IMPROVING T CELL THERAPY OF NASOPHARYNGEAL CANCER

EB病毒(EBV)潜伏感染与鼻咽癌(NPC)有关。 表达EBV抗原LMP1和LMP2，这两个抗原都是免疫治疗的潜在靶点。临床研究： 鼻咽癌中的EB病毒特异性细胞毒T细胞(EBV-CTL)已经取得了可喜的结果，包括一些 完全应答，但其疗效有限，因为标准方法产生的EBV-CTL 1)以对鼻咽癌中表达的EBV蛋白LMP1和LMP2无反应的T细胞克隆为主，2) 输液后不能显著扩张，3)对NPC使用的免疫逃避策略敏感 如MHC-I类分子的表达下调以及调节性T细胞(Treg)的存在 肿瘤环境，以及4)鼻咽癌沉积内缺氧区功能障碍。我们的中心假设 克服这些限制将增强输注的CTL的抗肿瘤活性并改善 治疗结果。因此，我们将制备EBV-LMP1和LMP2特异性CTL(LMP-CTL)并评估 通过临床试验或异种移植模型来增强其活性的三种策略。目标1延长了我们的电流 LMP-CTL联合去淋巴CD45单抗治疗鼻咽癌的临床研究 增强CTL在体内的扩增，提高疾病应答率。在目标2中，我们将表达嵌合体 LMP-CTL中CD70的特异性抗原受体(CAR)。CD70在EBV阳性的鼻咽癌中高表达 因此，修饰的CTL应该能够通过MHC类L限制性和非限制性两种途径杀伤鼻咽癌细胞 在我们的异种移植模型中，提高了它们的治疗效果。此外，我们还将把 从CAR中的共刺激分子发出信号内域，并测试这些修饰是否会使 鼻咽癌中存在耐Tregs的CAR-LMP-CTL。在目标3中，我们将利用我们之前的观察 表明受缺氧诱导因子(HIF-IL2)调控的IL-2基因的表达可使CTL 耐缺氧的。我们将检测HIF-IL2表达的细胞持续性、增殖和功能 LMP-CTL在鼻咽癌肿瘤内的缺氧区，并确定它们是否产生增强的抗肿瘤活性。 这些目标与项目1-3中的目标相辅相成，但不重叠，因此从我们的 研究可以迅速被吸收到在该计划内的其他肿瘤中测试的策略中，并 反之亦然。LAV综述：人体对癌症的免疫防御通常会失败，因为 恶性肿瘤不会诱导或主动抑制免疫力。我们将尝试通过以下方式来抵消这些限制 工程杀伤T细胞识别癌细胞(LMP1和LMP2)上的结构并抵抗 由肿瘤细胞环境施加的防御。然后，T细胞的效果将在患者身上进行测试 鼻咽癌(NPC)。

Latent Epstein-Barr virus (EBV) infection is associated with nasopharyngeal carcinoma (NPC), which expresses the EBV antigens LMP1 and LMP2, both potential targets for immunotherapy. Clinical studies with EBV-specific cytotoxicT cells (EBV-CTLs) in NPC have already yielded promising results, including some complete responses, but their efficacy is limited because the EBV-CTL generated by standard methods are 1) dominated by T-cell clones not reactive to the EBV proteins LMP1 and LMP2 expressed in NPC, 2) cannot expand significantly after infusion, 3) are sensitive to immune evasion strategies employed by NPCs such as downregulation of MHC class I expression and the presence of regulatory T cells (Tregs) in the tumor environment, and 4) are dysfunctional in areas of hypoxia within NPC deposits. Our central hypothesis is that overcoming these limitations will enhance the antitumor activity of infused CTLs and improve treatment outcome. Thus, we will prepare EBV-LMP1 and LMP2-specific CTLs (LMP-CTLs) and evaluate three strategies to enhance their activity using a clinical trial or a xenograft model. Aim 1 extends our current Phase I clinical trials in NPC by combining LMP-CTL with lymphodepleting CD45 monoclonal antibodies to augment CTL expansion in vivo and improve disease response rates. In Aim 2, we will express a chimeric antigen receptor (CAR) specific for CD70 in LMP-CTLs. CD70 is overexpressed in EBV-positive NPCs, and the modified CTLs should thus be able to kill NPC cells through both MHC class l-restricted and unrestricted pathways, increasing their therapeutic effectiveness in our xenograft model. Moreover, we will incorporate signaling endodomains from costimulatory molecules in the CAR and test whether these modifications make the CAR-LMP-CTL resistant to Tregs present in NPC. In Aim 3, we will exploit our previous observations showing that expression of the IL-2 gene regulated by the hypoxia inducible factor (HIF-IL2) can render CTL resistant to hypoxia. We will measure cellular persistence, proliferation and function of HIF-IL2 expressing LMP-CTL in hypoxic areas within NPC tumors, and determine, if they produce enhanced antitumor activity. These aims complement but do not overlap with those in projects 1-3, such that advances emerging from our research could be rapidly assimilated into strategies being tested in other tumors within this program and vice versa. Lav Summary: The body's immune defenses against cancers often fail because the malignancies do not induce or actively inhibit immunity. We will try to counteract these limitations by engineering killer T cells to recognize structures on cancer cells (LMP1 and LMP2) and to resist the defenses imposed by the tumor cell environment. The effects of the T cells will then be tested in patients with nasopharyngeal carcinoma (NPC).