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

最近的临床试验表明，晚期黑色素瘤可以通过非清髓性化疗和自体过继T细胞免疫治疗􁈺AIT􁈻的组合来治疗，达到50%的临床反应率。然而，这种临床反应并不总是持久的。细胞毒性T细胞􁈺CTL􁈻在没有T细胞帮助的情况下寿命很短􁈺Th􁈻，输注后持久性有限。此外，在输注CD8􀵅显性肿瘤特异性T细胞系后，抗原􁈺Ag􁈻阴性变异发生，表明肿瘤很容易逃避集中治疗。我们的目标是通过提供功能表征的肿瘤Ag特异性CD4􀵅Th1细胞作为输注产品的核心成分，优化和扩展AIT到晚期乳腺癌。肿瘤Ag特异性CD4􀵅Th1细胞可以归巢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的功能􁈺APC􁈻。由此增加的内源性肿瘤细胞加工导致表位扩散。通过提供强大的CD4􀵅Th1免疫应答，肿瘤Ag特异性CD8􀵅T细胞将被激发，并且产生的应答将长期存在。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。我们对HER‐2/neu􁈺HER2􁈻‐过表达乳腺癌的III/IV期患者进行了疫苗试验，验证了该策略的有效性。如果接种MHC II类结合HER2衍生肽的患者不仅获得了增强的CD4􀵅T细胞对疫苗肽的应答，而且获得了T细胞对肿瘤表达但疫苗中不存在的其他HER2表位的应答，则证明了显著的生存优势。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􁈺DCs􁈻可以显著提高T细胞再输注时的治疗性能。此外，适当激活的dc可以促进T细胞的扩增，具有更高的功能亲和性，包括CD8􀵅细胞溶解T细胞，可以直接裂解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，使用与待激活T细胞在相同培养中同时产生的最佳活化的自体DC。我们还将评估这些培养方法是否会增加表位扩散。

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.