Dissecting the tumor-intrinsic and -extrinsic roles of TBK1 in tumor immunity

项目摘要 针对PD-1/PD-L1通路的免疫检查点阻断(ICB)已引起戏剧性和持久性的临床 黑色素瘤和其他癌症的反应。尽管ICB取得成功，但有效的治疗策略 克服对癌症免疫疗法的抵抗力不足。坦克结合蛋白1(Tak1)是一种多功能的先天蛋白 免疫蛋白激酶作为候选免疫逃逸基因在一些集合遗传筛查中被提名。 使用多个实验模型系统的遗传学和药理学工具，我们已经确认了一个角色 TANK-BINDING KEK1(TBK1)作为免疫逃避基因。靶向TBK1通过以下方式增强对ICB的响应 降低对免疫细胞分泌的效应细胞因子(TNFa/IFNG)的细胞毒阈值。肿瘤细胞 缺乏TBK1的细胞准备经历RIPK1依赖的细胞死亡，以回应TNFa/IFNG。超越它的影响 在癌细胞中，针对免疫细胞中的TBK1似乎通过抑制TBK1/-PD-1来增强这一效应 阻断不仅促进效应/祖细胞衰竭的CD8T细胞和M1样细胞的积聚 巨噬细胞，但足以增加炎症细胞因子(如，IFNG，TNFa)的产生 细胞。综上所述，我们的结果表明，靶向TBK1是一种新颖而有效的策略来克服 对肿瘤免疫治疗的抵抗力，并提出关于肿瘤细胞中TBK1功能的重要问题 与免疫细胞在肿瘤免疫中的对比。在这项提案中，我们的目标是确认和扩大这些初步观察结果 并解析了TBK1在肿瘤免疫中的细胞类型特异性作用。 在目标1中，我们将确定tbk1在抗癌中的癌细胞特异性作用和调控。 免疫治疗，通过在ICB耐药性的背景下定义TBK1的下游底物并定义 上游调控机制(S)促进免疫逃避。 在目标2中，我们通过检测条件性T细胞因子的作用来确定TBK1在抗肿瘤免疫中的T细胞特异性作用。 CD8T细胞中TBK1基因缺失。我们将使用CD8T细胞特异性的TBK1条件性基因敲除小鼠模型来 明确T细胞中TBK1缺失对ICB疗效和肿瘤浸润性免疫细胞分布的影响， CD8T细胞效应器功能/功能障碍。 在目标3中，我们将剖析TBK1在调节肿瘤内髓系细胞中的作用。使用髓系特异性的TBK1 条件基因敲除小鼠模型，我们将确定髓系特异性TBK1缺失对疗效的影响 ICB和肿瘤浸润性免疫细胞的景观，以及巨噬细胞和 其他髓系细胞群。

Project Summary Immune checkpoint blockade (ICB) targeting the PD-1/PD-L1 pathway has induced dramatic and durable clinical responses in melanoma and other cancers. Despite the success of ICB, effective treatment strategies to overcome resistance to cancer immunotherapy are lacking. TANK-binding kinase 1 (TBK1) is a versatile innate immune protein kinase nominated as a candidate immune evasion gene in a number of pooled genetic screens. Using genetic and pharmacologic tools across multiple experimental model systems, we have confirmed a role for TANK-binding kinase 1 (TBK1) as an immune evasion gene. Targeting TBK1 enhances response to ICB by lowering the cytotoxicity threshold to effector cytokines (TNFa/IFNg) secreted by immune cells. Tumor cells lacking TBK1 are primed to undergo RIPK1-dependent cell death in response to TNFa/IFNg. Beyond its effect on cancer cells, targeting TBK1 in immune cells appears to augment this effect as TBK1 inhibition +/- PD-1 blockade not only promoted accumulation of effector/progenitor exhausted CD8 T cells and M1-like macrophages, but was sufficient to enhance production of inflammatory cytokines (e.g., IFNg, TNFa) from these cells. Taken together, our results demonstrate that targeting TBK1 is a novel and effective strategy to overcome resistance to cancer immunotherapy and raise important questions about the function of TBK1 in cancer cells versus immune cells in tumor immunity. In this proposal, we aim to confirm and extend these initial observations and resolve the cell type specific roles of TBK1 in tumor immunity. In Aim 1, we will determine the cancer cell-specific roles and regulation of TBK1 in resistance to cancer immunotherapy, by defining the downstream substrates of TBK1 in the setting of ICB resistance and defining upstream the mechanism(s) of TBK1 regulation promoting immune evasion. In Aim 2, we define the T cell-specific role of TBK1 in anti-tumor immunity by examining the effect of conditional deletion of TBK1 in CD8+ T cells. We will use CD8+ T cell specific TBK1 conditional knockout mouse models to define the effect of TBK1 deletion in T cells on the efficacy of ICB and profile of tumor-infiltrating immune cells, and CD8+ T cell effector function/dysfunction. In Aim 3, we will dissect the role of TBK1 in regulating intratumoral myeloid cells. Using myeloid-specific TBK1 conditional knockout mouse models, we will define the effect of myeloid-specific TBK1 deletion on the efficacy of ICB and the landscape of tumor infiltrating immune cells, as well as the effector function of macrophages and other myeloid cell populations.