Second Generation Rabies Vaccines

描述（由申请人提供）：狂犬病是一个主要的全球健康问题，每年造成约4万至7万人死亡，超过1000万人在接触可能受感染的动物后接受暴露后预防（PEP）。成本和合规问题极大地阻碍了现有疫苗的有效性。使这一问题更加复杂的是，目前的疫苗不能有效预防几种新发现的狂犬病相关病毒引起的疾病。此外，最近在许多被认为含有灭活狂犬病病毒的疫苗中发现了活病毒。总之，开发新型暴露前和暴露后疫苗对于解决这一全球健康问题是必要的。由于暴露前疫苗接种仅针对实验室工作人员和兽医等高危人群，因此PEP是预防人类狂犬病的全球标准。因此，开发可替代的pep是这个应用程序的目标。目前的pep包括一剂被动免疫（狂犬病免疫球蛋白）和五剂主动免疫（狂犬病疫苗）。我们假设有复制缺陷的RVs会产生优秀的狂犬病pep。它们能够诱导强大的先天和适应性免疫反应，本质上是安全的，可以生长到高升。提出了两个具体目标：首先，构建具有复制缺陷的rna载体，删除P或M基因。P或m缺失的RV表达两个相同的RV G拷贝也将被构建，从而诱导细胞凋亡并增强抗RV免疫反应。我们将描述这些新的病毒载体在体外的遗传稳定性、生长动力学和转基因表达。其次，使PEP可行的RV感染的一个标志是暴露在外周部位的时间与RV感染中枢神经系统的时间之间的相对较长时间。因此，成功的PEP绝对需要快速的体液反应。我们将利用这些新载体研究小鼠诱导免疫反应的动力学。RV G蛋白elisa、病毒中和试验和流式细胞术分析将用于研究诱导的体液反应。t辅助反应对于强b细胞反应很重要，将通过对RV G和n的增殖试验来评估。最有希望的载体将在定义明确的叙利亚仓鼠模型中进行测试，以确定感染致病性RV菌株后是否提供保护。这些反应将与一种获得许可的灭活狂犬病疫苗进行比较。本应用程序的目的是开发安全有效的替代目前的人类狂犬病暴露后预防。只需要一到两剂疫苗而不是六剂疫苗的治疗方法的发展将大大提高狂犬病病毒预防的有效性。

DESCRIPTION (provided by applicant): Rabies is a major global health issue that kills approximately 40,000 to 70,000 people per year and over 10 million people receive post-exposure prophylaxis (PEP) after exposure to potentially infected animals. Cost and compliance issues have greatly hampered the effectiveness of current vaccines. To confound this issue, current vaccines are not effective at preventing disease from several newly identified rabies related viruses. In addition, live virus was recently discovered in a lot of vaccine that was supposed to contain inactivated rabies virus. Taken together, the development of novel pre- and post-exposure vaccines is necessary to combat this global health issue. Since pre-exposure vaccination is reserved only for those at-risk populations, such as laboratory workers and veterinarians, PEP is the world-wide standard for human rabies prevention. As such, the development of alternative PEPs is the goal of this application. Current PEPs are comprised of one dose of passive immunization (rabies immune globulin) along with five active immunizations with rabies vaccines. We hypothesize that replication-deficient RVs will make excellent rabies PEPs. They are able to induce potent innate and adaptive immune responses, are intrinsically safe and can be grown to high liters. Two specific Aims are proposed: First, replication-deficient RV-based vectors will be constructed that have either P or M genes deleted. P- or M-deleted RVs that express two identical copies of RV G will also be constructed, which induces apoptosis and enhances anti-RV immune responses. We will characterize the genetic stability, growth kinetics, and transgene expression of these new viral vectors in vitro. Second, a hallmark of RV infection that makes PEP feasible is the relatively long period between the time of exposure at the peripheral site and the time when RV infects the central nervous system. As such, a rapid humoral response is absolutely required for a successful PEP. We will investigate the kinetics of the induced immune response in mice using these new vectors. RV G protein ELISAs, virus neutralization assays, and flow cytometry analysis will be used to study the induced humoral response. T-helper responses, which are important for strong B-cell responses, will be evaluated by proliferation assays against RV G and N. The most promising vectors will be tested in a well-defined Syrian hamster model to determine whether protection is provided after infection with a pathogenic RV strain. The responses will be compared with a licensed inactivated rabies vaccine. The goal of this application is to develop safe and effective alternatives to the current human rabies post- exposure prophylaxis. The development of treatment that relies on only one to two doses of vaccine instead of six inoculations will greatly enhance the effectiveness of rabies virus prevention.