Viral control mechanisms of HIV-specific T cells in HIV-infected lymph node

 描述(由申请人提供：淋巴组织是最初播种、传播和长期维持艾滋病毒储存库的关键部位。因此，了解控制和消除淋巴组织中的艾滋病毒所需的T细胞特性和机制对艾滋病毒的治愈、根除和疫苗议程至关重要。这一提议背后的核心问题是，淋巴结(LN)中的HIV特异性CD8+和CD4+T细胞是否具有或能够获得控制或消除HIV感染细胞所需的功能。这些研究是基于这样一个概念，即在HIV受试者或那些没有潜在炎症条件的人中，淋巴中通常没有细胞毒性CD8+(和CD4+)T细胞。直观地说，这在生物学上是有道理的：为什么LN需要细胞毒性T细胞？LN中的细胞毒性T细胞(CD8+或CD4+)将在一定程度上消除抗原提呈细胞，从而抑制免疫反应。然而，在HIV感染、HIV疫苗，特别是基于HIV治愈的策略中，LN内的细胞毒性HIV特异性CD8+T细胞将需要控制或消除病毒感染的CD4+T细胞。我们的初步数据显示，慢性感染者的LN中存在异常调节的穿孔素+HIV特异性CD8+T细胞，CXCR5的表达非常低，CXCR5是进入淋巴滤泡所需的标志，而淋巴滤泡是HIV感染的CD4+T细胞集中的地方。出乎意料的是，抗逆转录病毒治疗似乎逆转了这种情况，LN CD8+T细胞上CXCR5的表达增加，但穿孔素水平降低。这与人们想要的艾滋病毒“休克并杀死”治疗策略中的“杀死”部分相反。我们的发现总体上表明，与推动艾滋病毒治疗和疫苗领域的传统智慧相比，LN CD8+T细胞具有根本不同的功能能力。这些考虑表明，如果存在有效的抗HIV细胞溶解T细胞反应，它不会针对大多数HIV感染者中的LN HIV宿主。为了解决这些问题，我们将检查进行性HIV感染、接受ART治疗的HIV感染以及HIV感染的精英控制者中的LN T细胞对HIV的反应。我们的研究将为治疗操作、工程或疫苗介导的策略提供关键信息，这些策略旨在诱导HIV特异性CD8+T细胞能够归巢到LN的适当区域，以消除HIV储存库。在目标1中，我们将确定抗逆转录病毒治疗对LN总细胞和HIV特异性CD8+和CD4+T细胞的影响，并与HIV感染的慢性进展者和精英控制者进行比较。在目标2中，我们将确定接受抗逆转录病毒治疗的HIV感染者的LN和PBMC来源的CD8+和CD4+T细胞是否具有有效的细胞溶解活性。最后，在目标3中，我们将确定ART对LN CD8+和CD4+HIV特异性T细胞转录调节、激活、细胞毒特性以及激活后LN滞留/排出标志物的影响。

 DESCRIPTION (provided by applicant: Lymphoid tissue is the key site for the initial seeding, dissemination, and long-term maintenance of the HIV reservoir. As such, understanding those T cell properties and mechanisms required for control and elimination of HIV directly within lymphoid tissue are of critical importance to the HIV cure, eradication, and vaccine agenda. The central question underlying this proposal is whether HIV-specific CD8+ and CD4+ T cells in the lymph node (LN) have or can acquire the functional capabilities necessary to control or eliminate HIV infected cells. These studies are predicated on the concept that cytotoxic CD8+ (and CD4+) T cells are normally absent from the lymph node in HIV- subjects or those without underlying inflammatory conditions. Intuitively, this makes biological sense: why would cytotoxic T cells be wanted in a LN? Cytotoxic T cells (either CD8+ or CD4+) in the LN would function in part to eliminate antigen presenting cells, thereby dampening immune responses. However, in HIV infection, HIV vaccines, and especially HIV cure-based strategies, cytotoxic HIV- specific CD8+ T cells within the LN would be needed to control or eliminate virally infected CD4+ T cells. Our preliminary data show the presence of dysregulated perforin+ HIV-specific CD8+ T cells in the LN from chronically infected subjects, with very low expression of CXCR5, a marker required for entry into the lymphoid follicle, where HIV-infected CD4+ T cells are concentrated. Unexpectedly, antiretroviral therapy appears to reverse this, with heightened CXCR5 expression on LN CD8+ T cells, but lower levels of perforin. This is opposite of what one would want as the "kill" component of an HIV "shock and kill" cure strategy. Our findings overall indicate that LN CD8+ T cells have fundamentally different functional abilities compared to the conventional wisdom driving the HIV cure and vaccine field. These considerations suggest that were an effective anti-HIV cytolytic T cell response present, it would not target the LN HIV reservoir in the majority of HIV-infected people. To address these issues, we will examine LN T cell responses against HIV in subjects with progressive HIV infection, ART-treated HIV infection, and elite control of HIV infection. Our studies will provide critical information for therapeutic manipulation, engineering, or vaccine-mediated strategies designed to induce HIV-specific CD8+ T cells capable of homing to appropriate regions of the LN in order to eliminate HIV reservoirs. In Aim 1 we will define the effect of antiretroviral therapy on LN total and HIV-specifc CD8+ and CD4+ T cells compared to HIV infected chronic progressors and elite controllers. In Aim 2, we will determine whether LN- and PBMC-derived CD8+ and CD4+ T cells from ART-treated HIV-infected individuals have effective cytolytic activity. Finally, in Aim 3, we will determine the effect of ART on LN CD8+ and CD4+ HIV-specific T cell transcriptional regulation, activation, cytotoxic properties, and LN retention/egress markers after activation.