CORRELATES OF EFFICACY OF VEE-BASED SIV VACCINES

项目3的目标是阐明免疫效果与免疫效果的相关性，该疫苗来自优雅的委内瑞拉马脑炎(VEE)病毒复制子系统(SIV-VRP)。我们之前的研究表明，用来自委内瑞拉马脑炎(VEE)病毒复制子系统(SIV-VRP)的SIV疫苗免疫的猕猴，比模拟免疫的猕猴控制SIV静脉注射攻击的复制要好得多。在攻毒前，在PBMC批量培养中很容易检测到SIV特异性CD8+CTL，但缺乏抗攻毒病毒的血清中和抗体。因此，SIV-VRP免疫猕猴攻击后对SIV复制的有效控制是由于疫苗诱导了病毒特异性CTL。为了进一步探索这一假设，我们建议检查第一代和下一代SIV-VRP疫苗免疫猕猴的免疫效果相关性。首先，我们将确定第一代SIV-VRP疫苗中负责体内SIV复制的攻击后控制的病毒免疫原(S)，并表征与疗效相关的体液和细胞免疫反应。此外，我们将在“越多越好”的前提下，测试含有额外CTL表位的SIV-VRP疫苗(在GAG和POL中)。其次，我们将评估SIV-VRP免疫猕猴血清阻断或抑制SIV复制的能力，方法是采用“体内”中和试验。第三，我们将测试一种优化的SIV-VRP疫苗与纯化的Env亚单位增强相结合。本实验的目的是评估中和抗体在疫苗效力中的作用。两条挑战路线(i.v和i.r)将会被使用。最后，我们将结合所有3个HIV-RAD项目的技术和结果来生成最优的SIV-VRP疫苗策略，并将在SIV和SIV模型中进行测试。

The goal of Project 3 is to elucidate the immune correlates of efficacy in macaques immunized with SIV vaccines derived from the elegant Venezuelan Equine Encephalitis (VEE) virus replicon system (SIV-VRP). We previously showed that macaques immunized with an SIV vaccine derived from the Venezuelan Equine Encephalitis (VEE) virus replicon system (SIV-VRP) controlled replication of a virulent SIV intravenous challenge significantly better than mock immunized macaques. Prior to challenge, SIV-specific CD8+ CTL were easily detected in bulk cultures of PBMC, whereas serum neutralizing antibodies against the challenge virus were absent. Thus, it appeared that efficient control of SIV replication after challenge in SIV-VRP vaccinated macaques was due to vaccine elicited virus-specific CTL. To further explore this supposition, we propose to examine immune correlates of efficacy in macaques immunized with first and future generation SIV-VRP vaccines. First, we will determine which viral immunogen(s) in the first generation SIV-VRP vaccine was responsible for post-challenge control of in vivo SIV replication and characterize humoral and cellular immune responses associated with efficacy. Also, we will test SIV-VRP vaccines that contain additional CTL epitopes (in Gag and Pol) on the premise that "more is better." Second, we will assess sera from SIV- VRP immunized macaques for the ability to block or dampen SIV replication using an"in vivo" neutralization assay. Third, we will test an optimized SIV-VRP vaccine in combination with a purified Env subunit boost. The purpose of this experiment is to assess the role of neutralizing antibodies in vaccine efficacy. Two challenge routes (i.v and i.r.) will be used. Finally, we will combine technology and results from all 3 HIV- RAD Projects to generate the optimum SIV-VRP vaccine strategy, and this will be tested in both the SIV and SHIV models.