CD4+ T cells and neoantigens in melanoma immunotherapy.

项目摘要 最近的临床试验，使用检查点阻断、抗原特异性T细胞受体（TCR）或CD 19嵌合抗原 受体（CAR）的研究已经显示出对转移性癌症患者有希望的临床结果。但尽管 在用抗PD-1抗体治疗的癌症患者中，超过50%的 癌症患者对这种检查点阻断治疗没有反应。基于疫苗的免疫治疗， 由于缺乏肿瘤特异性靶点，许多实体瘤中的TCR仍然缺乏。因此，新的目标和 迫切需要发展用于实体瘤的免疫方法的策略， 黑素瘤结合计算机辅助预测算法的全外显子组测序方法 为确定新的癌症患者特异性抗原靶点提供了一个难得的机会 免疫疗法通过利用下一代测序和肿瘤反应性T细胞，我们最近 鉴定了许多被肿瘤反应性CD 4 + T细胞以及CD 8 + T细胞识别的新抗原。重要的是我们 发现一些具有单一TCR的CD 4 + T克隆可以识别多种新抗原，但不能识别CD 4 + T克隆。 相应的野生型抗原。最近的临床研究表明，突变特异性CD 4 + T细胞可以介导 黑色素瘤和上皮癌中的肿瘤生长抑制，表明CD 4 + T细胞在 抑制肿瘤生长并协调整体抗肿瘤免疫。然而，癌症的临床反应 患者与T细胞的运输、持久性和细胞毒能力相关。我们发现，CD 4 + T细胞 可以被重新编程以增加它们对癌细胞的细胞毒性活性。基于这些前提，我们 假设新抗原特异性T细胞，特别是CD 4 + T细胞，在识别 新抗原驱动肿瘤特异性抗肿瘤免疫，导致肿瘤消退。这些新抗原可以 从黑色素瘤中鉴定出来并用作免疫治疗的治疗靶点。我们进一步假设 新抗原特异性CD 4 + T细胞可以被工程化以改善它们的T细胞持久性和细胞溶解性， 活性与抗PD-1阻断剂组合。基于这些前提，我们建议识别新的 新抗原，重点是MHC II类新抗原，使用全基因组测序分析和遗传学方法， 靶向表达系统（Aim 1）。我们计划进一步研究是否有效的治疗性抗肿瘤药物 免疫可通过免疫显性新抗原和新型SAPNANO疫苗技术产生（Aim 2）。最后，我们继续我们的研究，以确定是否SAPNANO疫苗诱导或T细胞转移免疫 可以通过免疫检查点阻断或重编程T细胞以改善其细胞毒性来进一步增强， (Aim 3）。总之，我们所提议的研究的成功完成将有可能改变范式， 为包括黑色素瘤在内的多种癌症开发新的免疫疗法。

PROJECT ABSTRACT Recent clinical trials, using checkpoint blockade, antigen-specific T cell receptor (TCR) or CD19-chimeric antigen receptor (CAR), have shown promising clinical results for patients with metastatic cancer. However, despite the impressive and durable clinical response in cancer patients treated with anti-PD-1 antibody, more than 50% of cancer patients fail to respond to this checkpoint blockade treatment. Immunotherapy based on vaccines and TCR in many solid tumors is still lacking due to lack of tumor-specific targets. Therefore, new targets and strategies are urgently needed for the development of immunotherapeutic approaches for solid tumors including melanoma. Whole exome sequencing approach in combination with computer-assisted prediction algorithms has provided an exceptional opportunity to identify new patient-specific antigen targets for cancer immunotherapy. By taking advantage of next-generation sequencing and tumor-reactive T cells, we recently identified many neoantigens recognized by tumor-reactive CD4+ T cells as well as CD8+ T cells. Importantly, we found that some of CD4+ T clones with a single TCR could recognize multiple neoantigens, but not the corresponding wild-type antigens. Recent clinical studies show that mutation-specific CD4+ T cells can mediate tumor growth inhibition in melanoma and epithelial cancers, suggesting that CD4+ T cells play a critical role in inhibiting tumor growth and orchestrating overall antitumor immunity. However, clinical responses of cancer patients are correlated with the trafficking, persistence and cytotoxic ability of T cells. We show that CD4+ T cells can be reprogrammed to increase their cytotoxicity activity against cancer cells. Based on these premises, we hypothesize that neoantigen-specific T cells, in particular CD4+ T cells, play an important role in recognizing neoantigens that drive tumor-specific antitumor immunity, leading to tumor regression. These neoantigens can be identified from melanoma and exploited as therapeutic targets for immunotherapy. We further hypothesize that neoantigen-specific CD4+ T cells can be engineered for improving their T cell persistence and cytolytic activity in combination with anti-PD-1 blockade. Based on these premises, we propose to identify novel neoantigens with emphasis on MHC class II neoantigens using genome-wide sequencing analysis and a genetic targeting expression system (Aim 1). We further plan to investigate whether potent therapeutic antitumor immunity can be generated by immunodominant neoantigen and a novel SAPNANO vaccine technology (Aim 2). Finally, we pursue our studies to determine whether SAPNANO vaccine-induced or T cell transfer immunity can be further enhanced by immune checkpoint blockade or reprogramming T cells to improve their cytotoxicity, (Aim 3). In all, the successful completion of our proposed studies will potentially shift the paradigm by the development of novel immunotherapies for many types of cancer including melanoma.