Genital Herpes Vaccine Discovery

描述（由申请方提供）：本项目的主要目的是使用新型疫苗平台技术（VesiVax（r）系统）开发一种安全的HSV 2疫苗，该疫苗能够在男性和女性人群中提供比其他重组疫苗更好的保护水平。我们已经证明，靶向gD包膜蛋白单表位的HSV 2 VesiVax（r）疫苗能够保护雌性和雄性小鼠免受粘膜HSV 2攻击（分别为阴道内和直肠内），存活率增加，感染的临床体征显著减少，并且进一步积极刺激两性中有效的T细胞免疫应答。在I期研究中，我们证明了对应于整个HSV 2 gD胞外域（氨基酸1-306）的抗原片段在致死HSV 2攻击的阴道内（雌性）和直肠内（雄性和雌性）小鼠模型中提供了疾病保护，在豚鼠模型中具有显著降低原发性疾病和降低复发性感染的趋势。我们现在建议采用我们的主要候选疫苗L-HSV 2gD 1 -306-HD，并将其推向临床评估。为了实现这一目标，需要完成一些技术目标。我们的第一步将是确定最佳抗原剂量和时间表以及不同的施用途径（即，皮下或肌内），这是在用致死剂量的HSV 2阴道内或直肠内攻击的雄性和雌性小鼠中进行有效免疫所需的。L-HSV 2gD 1 -306-HD疫苗将通过以下方式进行进一步检测：按照小鼠研究确定的最佳给药方案和给药途径，以增加的抗原剂量免疫雄性和雌性豚鼠，然后用HSV 2攻毒动物，以确定其对原发性和复发性感染的应答。我们还将使用优化的疫苗接种参数表征雄性和雌性小鼠对L-HSV 2gD 1 -306-HD疫苗构建体的免疫应答。同时，通过优化研究，我们将重点开发生产临床级L-HSV 2gD 1 -306-HD疫苗批次的工艺。我们的第一批活动将是建立一个开发细胞库。然后，我们将从开发细胞库中制备主细胞库和工作细胞库，并对其进行表征。然后，我们将使用适合规模化的标准设备通过发酵来优化HSV 2gD 1 -306-HD生产工艺。分离和纯化HSV 2gD 1 -306-HD蛋白的工艺将基于现有方法的改良，并将开发更大规模生产L-HSV 2gD 1 -306-HD疫苗的工艺条件。我们还将开发确保L-HSV 2gD 1 -306-HD各制剂质量所需的分析方法。使用这些试验，将评价HSV 2gD 1 -306-HD批次的强制降解试验。使用这些试验，将在不同条件下监测L-HSV 2gD 1 -306-HD批次（即，温度，pH）进行强制降解试验。使用这些程序，L-HSV 2gD 1 -306-HD疫苗将按照FDA现行药品生产质量管理规范（cGMP）法规扩大规模并生产中试批次材料。L-HSV 2gD 1 -306-HD中试批次的制备量应足以进行稳定性和等效性试验以及最终的安全性和免疫原性研究。对于稳定性研究，将L-HSV 2gD 1 -306-HD小瓶储存在选定的储存温度下，并定期分析产品的变化。最后，将在用于开发L-HSV 2gD 1 -306-HD疫苗的HSV 2感染雄性和雌性小鼠模型中检测中试批次材料。将中试材料与实验室制备的材料在用致死剂量的HSV 2攻毒后的存活率和疾病体征减少方面进行比较。还将在用于开发L-HSV 2gD 1 -306-HD疫苗的复发性HSV 2感染的雄性和雌性豚鼠模型中检测中试批次的材料。在感染剂量的HSV 2攻毒后原发感染减少和疱疹病变无复发方面，将中试材料与实验室制备的材料进行比较。公共卫生相关性：这项SBIR研究将导致一种新型生殖器疱疹疫苗的开发和生产，该疫苗在生产经济性和免疫活性方面具有显着优势，可用于未来预防HSV 2传播的临床应用。

DESCRIPTION (provided by applicant): The primary objective of this project is to develop, using a novel vaccine platform technology (the VesiVax(r) system), a safe HSV2 vaccine that is capable of providing a level of protection in male and female human populations which is better than other recombinant vaccines. We have shown that HSV2 VesiVax(r) vaccines targeted to single epitopes from the gD envelope protein are capable of protecting both female and male mice from mucosal HSV2 challenge (intravaginal and intrarectal, respectively) with increased survival and markedly reduced clinical signs of infection and further, actively stimulates effective T-cell immune responses in both sexes. In the Phase I studies, we demonstrated that an antigenic segment corresponding to the entire HSV2 gD ectodomain (amino acids 1-306) provided protection from disease in both intravaginal (female) and intrarectal (male and female) mouse models of lethal HSV2 challenge with a significant reduction in primary disease and a trend towards reducing recurrent infections in a guinea pig model. We now propose to take our lead vaccine candidate, L-HSV2gD1-306-HD, and move it towards clinical evaluation. To accomplish this objective, a number of technical objectives will need to be completed. Our first step will be to determine the optimal antigen dose and schedule as well as different routes of administration (i.e., subcutaneous or intramuscular) required for effective immunization in male and female mice challenged intravaginally or intrarectally with a lethal dose of HSV2. The L-HSV2gD1-306-HD