Genital Herpes Vaccine Discovery

描述(由申请人提供)：该项目的主要目标是利用一种新的疫苗平台技术(VesiVax(R)系统)开发一种安全的HSV2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，针对gD包膜蛋白单一表位的HSV2 VesiVax(R)疫苗能够保护雌性和雄性小鼠免受HSV2粘膜攻击(分别是阴道内和直肠内)，并提高存活率，显著减少临床感染迹象，进一步积极刺激有效的T细胞免疫反应。在第一阶段的研究中，我们证明了对应于整个HSV2 gD胞外区(氨基酸1-306)的抗原片段在阴道内(雌性)和直肠内(雄性和雌性)小鼠模型中都提供了疾病保护，在豚鼠模型中显著减少了原发病，并有减少反复感染的趋势。我们现在建议采用我们的主要候选疫苗L-HSV2gD1-306-HD，并将其用于临床评估。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的抗原剂量和程序以及有效免疫所需的不同给药途径(即皮下或肌肉内)，对阴道内或直肠内感染致死量HSV2的雄性和雌性小鼠进行有效免疫。L-HSV2gD1-306-HD疫苗将接受进一步的测试，按照小鼠研究确定的最佳给药程序和途径，增加抗原剂量免疫雄性和雌性豚鼠，然后用HSV2攻击动物，以确定它们对初次和反复感染的反应。我们还将利用优化的免疫参数来表征雄性和雌性小鼠对L-HSV2gD-306-HD疫苗构建的免疫应答。同时，在优化研究的同时，重点开发L-HSV2gD-306-HD疫苗临床级批次的生产工艺。我们的第一批活动将针对建立一个发展细胞库。然后，我们将从发育细胞库中准备一个主细胞库和工作细胞库，并对它们进行表征。然后，我们将使用可放大的标准设备，通过发酵来优化HSV2gD1-306-HD的生产工艺。HSV2gD1-306-HD蛋白的分离和纯化将在改进现有方法的基础上进行，并将开发工艺条件，以更大规模地生产HSV2gD1-306-HD疫苗。我们还将制定确保L-HSV2gD1-306-HD各制剂质量所需的分析方法。使用这些检测方法，将对一批HSV2gD1-306-HD进行压力测试评估。利用这些检测方法，将在不同条件(即温度、pH)下对L-HSV2gD1-306-HD批次进行监测，以进行压力测试。使用这些程序，L-HSV2gD1-306-HD疫苗将被放大并试生产符合FDA现行良好生产规范(CGMP)规定的材料。将制备足够数量的L-HSV2gD1-306-HD中试批次，以便进行稳定性和等效性测试，以及最终的安全性和免疫原性研究。在稳定性研究中，L-HSV2gD1-306-HD将在选定的储存温度下储存，并定期分析产品的变化。最后，试验批次的材料将在感染单纯疱疹病毒2型的雄性和雌性小鼠模型上进行测试，这些模型已经被用于开发L-HSV2gD1-306-HD疫苗。试验材料将与实验室准备的材料在用致死剂量的HSV2攻击后的存活率和疾病迹象的减少方面进行比较。试点批次的材料还将在反复感染HSV2的雄性和雌性豚鼠模型中进行测试，这些模型已被用于开发L-HSV2gD1-306-HD疫苗。试验材料将与实验室准备的材料进行比较，以减少在感染剂量HSV2后的初次感染和无疱疹皮损的复发。公共卫生相关性：这项SBIR研究将导致开发和生产一种在生产、经济和免疫活性方面具有显着优势的新型生殖器疱疹疫苗，用于未来临床预防HSV2的传播。

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.