The roles of EBV-specific T cells in response to checkpoint blockade immunotherapy of EBV-driven nasopharyngeal carcinoma

项目摘要/摘要 鼻咽癌(NPC)是一种由EB病毒(EBV)引起的恶性肿瘤，是东方和中东的地方性疾病。 东南亚。地方性鼻咽癌的总体5年存活率只有51%，这是一个没有得到满足的临床病例。 需要。虽然已知鼻咽癌感染EBV并表达PD-L1，但对其作用知之甚少。 EBV特异性T细胞在鼻咽癌控制和抗PD-1治疗中的有效率较低(ORR~20%)。 这项研究的目的是为了更好地了解EBV特异性T细胞反应在鼻咽癌免疫病理中的作用 和免疫治疗反应。我们将检验特定的假设：1.EBV特异性T细胞有助于 联合抗PD-1和抗CTLA-4检查点阻断免疫治疗对肿瘤的控制作用； 外周EBV特异性T细胞的表型和克隆性特征/动力学可用于 鼻咽癌患者的临床结局指标。为了检验这些假设，我们将利用我们对两个 新加坡鼻咽癌患者队列：1.51例新诊断的鼻咽癌患者队列 PBMC和档案FFPE组织可用，队列2。参与II期的50名患者队列 试验(NCT03097939-新加坡国家癌症中心)测试Ipilumimab和Ipilumimab的组合 Nivolumimab(Ipi.+Nivo.)采用纵向采集的PBMC和组织活检进行免疫治疗。最近 发表的这项临床试验的初步分析(AACR 2020)显示，联合使用IPI.+NIVO。治疗是安全的 在复发和转移的鼻咽癌患者中取得了持久的反应，并确定了负相关 循环EBV-DNA水平和应答之间的关系。此外，新诊断的鼻咽癌初步分析 来自队列1的患者外周血样本显示CD8+的某些表型特征之间存在关联 T细胞和临床参数，如EBV-DNA水平。因此，在目标1中，我们将调查临床 这些初步确定的鼻咽癌相关CD8+T细胞表型的相关性。除了深入的单曲 这些细胞的细胞转录、功能TCR序列分析、细胞成像、转录分析和 对患者匹配的肿瘤进行大量TCR测序将有助于发现外周T细胞之间的新关联 细胞和肿瘤微环境。在目标2中，我们将表征鼻咽癌中EBV特异性T细胞反应 联合治疗过程中的周边和肿瘤微环境。免疫疗法寻找新的治疗方法 EB病毒特异性T细胞表型特征与免疫治疗反应的关系。在AIM 3.我们将研究与治疗诱导的鼻咽癌特异性变化相关的T细胞克隆动力学 外周血和肿瘤活检标本中TCR克隆多样性的免疫应答比较 治疗的不同阶段。总体而言，鼻咽癌周围组织中EBV特异性T细胞表型的特征 而肿瘤采用多种尖端方法不仅可以提高我们对鼻咽癌的认识 免疫格局，但也可能识别临床相关的EBV特异性T细胞表型 在未来的鼻咽癌免疫治疗试验中进行了测试。

Project Summary/Abstract Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-driven malignancy that is endemic to East and Southeast Asia. The overall 5-year survival rate for endemic NPC is only 51%, which represents an unmet clinical need. While NPC tumors are known to be infected with EBV and express PD-L1, little is known about the role of EBV-specific T cells in the control of NPC and anti-PD-1 therapy has shown a low rate of efficacy (ORR ~20%). The goal of this study is to better understand the role of EBV-specific T cell responses in NPC immunopathology and immunotherapeutic response. We will test the specific hypotheses that: 1. EBV-specific T cells contribute to tumor control elicited by combination anti-PD-1 and anti-CTLA-4 checkpoint blockade immunotherapy, and 2. that the phenotypic and clonal characteristics/dynamics of peripheral EBV-specific T cells can be useful as indicators of clinical outcomes for NPC patients. To test these hypotheses, we will leverage our access to two Singaporean NPC patient cohorts: Cohort 1. A 51-patient cohort of new-diagnosis NPC for which viably frozen PBMCs and archival FFPE tissues are available and Cohort 2. A 50-patient cohort participating in a phase II trial (NCT03097939 - National Cancer Centre Singapore) testing the combination of Ipilumimab and Nivolumimab (Ipi.+Nivo.) immunotherapy with longitudinally collected PBMCs and tissue biopsies. Recently published preliminary analysis (AACR 2020) from this clinical trial shows that combined Ipi.+Nivo. therapy is safe and achieved durable responses in recurrent and metastatic NPC patients and identified a negative association between circulating EBV-DNA levels and response. In addition, preliminary analysis of new-diagnosis NPC patient peripheral blood samples from Cohort 1 show associations between certain phenotypic profiles of CD8+ T cells and clinical parameters such as EBV-DNA levels. Therefore, in Aim 1. we will investigate the clinical relevance of these preliminarily identified NPC-associated CD8+ T cell phenotypes. In addition to in-depth single cell transcriptional, functional TCR sequence profiling of these cells, cellular imaging, transcriptional profiling and bulk TCR sequencing of patient-matched tumor will allow discovery of novel associations between peripheral T cells and the tumor microenvironment. In Aim 2., we will characterize EBV-specific T cell responses in the NPC periphery and tumor microenvironment during combination Ipi.+Nivo. immunotherapy treatment to identify novel associations between the phenotypic profiles of EBV-specific T cells and immunotherapeutic response. In Aim 3., we will investigate T cell clonal dynamics associated with treatment induced changes to the NPC-specific immune response by comparing the TCR clonal diversity in peripheral blood and tumor biopsy samples from different stages of treatment. Overall, characterization of EBV-specific T cells phenotypes in the NPC periphery and the tumor using multiple cutting-edge approaches will not only improve our understanding of the NPC immune landscape, but also potentially identify clinically relevant EBV-specific T cell phenotypes that could be tested in future NPC immunotherapy trials.