Defining the biological relevance of HIV specific HLA-E restricted CD8 T cell responses

项目总结 已有报道称，人类白细胞抗原-E限制的CD8 T细胞具有多种病毒和细菌肽的特异性。 表明它们在适应性免疫中的作用。由于它们的多态有限，因此通过人类白细胞抗原- E可被认为对疫苗设计是有利的。在SIV/猕猴研究中，对致病SIV的保护 用重组巨细胞病毒载体免疫的50%恒河猴观察到了攻击。这是前所未有的 保护作用独立于抗体，部分归因于诱导MHC-E限制性CD8T细胞。 尽管在几种病毒感染中发现了有希望的结果，但人类白细胞抗原-E特异性CD8 T细胞在HIV中的作用一直是 严重不足的研究。事实上，到目前为止还没有研究检查人类白细胞抗原-E限制性CD8 T细胞(E-CD8)的作用 在艾滋病毒感染和疫苗接种方面。唯一公布的数据表明存在人类白细胞抗原E限制性艾滋病病毒- 特异性CD8T细胞的实验表明，HIV多肽可以与人类白细胞抗原E结合。由于人类白细胞抗原Ia和E 无处不在的共同表达，我们知识中的一个重大差距在很大程度上是由于生物学上的缺失 用于描述人类白细胞抗原Ia和人类白细胞抗原E等位基因在HIV中的贡献的试剂。我们的团队已经产生了人类白细胞抗原E 填补人类白细胞抗原-E限制性CD8 T细胞相关性信息缺失的特异性试剂 目标是艾滋病病毒。我们的初步数据显示，人类白细胞抗原E限制了CD8 T细胞对2个表位的反应 在慢性HIV感染中可以检测到GAG。在许多情况下，这些反应不仅受到E 等位基因还受经典的人类白细胞抗原Ia等位基因影响。此外，在一小部分艾滋病毒感染者中，我们观察到 在没有任何ART的情况下控制病毒的个人，即控制者安装了HLA-E限制性CD8T细胞 反应是多功能的和更高的幅度。相比之下，ART上的病毒携带者 低水平的HLAE抑制CD8T细胞反应，主要诱导干扰素-γ和CD107的表达。 我们还表明，HIV感染细胞中的Gag表位是由人类白细胞抗原E呈递的。最后，我们的试点数据显示 HIV血清阴性献血者中人类白细胞抗原E限制性CD8 T细胞反应的启动。后者强调了有必要 为了了解这些反应是否由预防性疫苗诱导，如果不是，如何优化这些反应，以及 被用于有效的艾滋病毒疫苗。我们强有力的初步发现是在 目前的拨款。我们的首要目标是解决艾滋病毒是否受到 人类白细胞抗原E限制性CD8T细胞的频率、广度和功能。根据我们的数据，我们假设 双重限制的CD8 T细胞将与更广泛的反应相关，这将对预防有用 疫苗和使艾滋病毒更难逃脱。目的1、确定人类白细胞抗原-E限制性CD8T细胞的相关性 在艾滋病毒感染和疫苗接种方面。我们将使用来自急性/慢性感染的样本和两个先前基于CTL的艾滋病毒 疫苗。AIM 2使用基于单细胞的分析来确定αβTCR谱和基因表达模式 人类白细胞抗原E限制的HIV特异性CD8 T细胞，以及这些分子特征与病毒控制的关系。

PROJECT SUMMARY HLA-E restricted CD8 T cells specific to a diverse repertoire of viral and bacterial peptides have been reported indicating their role in adaptive immunity. Due to their limited polymorphism, peptide presentation through HLA- E can be considered advantageous for vaccine design. In SIV/macaque studies, protection from pathogenic SIV challenge was observed in 50% rhesus macaques vaccinated with an RhCMV based vector. This unprecedented protection was independent of antibodies and attributed in part to an induction of MHC-E restricted CD8 T cells. Despite promising findings from several viral infections, role of HLA-E specific CD8 T cells in HIV has been grossly understudied. In fact, no study to date has examined the role of HLA-E restricted CD8 T cells (E-CD8s) in HIV infection and vaccination. The only published data to suggest the presence of HLA-E restricted HIV- specific CD8 T cells are experiments demonstrating that HIV peptides can bind to HLA-E. Since HLA-Ia and E are ubiquitously co-expressed, a significant gap in our knowledge has largely been due to absence of biological reagents to delineate the contribution of HLA-Ia vs. HLA-E alleles in HIV. Our group has generated HLA-E specific reagents to address the missing gaps in information on the relevance of HLA-E restricted CD8 T cells targeting HIV. Our preliminary data shows that HLA-E restricted CD8 T cell responses specific for 2 epitopes in Gag can be detected in chronic HIV infection. In many cases, these responses were not only restricted by E allele but also by classical HLA-Ia alleles. Furthermore, in small subset of HIV infected individuals, we observed that in individuals who control virus, without any ART i.e. controllers mounted HLA-E restricted CD8 T cell responses that were polyfunctional and higher in magnitude. In comparison, viremic individuals on ART mounted lower magnitude of HLA-E restricted CD8 T cell responses that mainly induced IFN-γ and CD107 expression. We also show that Gag epitopes are presented by HLA-E in an HIV infected cell. Finally, our pilot data shows priming of HLA-E restricted CD8 T cell responses in HIV seronegative donors. The latter underscores the need to see if these responses are induced by preventative vaccines and if not how can these be optimized and harnessed for effective HIV vaccines. Our strong preliminary findings are foundational for the work proposed in the current grant. Our overarching goal is to address the central question of whether HIV is impacted by the frequency, breadth, and functionality of HLA-E restricted CD8 T cells. Based on our data, we hypothesize that dually restricted CD8 T cells will be associated with a broader response which would be useful for a preventative vaccine and make HIV escape more difficult. Aim 1, determines the relevance of HLA-E restricted CD8 T cells in HIV infection and vaccination. We will use samples from acute/chronic infection and 2 prior CTL based HIV vaccines. Aim 2 uses single cell based analyses to determine αβTCR repertoire and gene expression patterns of HIV specific CD8 T cells restricted by HLA-E and how these molecular signatures relate to viral control.