Optimized ex vivo expansion of anti-tumor Th1 and Tc1 for adoptive immunotherapy

描述(申请人提供)：最近的临床试验表明，晚期黑色素瘤可以用非清髓性化疗和自体过继T细胞免疫疗法(AIT)相结合的方法来治疗，临床缓解率达到50%。然而，这种临床反应并不是始终如一的。细胞毒性T细胞(CTL)在缺乏T细胞帮助(Th)的情况下生存时间短，输注后存留时间有限。此外，在输注以CD8+为主的肿瘤特异性T细胞系后，抗原(Ag)阴性的变异体出现，这表明肿瘤很容易逃脱集中治疗。我们的目标是通过提供具有功能特征的肿瘤抗原特异性的CD4+Th1细胞作为输注产品的中心成分，来优化和扩展AIT应用于晚期乳腺癌。肿瘤抗原特异性的CD4+Th1细胞可以定位于肿瘤，并分泌炎性细胞因子，调节微环境以增强局部抗原提呈细胞(APC)的功能。由此导致内源性肿瘤细胞的加工增加，导致表位扩散。通过提供强大的CD4+Th1免疫反应，肿瘤抗原特异性CD8+T细胞将被激发，并且所产生的反应将是长期的。我们的目标是促进肿瘤特异性、表位扩散、Th1型CD4+反应，作为有效AIT的重要组成部分。这一策略已经被我们自己的针对HER-2/neu(HER2)过表达乳腺癌的III/IV期患者的疫苗试验所验证。接种MHC Class II结合的HER2衍生多肽的患者如果不仅对疫苗多肽的CD4+T细胞反应增强，而且对他们的肿瘤表达但疫苗中缺失的额外HER2表位的T细胞反应增强，则显示出显著的生存优势。在动物实验中，我们观察到，在T细胞培养过程中加入自体树突状细胞(DC)可以显着提高重新输注时的T细胞治疗效果。此外，适当激活的DC可以促进具有较高功能亲和力的T细胞的扩张，包括CD8+细胞溶解T细胞，可以直接溶解MHC限制性肿瘤。我们建议开发一种临床相关的方法来体外扩增HER2特异性T细胞，使用在相同的培养条件下同时产生的最佳激活的自体DC作为待激活的T细胞。我们还将评估这些培养方法是否会增加表位传播。

DESCRIPTION (provided by applicant): Recent clinical trials have demonstrated that advanced melanoma can be treated with a combination of nonmyeloablative chemotherapy and autologous adoptive T cell immunotherapy (AIT) to achieve a 50% clinical response rate. Such clinical responses are not, however, consistently durable. Cytotoxic T cells (CTL) are shortlived in the absence of T cell help (Th), with limited persistence after infusion. Furthermore, antigen (Ag) negative variants develop after infusion of CD8+ predominant tumor specific T cell lines, suggesting tumors readily escape from focused therapy. Our goal is to optimize and extend AIT to advanced breast cancer by providing functionally characterized tumor Ag-specific CD4+ Th1 cells as a central component of the infused product. Tumor Ag-specific CD4+ Th1 cells can home to tumor and secrete inflammatory cytokines, modulating the microenvironment to enhance the function of local antigen presenting cells (APC). The resultant increased processing of endogenous tumor cells results in epitope spreading. By providing a robust CD4+ Th1 immune response, tumor Ag-specific CD8+ T cells will be elicited, and the response generated will be long lived. We aim to promote tumor-specific, epitope spreading, Th1-type CD4+ responses as an essential component of effective AIT. This strategy has been validated by our own vaccine trials for Stage III/IV patients with HER-2/neu (HER2)-overexpressing breast cancer. Patients vaccinated with MHC Class II-binding HER2-derived peptides evidenced a significant survival advantage if they achieved not only enhanced CD4+ T cell responses to vaccine peptides, but also T cell responses to additional HER2 epitopes expressed by their tumors but absent from the vaccine. In animal studies we observe that the inclusion of autologous dendritic cells (DCs) during T cell culture can markedly improve T cell therapeutic performance at the time of re-infusion. Moreover, appropriately activated DCs can promote the expansion of T cells with higher functional avidity, including CD8+ cytolytic T cells that can directly lyse MHC-restricted tumors. We propose to develop a clinically relevant method to expand HER2 specific T cells ex vivo, using optimally activated autologous DC generated simultaneously in the same cultures as the T cells to be activated. We will also assess whether these culture methods increase epitope spreading.