Novel mechanism of induction of tumor pyroptosis by IL-9-secreting Tc9 cells

项目摘要 血液CD8 + T细胞可以基于其细胞因子截面谱被细分为不同的亚群， 功能协调发展的我们已经证明，分泌IL-9的CD8 + Tc9细胞在体内介导更强的抗肿瘤作用， 与经典的分泌IFN-γ的Tc1或CTL相比。然而，其潜在机制仍不清楚。 最近，我们发现，Tc9细胞可以通过诱导增强的免疫抑制来根除大型肿瘤。 肿瘤焦亡，一种依赖于半胱天冬酶-1激活的程序性细胞死亡形式。我们的初步研究 结果显示，Tc9细胞处理的肿瘤具有IL-1 β和IL-18的表达增加以及活化的caspase-1， 和更多的肿瘤细胞死亡。体内完全中和IL-1 β和IL-18 消除了Tc9细胞在肿瘤对照中相对于Tc1细胞的治疗优势。我们进一步表明， 肿瘤特异性Tc9细胞通过诱导caspase-1依赖的细胞凋亡和caspase-3依赖的细胞凋亡来杀伤肿瘤细胞。 Tc1细胞主要诱导肿瘤细胞凋亡。类似地，人肿瘤特异性 与Tc1细胞相比，Tc9细胞在体内也显示出更强的抗肿瘤作用，其是IL-1 β-和IL-18-。 依赖。有趣的是，我们观察到IL-1 β + IL-18在培养的Tc1细胞中诱导凋亡，但在Tc9细胞中不诱导凋亡， Tc9细胞衍生的IL-9对于Tc9细胞活化STAT3以及促生长和存活信号传导是关键的， IL-1 β和IL-18可以重新激活老化Tc9细胞中的STAT3和促生长和存活信号 减少IL-9的产生。因此，这些发现揭示了Tc9细胞 克服转移后抑制性肿瘤微环境，存活和持续时间更长，并发挥 与传统的Tc1细胞相比，具有更高的抗肿瘤活性。我们假设肿瘤特异性Tc9 亚群可能是用于癌症免疫治疗极好的效应T细胞，因为它们能够诱导 肿瘤细胞中的细胞凋亡和细胞凋亡，并利用Tc9细胞分泌的IL-9和肿瘤产生的IL-1 β和IL-18 因为它们的适应性、寿命和在体内有效根除大的已建立肿瘤的功能。来测试我们 目的1将确定Tc9细胞诱导的肿瘤细胞热凋亡在肿瘤细胞凋亡中的重要性和机制。 通过IL-9和GrzB诱导的NF-κ B-NLRP 3-caspase-1-gasdermin活化来清除肿瘤，而Aim 2将 确定Tc9细胞持久性和由Tc9细胞介导的功能的作用和机制， 分泌的IL-9和肿瘤产生的IL-1 β和IL-18。完成这个项目将揭示的重要性， 肿瘤特异性Tc9细胞诱导肿瘤细胞凋亡的机制， 这是Tc9细胞在肿瘤微环境中的寿命和功能的基础。

PROJECT SUMMARY Blood CD8+ T cells can be subdivided into different subsets based on their cytokine section profiles and functions. We have shown that IL-9-secreting CD8+ Tc9 cells mediate a stronger antitumor effect in vivo compared to the classical IFN--secreting Tc1 or CTLs. However, the underlying mechanisms remain unclear. Recently, we discovered that Tc9 cells could eradicate large-established tumors by inducing an enhanced tumor pyroptosis, a form of programmed cell death dependent on caspase-1 activation. Our preliminary studies showed that Tc9 cell-treated tumors had increased expressions of IL-1 and IL-18 and activated caspase-1, and more tumor cell death compared to Tc1-treated tumors. Neutralizing IL-1 and IL-18 in vivo completely abrogated the therapeutic advantage of Tc9 cells over Tc1 cells in tumor controls. We further showed that tumor-specific Tc9 cells killed tumor cells by inducing both caspase-1-depedent pyroptosis and caspase-3- dependent apoptosis while Tc1 cells mainly induced apoptosis in tumor cells. Similarly, human tumor-specific Tc9 cells also displayed stronger antitumor effects in vivo compared to Tc1 cells, which was IL-1- and IL-18- dependent. Interestingly, we observed that IL-1 plus IL-18 induced apoptosis in cultured Tc1 but not Tc9 cells, Tc9 cell-derived IL-9 is critical for Tc9 cell activation of STAT3 and pro-growth and survival signaling and function, and IL-1 plus IL-18 can re-activate STAT3 and pro-growth and survival signaling in aged Tc9 cells with reduced IL-9 production. Thus, these findings reveal novel mechanisms underlying how Tc9 cells overcome the suppressive tumor microenvironment after transfer, survive and persist longer, and exert a greater antitumor activity as compared to the traditional Tc1 cells. We hypothesize that tumor-specific Tc9 subset may be superb effector T cells for cancer immunotherapy due to their capacity to induce both pyroptosis and apoptosis in tumor cells and utilize Tc9 cell-secreted IL-9 and tumor-produced IL-1 and IL-18 for their fitness, longevity, and function in vivo to effectively eradicate large established tumors. To test our hypothesis, Aim 1 will determine the importance and mechanisms of Tc9 cell-induced tumor cell pyroptosis in tumor clearance via IL-9- and GrzB-induced NFB-NLRP3-caspase-1-gasdermin activation, and Aim 2 will determine the role and mechanisms underlying Tc9 cell persistence and function mediated by Tc9 cell- secreted IL-9 and tumor-produced IL-1 and IL-18. Completing this project will reveal the importance and mechanism in induction of tumor pyroptosis by tumor-specific Tc9 cells and elucidate the mechanisms underlying the longevity and function of Tc9 cells in tumor microenvironment.