Dendritic Cell-Based Genetic Immunotherapy for Melanoma

基于树突状细胞的黑色素瘤基因免疫疗法

• 批准号: 7012681
• 负责人: James S. Economou
• 金额: $ 32.39万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7012681
• 关键词: CD28 molecule; CD8 molecule; SCID mouse; antitumor antibody; clinical research; clinical trial phase I; clinical trial phase II; dendritic cells; enzyme linked immunosorbent assay; gene targeting; gene therapy; genetically modified animals; human subject; human therapy evaluation; laboratory mouse; melanoma; natural killer cells; neoplasm /cancer immunology; neoplasm /cancer immunotherapy; neoplasm /cancer vaccine; patient oriented research

DESCRIPTION (provided by applicant): This is a competitive renewal for ROI CA79976 "Dendritic cell-based genetic immunotherapy for melanoma" in which we request support for years 05-08. Our accomplishments in the previous funding period include: 1. defining the immunological events taking place in a murine melanoma model using dendritic cell (DC) engineered with a defined tumor antigen MART-1, 2. completing a phase l/II clinical trial in melanoma patients receiving MART-1/27-35 peptide pulsed DC and 3. opening a gene therapy trial using adenovirus (AdV) MART-1-transduced DC. Based on this progress, we propose to continue our translational studies of genetic immunotherapy of human melanoma centered around three specific aims. Aim 1: Genetic Immunotherapy in a CDS-Deficient Environment. We have made the remarkable and original observations that CD8 or Class I knock out mice immunized with AdVMART1-transduced DC have superior levels of protection to B16 melanoma than wild type (wt) mice. Since wt mice depleted of CD8 cells are unable to generate protective immunity, CD8 KO mice have developed a compensatory mechanism from generating robust tumor immunity to DC vaccination. We present preliminary evidence that this antitumor immunity is mediated by collaboration between effector cells of the innate (NK-like) and adaptive (CD4) arms of the immune systems. We propose to characterize the underlying mechanism. Aim 2: The Biology of Class I and Class II-Restricted T Cell Responses in AdVMART1/DC Immunized Patients with Melanoma. This clinical trial, in which patients with stage IV MART-1-positive melanoma are immunized with AdVMART1/DC, provides a unique opportunity to define immunological events triggered by genetic immunization to a defined "self" tumor antigen. Only two epitopes have been described for this small protein-HLA-A2.1-restricted MART-1/27-35 and HLA-DK4 restricted MART-1/51-73. Using ELISPOT and tetramer assays for this class I and II epitopes, we will quantitate, isolate and study MART-1-reactive CD8 and CD4 T cell in immunized patients. We will also study the role of determinant spreading and cross-presentation in clinical response, the biology of DC used for vaccination and the possible participation of innate (NK) immunity in DC-based immunotherapy. Aim 3: CTLA4 Blockade in Clinical Dendritic Cell-Based Immunotherapy. DC-based immunotherapy generates occasional but dramatic clinical antitumor responses. We have closely studied one subject in whom the administration of MART-1/DC vaccines was followed by a CTLA4 blocking antibody. Immunological analysis suggests that the antitumor immune response initiated by the DC vaccines was maintained by CTLA4 blockade. To test this hypothesis, we have designed a phase II randomized trial with the primary goal of detecting the effect of MART-1/27-35/DC + CTLA4 blockade on the frequency of melanoma antigen-specific activated T cells using ELISPOT assays. This trial will provide insight in the autoregulatory mechanisms that govern the activity of DC-based immunotherapy. In summary, we propose to continue our translational program in genetic immunotherapy with an emphasis on immune mechanism and clinical hypothesis-testing.

描述（由申请人提供）：这是 ROI CA79976“基于树突状细胞的黑色素瘤基因免疫疗法”的竞争性更新，我们请求 05-08 年的支持。我们在上一资助期间取得的成就包括：1. 使用用确定的肿瘤抗原 MART-1 设计的树突状细胞 (DC) 定义了小鼠黑色素瘤模型中发生的免疫事件，2. 完成了黑色素瘤的 I/II 期临床试验接受 MART-1/27-35 肽脉冲 DC 的患者和 3. 使用腺病毒 (AdV) MART-1 转导的 DC 开展基因治疗试验。基于这一进展，我们建议围绕三个具体目标继续进行人类黑色素瘤基因免疫治疗的转化研究。目标 1：CDS 缺陷环境中的基因免疫治疗。我们做出了引人注目的原创观察，即用 AdVMART1 转导的 DC 免疫的 CD8 或 I 类敲除小鼠对 B16 黑色素瘤的保护水平优于野生型 (wt) 小鼠。由于CD8细胞耗尽的wt小鼠无法产生保护性免疫，因此CD8 KO小鼠已经发展出一种从产生强大的肿瘤免疫到DC疫苗接种的补偿机制。我们提出的初步证据表明，这种抗肿瘤免疫是由免疫系统的先天性（NK 样）和适应性（CD4）臂的效应细胞之间的协作介导的。我们建议描述潜在机制的特征。目标 2：AdVMART1/DC 免疫的黑色素瘤患者中 I 类和 II 类限制性 T 细胞反应的生物学。这项临床试验使用 AdVMART1/DC 对 IV 期 MART-1 阳性黑色素瘤患者进行免疫，提供了一个独特的机会来定义由针对特定“自身”肿瘤抗原的基因免疫引发的免疫事件。对于这种小蛋白，仅描述了两个表位——HLA-A2.1限制性MART-1/27-35和HLA-DK4限制性MART-1/51-73。使用 ELISPOT 和四聚体测定法检测 I 类和 II 类表位，我们将定量、分离和研究免疫患者中 MART-1 反应性 CD8 和 CD4 T 细胞。我们还将研究决定簇传播和交叉呈递在临床反应中的作用、用于疫苗接种的 DC 生物学以及先天 (NK) 免疫在基于 DC 的免疫治疗中的可能参与。目标 3：临床树突状细胞免疫疗法中的 CTLA4 阻断。基于 DC 的免疫疗法偶尔会产生显着的临床抗肿瘤反应。我们仔细研究了一名受试者，该受试者在接种 MART-1/DC 疫苗后又接种了 CTLA4 阻断抗体。免疫学分析表明 DC 疫苗引发的抗肿瘤免疫反应是通过 CTLA4 阻断维持的。为了检验这一假设，我们设计了一项 II 期随机试验，主要目标是使用 ELISPOT 检测检测 MART-1/27-35/DC + CTLA4 阻断对黑色素瘤抗原特异性激活 T 细胞频率的影响。该试验将深入了解控制 DC 免疫疗法活性的自身调节机制。总之，我们建议继续基因免疫治疗的转化计划，重点是免疫机制和临床假设检验。