic cell death. An important extension of this idea, which we will test, is that induction of necroptosis within the tumor microenvironment will promote beneficial tumor immunity. To test this idea, we will focus on three Aims. First, we will use novel high-content imaging approaches to compare the way the immune system traffics, presents, and reacts to antigens derived from apoptotic, necroptotic, or necrotic cells. We will then use flank tumor models, in combination with a newly developed system for the rapid induction of different forms of cell death in vivo, assess the immune response to the necroptotic death of tumor cells. We will apply these findings to clinically-relevant tumor models, by testing the ability of the immune signature created by tumor cell necroptosis to synergize with immune checkpoint inhibitors and to promote immune clearance of metastatic lesions. Finally, we will create and test a system allowing rapid induction of necroptosis in unmodified tumor cells in vivo. Together, the experiments proposed here will determine what makes necroptosis immunogenic, then apply these findings to models of tumor immunotherapy.