Innate Effector Function and HIV-1 Control

描述（由申请人提供）：鉴定出一小部分HIV-1感染受试者在没有抗逆转录病毒治疗（精英控制者）的情况下表现出病毒复制的自发控制（VL<75拷贝RNA/mL），这提高了人们对HIV-1免疫控制机制的兴趣。最初，发现针对HIV-1 Gag蛋白的CD8 T细胞反应在Elite控制者中富集，正如之前描述的长期非进展者一样。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，这表明免疫控制的其他机制，如先天免疫效应反应，也可能有助于持续的病毒控制。最近，保护性NK受体等位基因（KIR3DL1high和KIR3DS1）及其相应的MHC I类HLA-Bw4 80I等位基因（尤其是HLA-B* 57）的遗传被发现与艾滋病的延迟进展有关。然而，先天免疫区（NK细胞和树突状细胞）的表征尚未在HIV-1精英控制者中报道。在这里，我们建议在精英控制者和非控制者中测量NKs和树突状细胞（dc）的表型和功能，基于我们长期以来在HIV感染受试者中表征先天免疫的工作，以及我们最近描述的用于测量dc依赖性NK裂解的自体HIV-1感染CD4原代T细胞系统。总之，我们将验证一个中心假设，即在kir3dl1高或KIR3DS1阳性的精英控制者中，先天效应功能（DC辅助支持和NK细胞毒性）的增加是病毒控制的决定因素，这些控制者与其相应的MHC I类HLA-Bw4 80I配体独立于其HLA-Bw4 80I等位基因HLA-B*57状态。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、髓细胞样树突状细胞和NK细胞的频率、激活状态、信号传导电位和细胞因子分泌能力来表征NK和DC亚群分布和激活电位。其次，我们将通过铬释放和CD107脱颗粒测定来确定NK细胞对自体HIV-1感染的CD4原代T细胞的组成型和hiv诱导的dc依赖性细胞毒功能。该提案代表了加州大学旧金山分校、宾夕法尼亚大学和Wistar研究所之间的合作。公共卫生相关性：由于需要确定对HIV-1的免疫控制机制，拟议的研究侧重于研究一小部分HIV-1感染受试者，这些受试者在没有抗逆转录病毒治疗（精英控制者）的情况下表现出自发的病毒复制控制（VL<75拷贝RNA/mL）。我们的研究计划将测试KIR/HLA基因型与自体HIV-1感染靶细胞的NK裂解之间的联系，以确定基因组成是否分离了精英控制者中与缺乏疾病进展相关的差异NK反应。一旦完成，这一建议将为NK细胞对抗来自精英控制者的自体感染靶点的抗hiv功能提供第一个证据（或缺乏证据），从而有助于确定先天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研究。

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.