Immune activation by necroptotic cell death

程序性细胞死亡是正常发育和组织稳态所必需的，但也可以作为一种细胞凋亡而发生。 对病原体感染的防御反应我们现在知道细胞可以经历不同形式的 程序性细胞死亡：除了细胞凋亡之外，坏死性凋亡是最近描述的细胞自杀形式， 可由病毒感染引起。坏死涉及细胞肿胀和破裂， 假设在体内发生时触发炎症和免疫反应，但 对坏死性凋亡的免疫应答还不清楚。我们发现激活这个关键 坏死性凋亡诱导激酶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激活诱导的趋化因子表达， 伴随RIPK3诱导的细胞死亡，并且这种转录反应是导致坏死性凋亡所必需的。 免疫原性。这就引出了这一提议的中心假设：坏死性凋亡代表了一种独特的 免疫原性形式的细胞死亡，因为它结合的生产，如果免疫吸引趋化因子 溶解性细胞死亡我们将检验这一观点的一个重要延伸，即诱导坏死性凋亡 在肿瘤微环境中的作用将促进有益的肿瘤免疫。为了验证这个想法，我们将 专注于三个目标。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、呈递和反应来自凋亡、坏死性凋亡或坏死细胞的抗原。 然后，我们将使用侧腹肿瘤模型，结合新开发的快速诱导 不同形式的体内细胞死亡，评估对肿瘤细胞坏死性死亡的免疫应答。我们 将这些发现应用于临床相关的肿瘤模型，通过测试免疫信号的能力， 通过肿瘤细胞坏死凋亡产生，与免疫检查点抑制剂协同作用， 清除转移病灶。最后，我们将创建和测试一个系统，允许快速诱导坏死性凋亡 在体内未修饰的肿瘤细胞中。总之，这里提出的实验将确定是什么使 坏死性凋亡免疫原性，然后将这些发现应用于肿瘤免疫治疗的模型。

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.