Novel Vaccine Strategies Against Ebola Virus

描述（由申请人提供）：这是一份修订后的项目申请，该项目的重点是开发预防埃博拉病毒（EBOV）引起的疾病的有效疫苗，埃博拉病毒是一种丝状病毒，是高致死性出血热的病原体。埃博拉病毒可以通过人与人之间的接触传播，因此构成了引起流行病爆发的高度威胁。我们的小组一直致力于针对病毒感染的VLP疫苗的开发，并且我们的结果已经表明，使用重组杆状病毒表达系统在昆虫细胞中产生的EBOV VLP（其产生高VLP产量）表现出DC刺激活性并诱导中和EBOV GP介导的病毒感染的强抗体应答（Ye等人，2006），表明此类VLP可用作安全有效的疫苗以诱导针对EBOV感染的保护性免疫。此外，我们还在最近的研究中发现，与单独使用DNA或VLP疫苗的免疫相比，使用DNA和VLP疫苗的混合物（DNA/VLP）的免疫诱导更高水平的抗体和细胞免疫应答。用这种新的疫苗策略获得的两种基于非病毒载体的疫苗平台的组合益处证明了其开发针对EBOV感染的有效疫苗的潜力。在这个项目中，我们将测试新的DNA/VLP疫苗策略将引发针对EBOV感染的强烈的细胞和抗体应答，并且佐剂的使用将进一步增强这种应答的诱导的假设，目的是获得可以赋予针对EBOV感染的快速以及持久的保护的疫苗策略。具体目标1。我们将比较DNA/VLP免疫与单独的DNA或VLP疫苗诱导的免疫应答，并确定DNA/VLP疫苗策略是否优于上级，以提供快速（减少接种次数）以及持久（接种后6个月）的针对EBOV感染的保护。此外，我们将采用转基因小鼠模型来研究DNA/VLP免疫诱导增强抗体和T细胞应答的潜在机制，这将为进一步开发针对EBOV以及其他病原体的更有效的疫苗提供指导信息。具体目标2。我们将研究佐剂对DNA/VLP疫苗接种的影响，并与单独的DNA或VLP疫苗接种进行比较，以确定是否可以获得一种有效的疫苗策略，通过单次免疫引起针对EBOV感染的保护性免疫。此外，我们将进一步研究DNA/VLP疫苗在豚鼠中的效力，以评估其在不同的小型实验室动物模型中抗EBOV感染的效力，目的是确定DNA/VLP疫苗策略在非人灵长类动物模型中用于未来评估的潜力。埃博拉病毒（Ebola virus，EBOV）是一种丝状病毒，是引起高致死性出血热的病原体。埃博拉病毒可以通过人与人之间的接触传播，因此构成了爆发流行病的高度威胁。我们先前已经显示了两种基于非病毒载体的疫苗平台的组合益处及其开发针对EBOV感染的有效疫苗的潜力。在这个项目中，我们将测试的假设，新的DNA/VLP疫苗策略将引起强烈的细胞和抗体反应，对EBOV感染，使用佐剂将进一步增强诱导这种反应。

DESCRIPTION (provided by applicant): This is a revised application for a project focused on development of an effective vaccine for prevention of disease caused by Ebola virus (EBOV), a filovirus which is an etiologic agent of highly lethal hemorrhagic fever. Ebola virus can be transmitted via person-to-person contact, thus posing a high threat of causing an epidemic outbreak. Our group has been engaged in the development of VLP vaccines against virus infection, and our results have shown that EBOV VLPs produced in insect cells using the recombinant baculovirus expression system, which gives high VLP production yield, exhibit DC-stimulating activity and induce strong antibody responses that neutralize EBOV GP mediated virus infection (Ye et al., 2006), indicating that such VLPs could serve as safe and effective vaccines to induce protective immunity against EBOV infection. Furthermore, we also made the finding in recent studies that immunization with a mixture of DNA and VLP vaccines (DNA/VLP) induced higher levels of both antibody and cellular immune responses in comparison to immunization with DNA or VLP vaccines alone. The combined benefit of two non-viral-vector based vaccine platforms obtained with this novel vaccine strategy demonstrates its potential for the development of an efficacious vaccine against EBOV infection. In this project, we will test the hypotheses that the novel DNA/VLP vaccine strategy will elicit strong cellular and antibody responses against EBOV infection and that the use of an adjuvant will further augment induction of such responses, with the aim to obtain a vaccine strategy that can confer rapid as well as long lasting protection against EBOV infection. Specific Aim 1. We will compare immune responses induced by DNA/VLP immunization with DNA or VLP vaccines alone and determine whether the DNA/VLP vaccine strategy is superior to confer rapid (with reduced number of vaccinations) as well as long lasting (at six months after vaccinations) protection against EBOV infection. Moreover, we will employ a transgenic mouse model to investigate the underlying mechanism for the induction of enhanced antibody and T cell responses by DNA/VLP immunization, which will provide instructive information for further development of more potent vaccines against EBOV as well as other pathogens. Specific Aim 2. We will investigate the effect of adjuvant on DNA/VLP vaccination in comparison with DNA or VLP vaccination alone, and determine whether a potent vaccine strategy can be obtained to elicit protective immunity against EBOV infection by a single immunization. Moreover, we will further investigate the efficacy of DNA/VLP vaccines in guinea pigs to assess their potency against EBOV infection in a different small laboratory animal model, with the aim to determine the potential of the DNA/VLP vaccine strategy for future evaluation in the non-human primate model. Ebola virus (EBOV) is a filovirus which is an etiologic agent of highly lethal hemorrhagic fever. Ebola virus can be transmitted via person-to-person contact, thus posing a high threat of an epidemic outbreak. We have previously shown the combined benefit of two non-viral-vector based vaccine platforms and its potential for the development of an efficacious vaccine against EBOV infection. In this project we will test the hypotheses that the novel DNA/VLP vaccine strategy will elicit strong cellular and antibody responses against EBOV infection and that the use of an adjuvant will further augment induction of such responses.