Therapeutic Vaccine for HIV/HPV-associated Oropharyngeal and Tonsillar Malignanci

描述(申请人提供)：本项目的目标是根据HPV在发病机制中的作用，开发一种治疗H|V相关恶性肿瘤的策略。HPV相关肿瘤表达HPV的E6/E7癌蛋白，是免疫诱导疫苗的理想靶点。我们将基于一种新型的腺病毒血清型-S载体(ADS)平台，通过唯一和额外的缺失病毒DNA聚合酶和早期基因2b(E2b)区的前末端蛋白(ADS[E1-，E2b-])来开发疫苗。在使用HIV抗原的研究中，我们报道了在多次免疫方案中，新的Ad5[E1-，E2b-]-HLV载体疫苗在诱导CMI反应时优于现有的AdS[E1-]-H|V载体疫苗(包含早期基因1(E1)区的缺失)。尽管存在预先存在的ADS免疫，但在小鼠和猴子中诱导了显著的抗原特异性CMI反应。我们将构建和生产含有具有非致癌功能的HPV癌蛋白E6/E7的AdS[E1-，E2b-]载体疫苗。这种新的重组腺病毒将通过表达修饰的HPV-E6/E7抗原，在直接转染抗原提呈细胞后诱导免疫应答。我们将结合一种Toll样受体激动剂(TLRa)进行评估，该药物旨在增强疫苗诱导的免疫反应。我们的临床前数据表明，即使在存在预先存在的ADS免疫的情况下，ADS[E1-，E2b-]VEC*或诱导针对肿瘤相关抗原[FAA]的强大CMI反应。在采用癌胚抗原(CEA)基因插入的小鼠肿瘤模型中，比较了新AdS[E1-，E2b-L-GEA]与新一代AdS TE1-L-CEA重复免疫的免疫原性和体内抗肿瘤效果。这些ADS载体在临床相关的ADS免疫环境中进行了测试。我们观察到，用ADS[E1-，E2b-]-CEA多次免疫的ADS免疫小鼠诱导的CEA特异性CMI反应显著高于用当代ADS TE1-L-CEA多次免疫的ADS免疫小鼠。ADS免疫的携带CEA表达肿瘤的小鼠经ADS[E1-，E2b-J-CEA]治疗后的抗肿瘤反应比ADS[E1-I-CEA]治疗的小鼠增强。这些结果表明，即使存在预先存在的ADS免疫，ADS[E1-，EZB-L-CEA]仍能诱导CMI免疫反应，导致肿瘤生长抑制。我们还利用表达TAA HER2lneu的ADS[E1-，EZB-]载体平台作为乳腺癌免疫治疗剂。AdS[E1b-，E2b-L-HERZlneu]可诱导抗HER2/neu的强大CMI，并显著抑制Ad5免疫小鼠已建立的肿瘤的进展。这些结果表明，体内表达TM的Ad5[E1-，E2b-]载体可以诱导抗TAA免疫，抑制ADS免疫动物的肿瘤进展。 公共卫生意义：在这项研究中，我们将开发一种新腺病毒药物(ADS[E1-，E2b-I-HPV-E6/7])来治疗HPV相关性口咽和扁桃体癌患者。需要治疗平台来克服预先存在的ADS免疫力，这种免疫力阻止了这类技术的广泛使用。

DESCRIPTION (provided by applicant): The objective of this project is to develop a therapeutic strategy for H|V-associated malignancy based on the role of HPV in the pathogenesis. HPV related cancers express the E6/E7 oncoproteins of HPV that are ideal targets for immune inducing vaccines. We will develop a vaccine based upon a novel adenovirus serotype-S vector (Ads) platform with unique and additional deletions of the viral DNA polymerase and the pre- terminal protein in the early gene 2b (E2b) region (Ads [E1-, E2b-]). In studies employing HIV antigens, we reported that the new Ad5 [E1-, E2b-]-HlV vector vaccine was superior to a current Ads [E1-]-H|V vector vaccine (containing deletion in the early gene 1 (E1) region) when used to induce CMI responses in a multiple immunization regimen. Significant antigen specific CMI responses were induced in mice and monkeys despite the presence of pre-existing AdS immunity. We will construct and produce an AdS [E1-, E2b-] vector vaccine that contains the HPV oncoproteins E6/E7 with non-oncogenic function. This new recombinant adenovirus will induce immune responses by expressing the modified HPV-E6/E7 antigens after direct transfection of antigen presenting cells. We will evaluate this in combination with a toll-like receptor agonist (TLRa) designed to enhance immune responses induced by the vaccine. Our pre-clinical data indicate that the AdS [E1-, E2b-] vec*or induces robust CMI responses against tumor associated antigen [fAA), even in the presence of pre- existing AdS immunity. In a murine cancer model employing the carcinoembryonic antigen (CEA) gene insert, tl.g -CEA immunogenicity and in vivo anti-tumor effects of repeated immunizations with i new AdS [E1-, E2b-l- GEA were compared to those observed with a current generation Ads tE1-l-CEA. These AdS vectors were tested in a clinically relevant AdS immune setting. We observed that AdS immune mice immunized multiple times with AdS [E1-, E2b-]-CEA induced CEA-specific CMI responses that were significantly increased over those detected in AdS immune mice immunized multiple times with a current generation AdS tE1-l-CEA. Ads immune mice bearing CEA expressing tumors that were treated with AdS [E1-, E2b-J-CEA had an increased anti-tumor response as compared to AdS [E1-I-CEA treated mice. These results demonstrate that AdS [E1-, Ezb-l-CEA can induce CMI immune responses that result in tumor growth inhibition despite the presence of pre-existing AdS immunity. We have also utilized the Ads [E1-, Ezb-] vector platform expressing the TAA HER2lneu as a breast cancer immunotherapeutic agent. Ads [E1-, E2b-l-HERZlneu induced potent CMI against HER2/neu and significantly inhibited progression of established tumors in Ad5 immune mice. These data demonstrate that in vivo delivery of Ad5 [E1-, E2b-] vectors expressing TM can induce anti-TAA immunity and inhibit progression of tumors in AdS immune animals. PUBLIC HEALTH RELEVANCE: In this study, we will develop a new adenoviral based drug (AdS [E1-, E2b-I-HPV-E6/7) to treat HtV+ patients with HPv-associated oropharyngeal and tonsillar ,ncers. The treatment platform is needed to overcome pre-existing AdS immunity that has prevented the widespread use of this type of technology.