VSV-based Therapeutic Papilloma Vaccine

描述（由申请人提供）：宫颈的人乳头瘤病毒（HPV）感染引发宫颈癌的发展。接种疫苗有可能通过预防原发性HPV感染和消除持续性病变来预防宫颈癌。理想的疫苗将诱导治疗性和保护性免疫。治疗性疫苗开发的最佳动物模型是棉尾兔乳头瘤病毒（CRPV）-兔模型。表达外源病毒蛋白的活重组水泡性口炎病毒（rVSV）已成功地保护动物免受几种人类病毒的攻击。我们最近产生了一个表达CRPV E6肿瘤抗原的rVSV载体，并在初步实验中用它接种具有良好肿瘤（乳头状瘤）的兔子。该治疗诱导了显著的治疗结果，包括在一些兔中所有疾病的完全和永久性消退，总乳头状瘤负荷为4 cm 3，而对照组中没有消退。本申请的假设是，rVSV-E6疫苗可以被改进以诱导更快速和更普遍的消退。这是基于以下观察结果：原始疫苗表达的E6蛋白水平相对较低，并且由于初次接种诱导了VSV特异性中和抗体，因此使用相同的rVSV-E6再次接种可能无效。rVSV-E6的功效也可以通过修饰E6基因以编码遍在蛋白-E6融合蛋白（UbE 6）来提高，基于我们使用CRPV DNA疫苗的发现，UbE 6融合基因比未融合的E6基因明显更有效。具体目的是用更大的组大小和所有适当的对照重复初步实验;以确定使用提供更高水平E6表达或表达UbE 6的VSV载体、使用具有来自异源血清型的VSV包膜基因的有效VSV-E6加强载体或使用完全异源的病毒载体（腺病毒）是否可以获得更快速和更普遍的肿瘤清除。我们将确定最有效的治疗性疫苗是否也能诱导保护性免疫。这项研究提供的数据可能有助于开发一种高效的HPV疫苗，以保护妇女免受宫颈癌的侵害。

DESCRIPTION (provided by applicant): Human papillomavirus (HPV) infection of the cervix initiates the development of cervical cancer. Vaccination has the potential to prevent cervical cancer by preventing primary HPV infection and by eliminating persistent lesions. The ideal vaccine would induce therapeutic as well as protective immunity. The best animal model for therapeutic vaccine development is the cottontail rabbit papillomavirus (CRPV)-rabbit model. Live recombinant vesicular stomatitis viruses (rVSV) expressing foreign viral proteins have successfully protected animals against challenges with several human viruses. We recently generated an rVSV vector expressing the CRPV E6 tumor antigen and used it to vaccinate rabbits with well-established tumors (papillomas) in a preliminary experiment. The treatment induced dramatic therapeutic outcomes including the complete and permanent regression of all disease in some rabbits with a total papilloma burden of 4 cm3, as compared to no regression in the controls. The hypothesis of this application is that the rVSV-E6 vaccine can be improved to induce more rapid and more universal regression. It is based on the observation that the original vaccine expressed a relatively low level of E6 protein and that revaccination with the same rVSV-E6 was probably not effective, due to VSV-specific neutralizing antibodies induced by primary vaccination. The efficacy of the rVSV-E6 could also be improved by modifying the E6 gene to encode a ubiquitin-E6 fusion protein (UbE6), based on our findings, using CRPV DNA vaccines, that a UbE6 fused gene was markedly more effective than the unfused E6 gene. The specific aims are to repeat the preliminary experiment with larger group size and all appropriate controls; to determine if more rapid and more universal tumor clearance can be obtained using VSV vectors giving higher-level expression of E6 or expressing UbE6, using an efficient VSV-E6 boosting vector with the VSV envelope gene from a heterologous serotype, or using a completely heterologous viral vector (adenovirus). We will determine if the most effective therapeutic vaccine also induces protective immunity. The data provided by this investigation are likely to aid in the development a highly effective HPV vaccine to protect women against cervical cancer.