vaccine will undergo further testing by immunizing male and female guinea pigs with increasing antigen doses at the optimal dosing schedule and route of administration determined from the mouse studies and then challenging the animals with HSV2 to determine their response to primary and recurrent infection. We will also characterize the immunological response of the male and female mice to the L-HSV2gD1-306-HD vaccine construct using the optimized vaccination parameters. Concurrently, with the optimization studies, we will focus on developing the processes for manufacturing clinical grade batches of the L-HSV2gD1-306-HD vaccine. Our first activities will be directed towards producing a Development Cell Bank. We will then prepare a Master Cell Bank and Working Cell Bank from the Development Cell Bank and characterize them. We will then optimize the HSV2gD1-306-HD production process by fermentation using standard equipment that is amenable to scale-up. The processes for isolating and purifying the HSV2gD1-306-HD protein will be based on modifications of existing methods and the development of the processing conditions to produce the L-HSV2gD1-306-HD vaccine in larger scale will be performed. We will also develop the analytical methods required for ensuring the quality of each preparation of L-HSV2gD1-306-HD. Using these assays, batches of HSV2gD1-306-HD will be evaluated for stress testing. Using these assays, batches of L-HSV2gD1-306-HD will be monitored under different conditions (i.e., temperature, pH) for stress testing. Using these procedures, the L-HSV2gD1-306-HD vaccine will be scaled-up and pilot batches of material produced in conformance to FDA current Good Manufacturing Practice (cGMP) regulations. The pilot batches of L-HSV2gD1-306-HD will be prepared in sufficient amounts to allow for stability and equivalency testing, and eventual safety and immunogenicity studies. For the stability studies, vials of L- HSV2gD1-306-HD will be stored at selected storage temperatures and analyzed periodically for changes in the product. Lastly, the pilot batches of material will be tested in the male and female mouse models of HSV2 infection that have been used to develop the L-HSV2gD1-306-HD vaccine. The pilot material will be compared against laboratory prepared material in terms of survival and reduction of the signs of disease following challenge with a lethal dose of HSV2. The pilot batches of material will also be tested in the male and female guinea pig models of recurrent HSV2 infection that have been used to develop the L-HSV2gD1-306-HD vaccine. The pilot material will be compared against laboratory prepared material in terms of reduction of the primary infection following challenge with an infectious dose of HSV2 and the lack of recurrence of herpetic lesions. PUBLIC HEALTH RELEVANCE: This SBIR research will lead to the development and production of a novel genital herpes vaccine having significant advantages in production economy and immunological activity for future clinical use in preventing the spread of HSV2.