In Vivo Imaging of Antigen-Specific T Cells in Mice/Huma

小鼠/Huma 中抗原特异性 T 细胞的体内成像

• 批准号: 7039724
• 负责人: ANTONI RIBAS
• 金额: $ 16.25万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7039724
• 关键词: Lentivirus; Retroviridae; T cell receptor; T lymphocyte; bioimaging /biomedical imaging; cell transplantation; clinical trial phase I; human subject; human therapy evaluation; laboratory mouse; melanoma; monophenol monooxygenase; neoplasm /cancer immunology; neoplasm /cancer immunotherapy; passive immunization; patient oriented research; positron emission tomography; reporter genes; transfection /expression vector; tumor antigens

Malignant melanoma is notoriously resistant to cytotoxic therapies. However, both spontaneous remissions and durable responses to a variety of immunotherapy strategies occur in melanoma. The adoptive transfer of cloned antigen-specific T cells, a laborious technique, has resulted in the highest response rates. In order to make this mode of melanoma immunotherapy more widely applicable, a strategy that minimizes ex vivo manipulation of cells would be desirable. Additionally, clinical development of such a strategy relies on the availability of assays to efficiently study the performance of tumor antigen-specific cells in vivo. The monitoring of immune responses to cancer is currently based on ex vivo assays; e.g. MHC tetramer and ELISPOT assays, which use lymphocytes sampled from peripheral blood. Their use as surrogate endpoints for the clinical development of immunotherapy strategies has obvious caveats, the main ones being (i) the sampling of cells at the wrong compartment (the blood and not the tumor) and (ii) not allowing a dynamic evaluation of the T cell responses. We hypothesized that lymphocytes engineered to express both a transgenic T cell receptor (TCR) specific for a defined melanoma antigen and a PET reporter gene can be used to study non-invasively the in vivo kinetics of antitumor T cell responses. This system would allow the efficient generation of a population of antigen-specific T cells labeled with a PET reporter gene for adoptive transfer, which could then be tracked in vivo by serial PET scanning to determine their population dynamics and ability to home to antigen-matched tumors. We propose a 3-aim project that builds upon the experience in the in vivo imaging of antigen-specific T cell responses in mice generated during the current UCLA ICMIC funding period. In Aim 1 we plan to construct and test in vitro retroviral and lentiviral vectors expressing the TCR for the melanoma antigen Tyrosinase (Tyr) and the HSV1-sr39tk PET reporter gene. In Aim 2 we propose a murine model to image the in vivo kinetics of genetically modified murine splenocytes and hematopoietic stem cells (HSC) expressing both the Tyr-TCR and HSV1-sr39tk. We will serially image their ability to repopulate lymphopenic hosts upon adoptive transfer, and traffic to antigen-matched experimental tumors in vivo. In Aim 3 we plan a phase I clinical trial in patients with metastatic melanoma. In this trial, we propose to administer increasing doses of Tyr-TCR-HSV1-sr39tk transgenic autologous cells after a non-myeloablative conditioning regimen and determine, by PET imaging, their ability to accumulate in Tyr-positive melanoma metastasis. In summary, we propose the preclinical and clinical testing of the ability to image tumor antigen-specific T cell responses against malignant melanoma.

众所周知，恶性黑色素瘤对细胞毒性疗法具有抵抗力。然而，两者都是自发的 黑色素瘤会出现对各种免疫治疗策略的缓解和持久反应。克隆抗原特异性 T 细胞的过继转移是一项费力的技术，但反应率最高。为了使这种黑色素瘤免疫治疗模式更广泛地应用，需要一种最大限度地减少细胞离体操作的策略。此外，这种策略的临床开发依赖于有效研究肿瘤抗原特异性细胞体内性能的检测方法的可用性。目前对癌症免疫反应的监测是基于离体检测；例如MHC 四聚体和 ELISPOT 检测，使用从外周血中采集的淋巴细胞。他们用作替代品 免疫治疗策略临床开发的终点有明显的警告，主要是 (i) 在错误的隔室（血液而不是肿瘤）进行细胞采样，以及 (ii) 不允许对 T 细胞反应进行动态评估。我们假设，经过改造的淋巴细胞可表达特定黑色素瘤抗原特异的转基因 T 细胞受体 (TCR) 和 PET 报告基因，可用于非侵入性研究 抗肿瘤 T 细胞反应的体内动力学。该系统将允许有效生成标记有 PET 报告基因的抗原特异性 T 细胞群，用于过继转移，然后可以通过连续 PET 扫描在体内进行跟踪，以确定其群体动态和归巢到抗原匹配的能力肿瘤。我们提出了一个三目标项目，该项目建立在当前 UCLA ICMIC 资助期间产生的小鼠抗原特异性 T 细胞反应体内成像经验的基础上。在目标 1 中，我们计划构建并测试体外逆转录病毒和慢病毒载体，表达黑色素瘤抗原酪氨酸酶 (Tyr) 的 TCR 和 HSV1-sr39tk PET 报告基因。在目标 2 中，我们提出了一个小鼠模型来成像 表达 Tyr-TCR 和 HSV1-sr39tk 的转基因小鼠脾细胞和造血干细胞 (HSC) 的体内动力学。我们将连续成像它们在过继转移后重新填充淋巴细胞减少宿主的能力，以及体内运输到抗原匹配的实验肿瘤的能力。在目标 3 中，我们计划对转移性黑色素瘤患者进行 I 期临床试验。在这项试验中，我们建议在非清髓性预处理方案后增加Tyr-TCR-HSV1-sr39tk转基因自体细胞的剂量，并通过PET成像确定它们在Tyr阳性黑色素瘤转移中积累的能力。总之，我们建议对针对恶性黑色素瘤的肿瘤抗原特异性 T 细胞反应进行成像的能力进行临床前和临床测试。