Isolation and Characterization of Prostrate Antigen Specific High Affinity TCR

描述（申请人提供）：迄今为止，限制前列腺癌患者免疫治疗疗效的一个关键因素是前列腺癌细胞表达的TAA免疫原性差。这种较差的免疫原性可能是由于对前列腺正常细胞表达的抗原的免疫耐受性所致。因此，用于治疗前列腺癌的治疗性疫苗和过继性 T 细胞移植方法的开发多年来进展甚微。本申请中概述的研究利用了基因治疗方法，该方法能够重新定向正常外周血 T 细胞的特异性以识别肿瘤细胞。我们将利用这样一个事实，即我们的 T 细胞靶向的前列腺癌细胞表达的抗原肽不需要在前列腺癌患者中具有免疫原性，因为我们将为他们提供经过工程改造以识别其肿瘤的 T 细胞。鉴于女性缺乏前列腺，她们的 T 细胞不应耐受前列腺癌抗原。此外，它们的 T 细胞可能表达比男性类似 T 细胞对前列腺癌抗原具有更高亲和力的 T 细胞受体。因此，本申请提出从女性 PBL 中分离前列腺癌反应性 T 细胞克隆。然后，我们将从这些前列腺癌反应性 T 细胞中鉴定和克隆 T 细胞受体，并构建能够改造正常 PBL 衍生 T 细胞以识别前列腺癌细胞的逆转录病毒载体。然后我们将评估这些 TCR 转导的 T 细胞的体外和体内功效。虽然该应用将现有技术和已建立的免疫学概念应用于前列腺癌患者新疗法的开发，但我们相信 T 细胞的非正统来源为这项研究增添了新的转折。除了为前列腺癌患者提供新的治疗选择的潜力之外，这项研究还将增加我们对前列腺癌抗原耐受性的了解，这可能有助于开发新的前列腺癌疫苗。 公共健康相关性：该提案旨在分离具有与前列腺特异性膜抗原 (PSMA) 和前列腺干细胞抗原 (PSCA) 反应的高亲和力 T 细胞受体 (TCR) 的 T 细胞克隆，并在正常外周血 T 细胞上改造它们以识别前列腺癌细胞后表征其功效。我们提议的优势在于其创新假设，即从正常成年女性中分离的前列腺抗原反应性 T 细胞比从男性中分离的类似 T 细胞具有更高的亲和力并表达更高的亲和力 TCR。在成功完成该项目后，我们希望通过为局部和晚期前列腺癌患者提供经过高亲和力 TCR 改造的自身 T 细胞来识别和杀死肿瘤，从而避免局部和晚期前列腺癌患者的免疫耐受。

DESCRIPTION (provided by applicant): A key factor that has so far limited the efficacy of immunotherapy for prostate cancer patients is the poor immunogenicity of TAA expressed by prostate cancer cells. This poor immunogenicity is likely due to immunologic tolerance to antigens expressed by normal cells of the prostate. As a result, the development of therapeutic vaccines and adoptive T cell transfer approaches for treating prostate cancer has made little progress over the years. The studies outlined in this application take advantage of a gene therapy approach that is capable of redirecting the specificity of normal peripheral blood T cells to recognize tumor cells. We will take advantage of the fact that the antigenic peptides expressed by prostate cancer cells that are targeted by our T cells need not be immunogenic in prostate cancer patients since we would be providing them their own T cells engineered to recognize their tumors. Given that women lack prostate glands, their T cells should not be tolerant to prostate cancer antigens. Furthermore, their T cells may express T cell receptors with higher affinity for prostate cancer antigens than similar T cells in men. Therefore, this application proposes to isolate prostate cancer reactive T cell clones from the PBL of women. We will then identify and clone the T cell receptors from these prostate cancer reactive T cells and construct retroviral vectors capable of engineering normal PBL-derived T cells to recognize prostate cancer cells. We will then evaluate these TCR transduced T cells for their efficacy in vitro and in vivo. While this application applies existing technologies and established immunologic concepts to the development of new treatments for prostate cancer patients, we believe the unorthodox source of T cells adds a novel twist to this study. In addition to the potential for a new treatment option for prostate cancer patients, this study will increase our understanding of tolerance to prostate cancer antigens that may assist those in developing new prostate cancer vaccines. PUBLIC HEALTH RELEVANCE: This proposal is to isolate T cell clones bearing high affinity T cells receptors (TCR) reactive with prostate specific membrane antigen (PSMA) and prostate stem cell antigen (PSCA) and to characterize their efficacy after engineering them on normal peripheral blood T cells to recognize prostate cancer cells. The strength of our proposal is its innovative hypothesis that prostate antigen reactive T cells isolated from normal adult females would have higher avidity and express higher affinity TCRs than similar T cells isolated from males. On successful completion of this project we hope to circumvent immunologic tolerance in patients with local and advanced prostate cancer by providing them with their own T cells engineered with high affinity TCR to recognize and kill their tumors.