Reversal of CMV-specific Immune Deficits in Patients with Glioblastoma

包括我们在内的四个独立实验室最近发现并证实， 经常与人巨细胞病毒抗原的表达相关，这提供了一个独特的机会， 利用免疫系统的细胞溶解能力根除CMV感染的肿瘤细胞， 正常的大脑周围。我们在使用CMV pp 65 RNA增强CMV特异性免疫应答方面的努力- 脉冲的树突状细胞（DC）已经证明了增强CMV特异性细胞和体液免疫的能力。 在新诊断的GBM患者中获得有希望的放射学和临床反应。 尽管有这些令人鼓舞的结果，我们发现GBM患者引起了深刻的免疫CMV- 诊断时的特异性缺陷，其特征在于不能安装有效的多功能T细胞 刺激后的应答（同时产生IL-2、IFN、TNF和溶细胞颗粒（CD 107）） 体外CMV抗原。多功能性T细胞应答已显示介导对免疫缺陷的有效控制。 慢性病毒感染，如人类的HIV和CMV，而DC疫苗接种提高了 单功能CMV特异性T细胞，多功能反应没有增强。重要的是，我们发现 多功能CMV特异性T细胞反应可以在体外使用pp 65在这些相同的患者中恢复， 加入外源性IL-2或通过去除CD 4 + CD 25 + FOXP 3 + 调节性T细胞（Tcells）。结果表明，逆转体内细胞介导的缺陷， 在GBM患者中的治疗可能是一个可行的目标，并可能显着提高抗肿瘤的疗效。 免疫疗法在这项提案中，我们将探索逆转细胞介导的缺陷的方法， 使用CMV RNA脉冲的DC的GBM，所述DC与编码细胞因子的RNA共转染，所述细胞因子有利地调节 多功能T细胞应答并抑制免疫抑制性T细胞的扩增。使用RNA修饰的 DC可以允许免疫调节细胞因子的靶向递送，而不诱导全身性免疫应答。 毒性或全身性Treg抑制的自身免疫风险。这些研究有很大的潜力来改善 GBM患者的临床结局。

The recent discovery and confirmation by four independent laboratories, including ours, that malignant gliomas are frequently associated with expression of human cytomegalovirus antigens provides a unique opportunity to harness the cytolytic power of the immune system to eradicate CMV-infected tumor cells without harming surrounding normal brain. Our efforts in enhancing CMV-specific immune responses using CMV pp65 RNA- pulsed dendritic cells (DCs) have demonstrated the capacity to enhance CMV-specific cellular and humoral responses and elicit promising radiographic and clinical responses in patients with newly-diagnosed GBM. Despite these encouraging results, we have found that patients with GBM elicit profound immunologic CMV- specific deficts at diagnosis that are characterized by the inability to mount effective polyfunctional T cell responses (simultaneous production of IL-2, IFN, TNF, and cytolytic granules (CD107)) upon stimulation with CMV antigens in vitro. Polyfunctional T cell responses have been shown to mediate the effective control of chronic viral infections such as HIV and CMV in humans, and while DC vaccination improved the frequency of monofunctional CMV-specific T cells, polyfunctional responses were not enhanced. Importantly, we have found that polyfunctional CMV-specific T cell responses could be restored in these same patients in vitro using pp65 RNA pulsed DCs coupled with addition of exogenous IL-2 or through the removal of CD4+CD25+FOXP3+ regulatory T cells (Tregs) prior to stimulation. The results suggest that reversal of cell-mediated deficits in vivo in patients with GBM may be a feasible goal and may significantly improve the efficacy of antitumor immunotherapy. In this proposal, we will explore methods to reverse cell-mediated deficits in patients with GBM using CMV RNA pulsed DCs co-transfected with RNAs encoding for cytokines that favorably modulate polyfunctional T cell responses and inhibit expansion of immunosuppressive Tregs. The use of RNA-modified DCs may allow for the targeted delivery of immunomodulatory cytokines without the induction of systemic toxicity or autoimmune risks of systemic Treg inhibition. These studies have significant potential to improve clinical outcomes for patients with GBM.