Recombinant Immunotherapy for Renal Cell Carcinoma

描述（由申请人提供）：尽管许多药物诱导细胞凋亡，但它们通常与损害健康的副作用相关。TRAIL（TNF相关凋亡诱导配体）/Apo-2L产生兴奋，因为它在广泛的肿瘤细胞中诱导凋亡，但在正常细胞和组织中不诱导凋亡。使用全身性TRAIL/Apo-2L剂量的临床前研究是安全的，并且可以抑制体内肿瘤生长。然而，需要大量的TRAIL/Apo-2L来抑制肿瘤形成，主要是因为该蛋白的体内半衰期短。因此，一种替代的递送方式可以增加TRAIL/Apo-2L的相对活性，使得更大、更成熟的肿瘤可以像更小的肿瘤一样有效地根除。今年在美国，将诊断出大约30，000例新的肾细胞癌（RCC）病例，预计近12，000例死于RCC。转移性RCC的中位生存期为8个月，几乎30%的RCC患者被诊断为晚期转移性疾病。此外，肾细胞癌对化疗具有高度耐药性，这可能是其与多药耐药P-糖蛋白相关的结果。RCC被认为是一种免疫原性肿瘤，许多自发消退的报道和肿瘤特异性免疫应答的证据是RCC免疫原性的强有力指标。因此，免疫疗法作为RCC的治疗方法正在被深入研究。不幸的是，反应率一直很差，并报告了显着的毒性，限制了免疫疗法在RCC治疗中的使用。基因转移治疗为肾细胞癌的治疗提供了新的选择。非复制型病毒基因传递系统的使用使得将基因直接原位施用到肿瘤中成为可能。先前，我们描述了重组TRAIL/Apo-2L蛋白对人RCC细胞系的细胞毒活性，以及编码人TRAIL基因的重组复制缺陷型腺病毒载体（Ad 5-TRAIL）的开发和测试。使用免疫缺陷小鼠，将TRAIL基因在体外和体内转移到人肿瘤细胞中，导致TRAIL/Apo-2L蛋白的快速产生和表达，以及肿瘤细胞的凋亡死亡。然而，Ad 5-TRAIL是否会抑制免疫活性动物的肿瘤生长，以及Ad 5-TRAIL诱导的肿瘤细胞死亡是否会激活系统性抗肿瘤免疫，仍然是未知的。考虑到这一点，拟议的项目将采用一种新型的腺病毒载体编码小鼠TRAIL基因（Ad 5-mTRAIL）与药剂相结合，通过增强抗原呈递和刺激T细胞扩增来增强全身免疫反应，以开发治疗RCC的独特方法。具体目标：（1）研究DC提呈来自凋亡Renca细胞的抗原以刺激抗肿瘤免疫的能力，并分析肿瘤排斥的效应细胞和机制;（2）研究Gelfoam R和缩肽（FR 901228）增强Ad 5-mTRAIL感染性和转基因表达的能力，使Ad 5-mTRAIL基因转移治疗更有效。

DESCRIPTION (provided by applicant): Although many agents induce apoptosis, they are commonly associated with side effects that compromise health. TRAIL (TNF-related apoptosis-inducing ligand)/Apo-2L is generating excitement because it induces apoptosis in a wide range of tumor cells but not in normal cells and tissues. Preclinical studies using systemic TRAIL/Apo-2L doses are safe and can suppress tumor growth in vivo. Large amounts of TRAIL/Apo-2L are, however, needed to inhibit tumor formation, primarily because of the short in vivo half-life of the protein. Therefore, an alternative means of delivery may increase the relative activity of TRAIL/Apo-2L such that larger, more established tumors can be eradicated as efficiently as smaller tumors. This year in the U.S. approximately 30,000 new cases of renal cell carcinoma (RCC) will be diagnosed and nearly 12,000 deaths are expected from RCC. Metastatic RCC carries a median survival of 8 months and almost 30% of RCC patients are diagnosed with advanced metastatic disease. Furthermore, RCC is highly resistant to chemotherapy, a possible consequence of its association with the multidrug-resistance P-glycoprotein. RCC is regarded as an immunogenic tumor, with many reports of spontaneous regression and evidence of tumor-specific immune responses being a strong indicator of the immunogenicity of RCC. Thus, immunotherapy is being intensely studied as a treatment for RCC. Unfortunately, the response rates have been poor and significant toxicity reported, limiting the use of immunotherapy in the treatment of RCC. Gene transfer therapy offers new alternatives in the treatment of RCC. Employment of non-replicative viral gene delivery systems is making it possible to administer genes directly into tumors in situ. Previously, we described the cytotoxic activity of recombinant TRAIL/Apo-2L protein against human RCC cell lines, and the development and testing of a recombinant, replication-deficient adenoviral vector encoding the human TRAIL gene (Ad5-TRAIL). Transfer of the TRAIL gene into human tumor cells in vitro and in vivo, using immunodeficient mice, led to the rapid production and expression of TRAIL/Apo-2L protein, and apoptotic death of the tumor cells. However, it remains unknown whether Ad5-TRAIL will inhibit tumor growth in immunocompetent animals, and if the Ad5-TRAIL-induced tumor cell death will activate systemic antitumor immunity. With this in mind, the proposed project will employ a novel adenoviral vector encoding the mouse TRAIL gene (Ad5-mTRAIL) combined with agents to boost systemic immune responses through augmenting antigen presentation and stimulating T cell expansion to develop unique approaches for the treatment of RCC. Specific Aims: (1) Investigate the ability of DC to present antigens derived from apoptotic Renca cells to stimulate antitumor immunity and analyze the effector cells and mechanism of tumor rejection; and (2) Examine the ability of Gelfoam R and depsipeptide (FR901228) to augment Ad5-mTRAIL infectivity and transgene expression, making Ad5-mTRAIL gene transfer therapy more potent.