ENHANCING HPV-16 E6-SPECIFIC ANTITUMOR IMMUNITY

描述（由申请方提供）：针对人乳头瘤病毒（HPV）E6蛋白的免疫疗法可能为控制HPV相关宫颈恶性肿瘤提供机会。已经确定T细胞介导的免疫是抵抗HPV相关病变的最重要的组成部分之一，并且树突状细胞（DC）是体内最有效的专职抗原呈递细胞（APC），其引发辅助和杀伤T细胞。此外，已经表明，通过基因枪皮内施用DNA疫苗代表了将DNA疫苗递送到体内专业APC的有效手段。因此，我们使用基因枪递送系统来测试需要将DNA疫苗直接递送到专业APC的策略。我们已经成功地测试了几种细胞内靶向策略，增强MHC I类和II类加工和呈递，并产生了令人印象深刻的结果。最近，我们测试了多种抗凋亡因子与DNA疫苗共同给药时增强DC存活和抗原特异性CD 8 + T细胞免疫应答的能力。由于细胞内靶向和抗凋亡策略通过不同的机制修饰DC，我们已经能够将用于延长DC寿命的联合收割机抗凋亡策略与用于增强DC对MHC I类和II类抗原的呈递的细胞内靶向策略组合以提高DNA疫苗效力。虽然编码抗原的DNA与编码抗凋亡蛋白的DNA的共施用可显著增强DNA疫苗效力，但编码抗凋亡蛋白的DNA的使用引起了与致癌性相关的显著关注。一种相对较新的技术，使用靶向促凋亡蛋白的小干扰RNA（siRNA）的RNA干扰（RNAi）可以提供类似的效果，同时减轻对致癌性的担忧。因此，在目前的提案中，我们计划测试的假设，即皮内递送编码HPV-16 E6的DNA疫苗结合siRNA靶向关键促凋亡蛋白的抗原表达树突状细胞将延长转染的DC寿命，并导致增强E6特异性T细胞介导的免疫应答和体内抗肿瘤作用。

DESCRIPTION (provided by applicant): Immunotherapy that targets the human papillomavirus (HPV) E6 protein may provide an opportunity to control HPV-associated cervical malignancies. It has been established that T cell-mediated immunity is one of the most crucial components of defense against HPV-associated lesions and that dendritic cells (DCs) are the most potent professional antigen presenting cells (APCs) that prime helper and killer T cells in vivo. Furthermore, it has been shown that intradermal administration of DNA vaccines via gene gun represents an efficient means of delivering DNA vaccines into professional APCs in vivo. We have therefore used the gene gun delivery system to test strategies that require direct delivery of DNA vaccines to professional APCs. We have successfully tested several intracellular targeting strategies that enhance MHC class I and class II processing and presentation and have generated impressive results. Recently, we tested a variety of anti-apoptotic factors for their ability to enhance DC survival and antigen-specific CD8+ T cell immune responses when co-administered with DNA vaccines. Because intracellular targeting and anti-apoptotic strategies modify DCs via different mechanisms, we have been able to combine anti-apoptotic strategies for prolonging DC life with intracellular targeting strategies for enhancing MHC class I and II presentation of antigen by DCs to improve DNA vaccine potency. While coadministration of DNA encoding antigen with DNA encoding anti-apoptotic proteins can significantly enhance DNA vaccine potency, the use of DNA encoding anti-apoptotic proteins raises significant concerns related to oncogenicity. A relatively new technology, RNA interference (RNAi) using small interfering RNA (siRNA) targeting pro-apoptotic proteins may provide similar effects while alleviating concerns for oncogenicity. Thus, in the current proposal we plan to test the hypothesis that intradermal delivery of a DNA vaccine encoding HPV-16 E6 in conjunction with siRNA targeting key pro-apoptotic proteins to antigen-expressing dendritic cells would prolong transfected DC life and lead to enhanced E6-specific T cell-mediated immune responses and antitumor effects in vivo.