Heat Shock Protein Vaccine Dev: Glioma immunoresistance and PI(3)K/Akt/mTOR pathw

该项目的长期目标是优化恶性胶质瘤患者的免疫治疗。几 试验已经显示了神经胶质瘤疫苗的可行性、安全性和轶事功效。然而，将军 有效的神经胶质瘤免疫疗法的适用性还没有被清楚地证明。疫苗疗法 被设计为引起细胞免疫应答的免疫调节剂可能依赖于肿瘤特异性CD8 + T细胞和 尼古丁刺激的自然杀伤（NK）细胞。肿瘤特异性细胞溶解性CD8 + T细胞（CTL）可以经历 无反应性或细胞凋亡的神经胶质瘤表达的蛋白质，而NK细胞可以呈现 对肿瘤坏死因子相关凋亡诱导配体产生抗性的蛋白质无效 （TRAIL）介导的杀伤。B7-同源物1（B7-H1），也称为程序性死亡配体1（PD-L1），是一种免疫调节剂。 最近发现的通过诱导T细胞凋亡抑制抗肿瘤免疫的细胞表面蛋白， 削弱细胞因子的产生，并降低活化T细胞的细胞毒性。含FADD抑制剂 caspase-8裂解短蛋白（FLIPS）的表达可能会对TRAIL介导的NK细胞杀伤产生抗性。我们 认为肿瘤特异性蛋白如B7-H1和FLIPS可以限制胶质瘤的疗效 免疫疗法在我们的初步研究结果中，我们发现B7-H1和FLIPS受到细胞外基质的正调控。 PI（3）K/Akt/mTOR通路，并且具有该通路激活的胶质瘤细胞具有免疫抗性。在 此外，我们表明，含有胶质瘤衍生热休克蛋白的自体患者特异性疫苗， 肽复合物-96（HSPPC-96）似乎是安全的，同时引起肿瘤特异性T细胞应答和肿瘤特异性免疫应答。 增加循环NK细胞。为了将我们的实验结果转化为临床，我们将测试 假设胶质瘤中PI（3）K/Akt/mTOR通路激活抑制了先天性（NK细胞）， 适应性（T细胞）抗神经胶质瘤免疫应答。为了在临床相关的体外实验中检验我们的假设， 系统，目标#1和#2利用直接来自多形性胶质母细胞瘤（GBM）患者的胶质瘤细胞， 作为异种移植物传代，然后培养以评估PI（3）K/Akt/mTOR途径对抗性的影响 NK细胞和T细胞的杀伤。在目标3中，我们将研究直接从患者身上取下的胶质瘤，以评估其对神经胶质瘤的影响。 PI（3）K/Akt/mTOR通路活化与T细胞浸润之间的关系，在目标4中，我们将测试 我们的假设在正在进行的神经胶质瘤患者的HSPPC-96 I/II期疫苗试验的背景下。

The long-term goal of this project is to optimize immunotherapy for patients with malignant glioma. Several trials have shown the feasibility, safety, and anecdotal efficacy of glioma vaccines. However the general applicability of effective glioma immunotherapy has yet to be clearly documented. Vaccine therapies designed to provoke a cellular immune response may depend upon both tumor specific CD8+ T-cells and cytokine-stimulated natural killer (NK) cells. Tumor-specific cytotolytic CD8+ T-cells (CTLs) can undergo anergy or apoptosis in response to proteins expressed by gliomas, while NK cells may be rendered ineffective by proteins that confer resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated killing. B7-Homologue 1 (B7-H1), also known as programmed death ligand 1 (PD-L1), is a recently discovered cell surface protein that inhibits anti-tumor immunity by inducing T-cell apoptosis, impairing cytokine production, and diminishing the cytotoxicity of activated T-cells. FADD-containing inhibitor of caspase-8 cleavage short protein (FLIPS) may confer resistance to TRAIL-mediated NK cell killing. We believe that tumor specific proteins such as B7-H1 and FLIPS can limit the efficacy of glioma immunotherapy. In our preliminary results, we show that B7-H1 and FLIPS are positively regulated by the PI(3)K/Akt/mTOR pathway, and that glioma cells with this pathway activated are immunoresistant. In addition we show that an autologous patient-specific vaccine containing glioma-derived heat shock protein peptide complex-96 (HSPPC-96) appears to be safe, while evoking a tumor specific T-cell response and an increase in circulating NK cells. To translate our experimental findings into the clinic, we will test the hypothesis that activation of the PI(3)K/Akt/mTOR pathway in glioma suppresses innate (NK cell) and adaptive (T-cell) anti-glioma immune responses. In order to test our hypothesis in a clinically relevant in vitro system, aims #1 and #2 utilize glioma cells directly from glioblastoma multiforme (GBM) patients and passaged as xenografts, prior to culturing to assess the impact of PI(3)K/Akt/mTOR pathway on resistance to NK and T cell killing. In aim #3 we will study gliomas taken directly from patients to assess the relationship between PI(3)K/Akt/mTOR pathway activation and T-cell infiltration, and in aim #4 we will test our hypothesis within the context of an ongoing HSPPC-96 phase l/ll vaccine trial for glioma patients.