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。几个 试验已经证明了胶质瘤疫苗的可行性、安全性和坊间疗效。然而，将军 有效的胶质瘤免疫治疗的适用性尚未得到明确的证明。疫苗疗法 旨在激发细胞免疫反应的设计可能取决于肿瘤特异性CD8+T细胞和 细胞因子刺激的自然杀伤(NK)细胞。肿瘤特异性细胞溶解CD8+T细胞(CTL)可以 对胶质瘤表达的蛋白的无能或凋亡反应，而NK细胞可能被呈现 对肿瘤坏死因子相关的凋亡诱导配体产生抵抗的蛋白质无效 (TRAIL)-中介杀戮。B7-同源1(B7-H1)，也称为程序性死亡配体1(PD-L1)，是一种 最近发现的细胞表面蛋白通过诱导T细胞凋亡来抑制抗肿瘤免疫， 抑制细胞因子的产生，降低激活的T细胞的细胞毒作用。含FADD的缓蚀剂 Caspase-8裂解短蛋白(Flips)的表达可能对TRAIL介导的NK细胞杀伤产生抵抗。我们 认为肿瘤特异性蛋白如B7-H1和FLOPS可以限制胶质瘤的疗效 免疫疗法。在我们的初步结果中，我们表明B7-H1和Flips受到 PI(3)K/Akt/mTOR通路，且激活该通路的胶质瘤细胞具有免疫抗性。在……里面 此外，我们还发现了一种含有胶质瘤热休克蛋白的自体患者特异性疫苗。 多肽复合体-96(HSPPC-96)似乎是安全的，同时可以激发肿瘤特异性T细胞反应和 循环中的NK细胞增多。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通路的激活抑制了先天(NK细胞)和 适应性(T细胞)抗胶质瘤免疫反应。为了在临床相关的体外实验中验证我们的假设 系统，AIMS#1和#2直接利用来自多形性胶质母细胞瘤(GBM)患者的胶质瘤细胞和 作为异种移植细胞传代，在培养前评估PI(3)K/Akt/mTor通路对耐药性的影响 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提取的胶质瘤，以评估 PI(3)K/Akt/mTOR通路激活与T细胞浸润的关系，在Aim#4中，我们将测试 我们的假设是在正在进行的针对胶质瘤患者的热休克蛋白-96阶段L/11期疫苗试验的背景下进行的。

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.