CORRELATES OF EFFICACY OF VEE-BASED SIV VACCINES

项目3的目标是阐明用委内瑞拉马脑炎（VEE）病毒复制子系统（SIV- vrp）衍生的SIV疫苗免疫猕猴的有效性的免疫相关因素。我们之前的研究表明，接种了委内瑞拉马脑炎（VEE）病毒复制子系统（SIV- vrp）衍生的SIV疫苗的猕猴对SIV静脉攻击的复制控制明显优于模拟免疫的猕猴。在攻毒之前，在PBMC的散装培养中很容易检测到siv特异性CD8+ CTL，而血清中没有针对攻毒病毒的中和抗体。因此，SIV- vrp疫苗接种猕猴攻击后SIV复制的有效控制似乎是由于疫苗引发的病毒特异性CTL。为了进一步探索这一假设，我们建议在接种了第一代和下一代SIV-VRP疫苗的猕猴中检测其有效性的免疫相关因素。首先，我们将确定第一代SIV- vrp疫苗中的哪种病毒免疫原负责攻击后体内SIV复制的控制，并表征与有效性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（Gag和Pol）的SIV-VRP疫苗。其次，我们将使用“体内”中和试验评估SIV- VRP免疫猕猴血清阻断或抑制SIV复制的能力。第三，我们将测试一种优化的SIV-VRP疫苗与纯化的Env亚单位增强剂联合使用。本实验的目的是评估中和抗体在疫苗效力中的作用。将采用两种挑战途径（静脉注射和静脉注射）。最后，我们将结合所有3个HIV- RAD项目的技术和结果，以产生最佳的SIV- vrp疫苗策略，并将在SIV和SHIV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.