Innate Effector Function and HIV-1 Control

描述(由申请人提供)：在缺乏抗逆转录病毒治疗(精英控制者)的情况下，发现一小部分艾滋病毒-1感染者表现出自发控制病毒复制(VL&lt；75拷贝核糖核酸/毫升)，这引起了人们对艾滋病毒-1免疫控制机制(S)的浓厚兴趣。最初，针对HIV-1 Gag蛋白的CD8 T细胞反应在Elite控制者中被发现富含，正如先前对长期非进展者所描述的那样。然而，在我们相关的队列中，大约40%的精英控制者缺乏可检测到的HIV-1特异性Gag T细胞反应，这表明替代的免疫控制机制，如先天免疫效应器反应，也可能有助于持续的病毒控制。最近，保护性自然杀伤(NK)受体等位基因(KIR3DL1High和KIR3DS1)及其对应的MHC-I类HLA-Bw4 80I等位基因(尤其是HLA-B*57)的遗传与艾滋病的延迟进展相关。然而，在HIV-1精英控制者中，关于先天免疫隔膜(NK细胞和树突状细胞)的特征还没有报道。在这里，我们建议测量精英控制者和非控制者的NK细胞和树突状细胞(DC)的表型和功能，这是基于我们在表征HIV感染者的天然免疫方面的长期工作，以及我们最近描述的用于测量DC依赖的NK杀伤的自体HIV-1感染的CD4初级T细胞系统。总之，我们将测试中心假设，即增加的先天效应功能(DC辅助支持和NK细胞毒性)是精英控制者中病毒控制的决定因素，这些受试者是KIR3DL1高或KIR3DS1阳性，与其相应的MHC Class I HLA-Bw4 80I配体无关，与他们的HLA-Bw4 80I等位基因HLA-B*57状态无关。我们将通过两个目标来检验这一假设。首先，我们将通过测量浆细胞样树突状细胞、髓系树突状细胞和NK细胞的频率、激活状态、信号转导能力和细胞因子分泌能力来表征NK和DC亚群的分布和激活潜力。其次，我们将通过铬释放和CD107脱颗粒实验来确定NK细胞对自体HIV-1感染的CD4初级T细胞的结构性和HIV诱导的DC依赖的细胞毒功能。这项提案代表了加州大学旧金山分校、宾夕法尼亚大学和维斯塔尔研究所之间的合作。公共卫生相关性：拟议的研究集中在一小部分艾滋病毒感染者的研究上，这些人在缺乏抗逆转录病毒治疗(精英控制者)的情况下表现出自发控制病毒复制(VL&lt；75拷贝核糖核酸/毫升)，这是因为需要确定对艾滋病毒-1的免疫控制机制(S)。我们的研究计划将测试KIR/HLA基因型和自体HIV-1感染目标细胞的NK裂解之间是否存在联系，以确定基因构成是否分离了与精英控制者缺乏疾病进展相关的不同NK反应。完成后，这项提案将提供第一个证据(或缺乏证据)，证明NK细胞对来自Elite控制器的自体感染目标具有抗HIV功能，从而有助于确定先天性免疫反应是否是一种重要的抗病毒机制，然后可以在其他慢性HIV-1感染的患者环境中独立进行。

DESCRIPTION (provided by applicant): The identification of a small subset of HIV-1 infected subjects that exhibit spontaneous control of viral replication (VL<75 copies RNA/mL) in the absence of anti-retroviral therapy (elite controllers) has heightened interest in the mechanism(s) of immune control over HIV-1. Originally, CD8 T cell responses directed against the HIV-1 Gag protein were found to be enriched in Elite controllers, as has been described previously for long-term non-progressors. However, approximately 40% of elite controllers within our associated cohort lack detectible HIV-1 specific Gag T cell responses suggesting that alternative mechanisms of immune control, such as innate immune effector responses, may also contribute to sustained viral control. Recently, inheritance of protective Natural Killer (NK) receptor alleles (KIR3DL1high and KIR3DS1) in conjunction with their corresponding MHC Class I HLA-Bw4 80I alleles (especially HLA-B* 57) have been found to correlate with delayed progression to AIDS. Nevertheless, characterization of the innate immune compartment (NK cells and dendritic cells) has yet to be reported in HIV-1 elite controllers. Here, we propose to measure the phenotype and function of NKs and dendritic cells (DCs) in elite controller and non-controller subjects based on our long standing work in characterizing innate immunity in HIV infected subjects and our recently described autologous HIV-1 infected CD4 primary T cell system for measuring DC-dependent NK lysis. Together, we will test the central hypothesis that increased innate effector function (DC accessory support and NK cytotoxicity) is a determinant of viral control in elite controller subjects that are KIR3DL1high or KIR3DS1 positive in conjunction with their corresponding MHC Class I HLA-Bw4 80I ligands independent of their HLA-Bw4 80I allele HLA-B*57 status. We will test this hypothesis by two aims. First, we will characterize the NK and DC subset distribution and activation potential by measuring the frequency, activation state, signaling potential and cytokine secretion capacity of plasmacytoid DCs, myeloid DCs, and NK cells. Second, we will determine constitutive and HIV-induced DC-dependent cytotoxic function of NK cells against autologous HIV-1 infected CD4 primary T cell via chromium release and CD107 degranulation assays. This proposal represents a collaboration between the University of California-San Francisco, the University of Pennsylvania and the Wistar Institute. PUBLIC HEALTH RELEVANCE: The proposed study focuses on the study of a small subset of HIV-1 infected subjects that exhibit spontaneous control of viral replication (VL<75 copies RNA/mL) in the absence of anti-retroviral therapy (elite controllers) due to the need to identify mechanism(s) of immune control over HIV-1. Our research plan will test the presence of a link between KIR/HLA genotype and NK lysis of autologous HIV-1 infected target cells to determine if genetic make-up segregates differential NK responses associated with a lack of disease progression in elite controllers. Upon completion, this proposal will provide the first evidence (or lack of thereof) for the anti-HIV function of NK cells against autologous infected targets from Elite controllers, and thus will help determine if innate immune responses are a significant anti-viral mechanism that could then be independently pursued in other patient settings of chronic HIV-1 infection.