Rescuing Anti-tumor Responses of TCR-Td T Cells by NKG2D-stimulation

表达肿瘤抗原反应的T细胞受体基因修饰T细胞的过继细胞转移 (TCR-TD T细胞)已成为治疗恶性肿瘤最有前途的方法之一。 然而，最近的临床研究报告客观的临床缓解率低于30%。提供了一个看似合理的 对这些反应的解释是，研究表明，在荷瘤宿主中，转移的T细胞遇到 以免疫抑制为特征的不适宜居住的环境。因此，渲染TCR-TD CD8+T细胞 抵抗这些负面的环境线索可以显著改善癌症患者的临床反应。 考虑到NKG2D受体的刺激作用，我们研究了它控制CD8+T细胞的能力 压制。我们的数据首次显示，NKG2D刺激人TCR-TD CD8+T细胞(类似于 和小鼠CD8+T细胞导致对转化生长因子-β抑制的完全抵抗 并增强对黑色素瘤的治疗抗肿瘤反应。我们的数据还显示，NKG2D激活 TCR-TD CD8+T细胞对转化生长因子-β抑制的抵抗伴随着两种阴性表达的上调 转化生长因子β信号、RGS3和PDPK1的调节因子。虽然这些发现描绘了NKG2D在体内的新功能 CD8+T细胞在NKG2D信号通路和抵抗抑制中的相互作用 仍有待确定。我们推测NKG2D诱导TCR-TD CD8+T细胞对 抑制是通过PI3K、Grb2和JNK通路以及RGS3和PDPK1的联合作用来实现的。 因此，本提案的目的是剖析NKG2D利用的近端和远端信号通路 增强对转化生长因子β的抵抗力和抗肿瘤免疫能力。为了做到这一点，我们将使用人和老鼠 转导CD8+T细胞表达针对酪氨酸酶多肽/人类白细胞抗原A2和H3T转基因小鼠的TCR， 它们表达相同的受体。我们的研究假设了一种新的范式；人类CD8+T细胞可以 转录上受NKG2D信号调控，实现对转化生长因子β的抗性。我们相信人类 TCR-TD CD8+T细胞在ACT前可以很容易地被NKG2D激动剂调节以提高其存活率 和治疗抗肿瘤的能力。

Adoptive cell transfer of T cells genetically modified to express a T cell receptor reactive to a tumor antigen (TCR-Td T cells) has emerged as one of the most promising approaches for the treatment of malignancies. However, recent clinical studies report objective clinical response rates lower than 30%. Providing a plausible explanation for these responses, studies have shown that, in tumor-bearing hosts, transferred T cells encounter an inhospitable environment characterized by immune suppression. Hence, rendering TCR-Td CD8+ T cells resistant to these negative environmental cues could significantly improve clinical responses in cancer patients. Given the stimulatory role of the NKG2D receptor, we investigated its ability to control CD8+ T cell suppression. Our data show for the first time that NKG2D stimulation in human TCR-Td CD8+ T cells (similar to those used in clinical trials) and mouse CD8+ T cells results in complete resistance to suppression by TGF-¿ and augmented therapeutic anti-tumor responses against melanoma. Our data also show that NKG2D-activated TCR-Td CD8+ T cell resistance to suppression by TGF-¿ is accompanied by the upregulation of two negative regulators of TGF-¿ signaling, RGS3 and PDPK1. While these findings depict novel functions for NKG2D in CD8+ T cells, how these pathways are interconnected in NKG2D signaling and resistance to suppression remains to be determined. We hypothesize that NKG2D-induced resistance of TCR-Td CD8+ T cells to suppression is mediated by the PI3K, Grb2, and JNK pathways and the combined effects of RGS3 and PDPK1. Thus, the objective of this proposal is to dissect the proximal and distal signaling pathways utilized by NKG2D to confer resistance to TGF-¿ and enhanced anti-tumor immunity. To do this, we will use human and mouse CD8+ T cells transduced to express a TCR against a tyrosinase peptide/HLA-A2 and h3T transgenic mice, which express the same receptor. Our study posits a new paradigm; human CD8+ T cells can be transcriptionally manipulated by NKG2D signaling to achieve resistance to TGF-¿. We believe that human TCR-Td CD8+ T cells could be easily conditioned prior to ACT by an NKG2D agonist to enhance their survival and therapeutic anti-tumor capacity.