Vaccination with self-launching RhCMV/SIV DNA vaccine vectors

项目摘要/ABSRACT 一种预防性的艾滋病毒疫苗将有助于减少对全球健康的影响 感染人数。同样，需要新的疫苗方法，有可能 减少结核病和疟疾的发病率。携带RhCMV的SIV疫苗已经证明 激发免疫反应控制SIV感染的巨大潜力，但不稳定 CMV基因组和疫苗库存中相对较大比例的非传染性病毒粒子 主要的实践挑战，这些挑战已经推迟了CMV载体疫苗在人类身上的测试 病人。此外，在一些艾滋病毒流行地区，对冷链的需求可能是不可行的 这是个问题。在这里，我们描述并建议测试基于CMV递送的疫苗平台- 基于核酸形式的疫苗载体基因组。我们已经证明，交付的基因组是 能够在体内启动自我维持的复制，并且这种载体复制产生 免疫反应至少与(常规)刺激的免疫反应相当(如果不是更好的话 用封装的疫苗载体颗粒接种疫苗。顺利完成本R21项目 因此将加快基于CMV的艾滋病毒疫苗的开发，并可能像 井。事实上，我们认为，在CMV载体疫苗能够 对人类健康产生了该领域所希望的积极影响。这项工作的目标是 为巨细胞病毒疫苗的体内投放提供一个实用、经济高效的平台。我们的 假设RhCMVdIL10-SIVgag和-SIVenv疫苗作为复制能力， 自切BAC DNA可诱导具有独特特征的免疫反应 以RhCMV为载体的疫苗接种，对SIV具有保护作用。这一假设将会得到解决。 在两个具体目标上使用了恒河猴非人类灵长类动物模型。目标1将决定 复制和传播以及宿主免疫的最佳体内递送方法 对一种新型的自行启动的RhCMVdIL10-SIV疫苗的反应。三种不同的体内实验方法 BAC DNA的运送将进行免疫原性测试。细胞和体液免疫反应， 包括MAMU-E限制性反应的发展，除复制外，还将进行评估 以及媒介的传播。AIM 2将测试RhCMVdIL10-SIVgag和-SIVenv疫苗是否 当作为自动发射的BAC提供时，可防止SIV疾病。我们将确定其程度 在接种猕猴疫苗后，对低剂量、致病性SIV挑战的保护作用 使用目标1中确定的最佳递送方法。 这一提议将解决目前限制基于CMV的开发的许多障碍 病毒载体，并对影响人类健康的其他疾病具有广泛的适用性。

PROJECT SUMMARY/ABSRACT A prophylactic HIV vaccine would be of tremendous benefit for global health by helping to reduce the number of infected people. Similarly, new vaccine approaches are needed with the potential to reduce incidence of tuberculosis and malaria. RhCMV-vectored SIV vaccines have demonstrated tremendous potential for eliciting immune responses that can control SIV infection, but the unstable CMV genome and the relatively large proportion of non-infectious virions in vaccine stocks present major practical challenges, which have already delayed tests of CMV-vectored vaccines in human patients. Additionally, the need for a cold chain that is likely infeasible in some HIV-endemic areas is problematic. Here we describe and propose to test a vaccine platform based on delivery of the CMV- based vaccine vector genome in nucleic-acid form. We have shown that the delivered genomes are capable of initiating self-sustaining replication in vivo, and that this vector replication engenders immune responses that appear at least equal if not superior to those stimulated by (conventional) vaccination with encapsidated vaccine-vector particles. Successful completion of this R21 project will thus accelerate CMV-based vaccine development for HIV and potentially other diseases as well. Indeed, we believe that an advance such as this is required before CMV-vectored vaccines can have the positive impact on human health that is so hoped for by the field. The goal of this work is to provide a practical, cost-effective platform for cytomegalovirus-based vaccine delivery in vivo. Our hypothesis is that RhCMVdIL10-SIVgag and -SIVenv vaccines delivered as replication-competent, self-excising BAC DNA can elicit immune responses that have the unique character associated with RhCMV-vectored vaccination and that are protective against SIV. This hypothesis will be addressed in two specific aims using the rhesus macaque non-human primate model. Aim 1 will determine the optimal in vivo delivery method for replication and dissemination of, as well as host immune responses to, a novel, self-launching RhCMVdIL10-SIV vaccine. Three different methods of in vivo BAC DNA delivery will be tested for immunogenicity. Cellular and humoral immune responses, including the development of Mamu-E-restricted responses, will be assessed in addition to replication and dissemination of the vector. Aim 2 will test if RhCMVdIL10-SIVgag and -SIVenv vaccines are protective against SIV disease when delivered as self-launching BACs. We will determine the extent of protection achieved against low-dose, pathogenic SIV challenge following vaccination of macaques using the optimal delivery method identified in Aim 1. The novel vaccine vectors that are described in this proposal will solve many of the hurdles that are limiting the development of current CMV-based viral vectors and have broad applicability for other diseases that impact human health.