Focused characterization of non-canonical T cells against SIV

摘要 根据我们目前掌握的信息，一种完全预防艾滋病毒感染的疫苗， 一部分接种疫苗的人似乎遥不可及。一种更现实的疫苗将是一种钝化 急性病毒血症，更重要的是，长期维持对病毒的免疫抑制 没有抗逆转录病毒药物的帮助。这样的疫苗应该会引起有效的T细胞反应。CMV矢量化 SIV疫苗重新燃起了研制这种疫苗的希望。成功的一个关键 CMV载体疫苗是其引发和维持针对SIV的CD 8 T细胞应答的显著能力， 以非规范的方式限制，特异性靶向SIV衍生的表位，这些表位存在于 MHC-II和MHC-E分子的背景。然而，目前尚不清楚CMV载体疫苗是否 可以直接转化为艾滋病毒。因此，迫切需要更多的候选疫苗， 这样就可以进行基本的机制实验，以了解其他疫苗平台如何 可以诱导类似有效的CD 8 T细胞应答。为此，我们研究了一部小说， 在Env胞质结构域中仅缺少两个氨基酸的SIV减毒突变体。这种病毒被称为 抗戈伊，诱导有效的T细胞反应，沿着无中和抗体，并保护猪尾猕猴 来自多种同源和异源致病性SIV。值得注意的是，我们的初步数据显示， 像CMV一样，激发非典型的CD 8 T细胞应答，其在体外可以靶向并消除病毒感染的靶点 细胞在这里，我们建议利用这一现象，开始梳理这些反应。为此我们 我将使用南非食蟹猴（MCM），这与辫子形成鲜明对比， 由于岛上的人口瓶颈，MHC遗传学。在目标1中，我们将给MCM接种抗戈伊疫苗， 全面表征CD 8 T细胞应答，重点关注交替限制性T细胞，包括 确定它们的分子限制。在目标2中，我们将评估这些应对措施是否能保护这一点。 种猕猴从致病性SIVsmE 660。我们还将在体外扩增T细胞系和克隆， 接种疫苗的动物，并确定它们在体外消除各种致病性攻击病毒的能力。 总之，这种高度集中的实验设计将使我们开始解剖非典型的CD 8 T细胞， 它们的限制性分子，以及它们抵御各种病毒的能力。我们希望这些数据能够 更大的项目旨在破译机制，也许与CMV共享，导致这些高度 有效的交替CD 8 T细胞应答。

Abstract With the information we currently have available, a vaccine that prevents HIV infection outright in a substantial portion of vaccinated individuals seems out of reach. A far more realistic vaccine would be one that blunts acute viremia and, more importantly, maintains immunologic suppression of the virus for long periods of time without the aid of antiretroviral drugs. Such a vaccine should elicit potent T cell responses. The CMV vectored SIV vaccine has reinvigorated hopes that such a vaccine could be possible. One key to the success of the CMV vectored vaccine is its remarkable ability to prime and maintain CD8 T cell responses against SIV that are restricted in non-canonical fashion, specifically targeting SIV derived epitopes that are presented in the context of MHC-II and MHC-E molecules. However, it’s not clear at this time that the CMV vectored vaccine can be directly translated to HIV. Thus, more vaccine candidates are sorely needed that induce similar responses so that basic mechanistic experiments can be conducted to understand how other vaccine platforms can be made to induce similarly effective CD8 T cell responses. To this end, we have investigated a novel attenuated mutant of SIV that lacks just two amino acids in the Env cytoplasmic domain. This virus, termed ∆GY, induces potent T cell responses along with no neutralizing antibodies, and protects pigtail macaques from multiple homologous and heterologous pathogenic SIVs. Remarkably, our preliminary data suggest ∆GY, like CMV, elicits non-canonical CD8 T cell responses that, in vitro, can target and eliminate virus infected target cells. Here, we propose to capitalize on this phenomenon to begin to tease out these responses. To do this, we will use Mauritian cynomolgus macaques (MCM), which, in stark contrast to pigtails, exhibit remarkably simple MHC genetics due to a population bottleneck on the island. In Aim 1, we will vaccinate MCM with ∆GY and comprehensively characterize the CD8 T cell response with focus on alternately restricted T cells, including determining their molecular restriction. In Aim 2, we will assess whether these responses can protect this species of macaque from pathogenic SIVsmE660. We will also expand T cell lines and clones in vitro from the vaccinated animals and determine their capacity to eliminate diverse pathogenic challenge viruses in vitro. Together, this highly focused experimental design will allow us to begin to dissect non-canonical CD8 T cells, their restricting molecules, and their ability to protect from diverse viruses. We hope these data will lead to larger projects designed to decipher the mechanisms, perhaps shared with CMV, that lead to these highly potent alternate CD8 T cell responses.