Role of Viral Reservoirs in the Pathogenesis of HIV Disease

病毒库在 HIV 疾病发病机制中的作用

• 批准号: 8745373
• 负责人: Anthony S. Fauci
• 金额: $ 99.79万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8745373
• 关键词: Antigen Receptors; Autologous; Back; CD19 Antigens; CD28 gene; CD3 Antigens; CD4 Positive T Lymphocytes; CD8B1 gene; Cancer Patient; Cell Count; Cell Line; Cells; Chronic Lymphocytic Leukemia; Coculture Techniques; Coupled; Cytotoxic T-Lymphocytes; Data; Detection; Disease; Disease Progression; Disease remission; Effector Cell; Enzyme-Linked Immunosorbent Assay; Escape Mutant; Frequencies; Goals; HIV; HIV Infections; Immune; Immunity; Immunologics; Individual; Infusion procedures; Interferon Type II; Longevity; Lymphoid Tissue; Macrophage Inflammatory Protein-1; Monitor; Pathogenesis; Patients; Plasma; Research; Residual state; Rest; Role; Site; Specificity; T-Lymphocyte; TNF gene; Therapeutic; Time; Viral; Viral Antigens; Viremia; Virus; antiretroviral therapy; base; chemokine; cytokine; cytotoxic; in vivo; interest; killings; patient population; peripheral blood; receptor; therapeutic development

Over a decade ago, we demonstrated that the latent viral reservoir in the resting CD4+ T cell compartment persists in virtually all HIV-infected individuals receiving clinically effective ART. In addition, we demonstrated that HIV continually replicates at low levels in chronically infected individuals who are consistently aviremic during prolonged periods of receiving ART. Consequently, the persistent viral reservoir has become a major impediment to the eradication of HIV in infected individuals receiving ART. In recent years, major research efforts have been dedicated to a better understanding of the pathogenesis of persistent HIV infection and to the development of therapeutic strategies aimed at eradicating virus in infected individuals receiving ART. During the past year, we have focused our research on: 1) examining the effect of ART on HIV reservoirs in elite controllers and 2) developing immune-based therapeutic strategies that target persistently infected CD4+ T cells. First, we investigated the effect of ART on the persistent HIV reservoirs in elite controllers. Although ART suppresses plasma viremia to below the limit of detection in the vast majority of HIV-infected individuals, the virus cannot be eradicated by therapy alone due in part to the persistence of viral reservoirs in the peripheral blood, lymphoid tissues, and other sequestered sites. Consequently, there is a growing interest in developing therapeutic strategies to eliminate persistent HIV reservoirs and/or to enhance host immunity against the virus in order to control viral replication in the absence of ART. In this regard, it has been shown that a small proportion of HIV-infected individuals spontaneously control plasma viremia in the absence of ART (controllers). Moreover, a subset of such individuals (elite controllers) are capable of maintaining relatively normal CD4+ T cell counts and undetectable levels of plasma viremia for years to decades without the need for ART. Although previous studies have suggested that ongoing viral replication may occur in elite controllers, precise frequencies of infected CD4+ T cells carrying replication-competent virus and/or the impact of ART on immunologic and virologic parameters have not been fully delineated in this patient population. Therefore, we conducted a study in order to determine the effect of ART on the dynamics of persistent HIV reservoirs and various immunologic parameters in elite controllers. We demonstrated that a short course (9 months) of ART dramatically decreased the infectious HIV burden in elite controllers, providing compelling evidence that onging/residual viral replication occurs in such aviremic individuals. The infectious HIV burden in the CD4+ T cell compartment of the elite controllers rebounded back to their original baseline levels upon cessation of ART, an indication that a virologic set-point exists even at this very low level of viral replication, and that host immunity can efficiently control plasma viremia without completely eliminating the infected CD4+ T cells. We also demonstrated that the level of HIV-specific CD8+ T cells in elite controllers gradually declined upon initiation of ART, further supporting the concept that low levels of viral replication occur in these infected individuals. Our data provide compelling evidence that ongoing HIV replication occurs in elite controllers. Given that these individuals effectively control viral replication and lack disease progression in the absence of ART, our study has implications for the feasibility of attaining sustained virologic remission in non-controllers without complete suppression or elimination of viral replication in the face of discontinuation of ART. Second, we investigated the feasibility of eliminating HIV-infected CD4+ T cells using autologous CD8+ T cells that express a chimeric antigen receptor (CAR). Recent studies have demonstrated that complete remission can be achieved in patients with chronic lymphoid leukemia upon infusion of autologous CD8+ T cells expressing CAR with specificity for the B cell antigen CD19 coupled with CD3-zeta, and costimulatory molecules. Inspired by these studies, we investigated whether autologous CD8+ T cells expressing CAR specific for HIV Env could eliminate persistently infected CD4+ T cells from HIV-infected individuals receiving ART. Three CAR constructs were evaluated. All constructs included CD4 for recognition of HIV Env on infected targets, CD3-zeta for cytotoxic activity, and one of the following constimulatory molecules: mock, 4-1BB, or CD28. Autologous CD8+ T cells expressing the above CAR proteins were cocultured with pre-stimulated CD4+ T cells from HIV-infected individuals receiving ART and the level of viral replication was monitored by p24 ELISA over time. Our preliminary data suggest that the highest level of HIV suppression can be achieved when CD8+ T cells expressing the CAR that contains CD28 are cocultured with infected target cells. Our data also show that CD8+ T cells expressing the above CAR construct produce higher levels of intracellular cytokines and chemokines (such as IFN-g, TNF-a, MIP-1) compared to those expressing CAR with mock or 4-1BB upon incubation with a cell line expressing HIV Env. Taken together, our preliminary data suggest that the elimination of persistently infected CD4+ T cells from HIV-infected individuals ex vivo can be achieved with autologous CD8+ T cells that express a CAR that recognizes HIV Env. Because CD8+ cytotoxic T cells do not require viral antigen specificity (besides recognition of HIV Env) for killing, such effector cells could potentially eliminate infected target cells without inducing viral escape mutants. In addition, considering the longevity of CAR-transduced CD8+ T cells observed in cancer patients (years to decades), these cells could restrict viral replication in vivo for extended periods of time.

十年前，我们证明了静止的CD4+ T细胞室中的潜在病毒储层在几乎所有接受临床有效ART的HIV感染者中持续存在。此外，我们证明了艾滋病毒在长期接受ART期间始终处于持续的恶毒性中的慢性感染者中不断复制。因此，持续的病毒储层已成为对受感染的接受艺术的感染者消除艾滋病毒的主要障碍。近年来，主要的研究工作一直致力于更好地了解持续性HIV感染的发病机理以及旨在消除受感染者接受艺术的病毒的治疗策略的发展。在过去的一年中，我们将研究重点放在：1）研究ART对精英控制器中HIV储层的影响，以及2）制定基于免疫的治疗策略，这些策略靶向持续感染的CD4+ T细胞。 首先，我们研究了艺术对精英控制器中持续的艾滋病毒水库的影响。尽管ART抑制了绝大多数HIV感染者的血浆病毒血症至低于检测的极限，但是仅通过治疗就可以通过治疗来消除该病毒，部分原因是由于外周血，淋巴样组织和其他隔离部位在外周血，淋巴组织中的持续存在。因此，人们对制定治疗策略的兴趣越来越大，以消除持续的HIV水库和/或增强对病毒的宿主免疫，以控制在没有艺术的情况下控制病毒复制。在这方面，已经表明，在没有ART（控制器）的情况下，一小部分HIV感染的个体自发控制血浆病毒血症。此外，此类个体（精英控制器）的子集能够维持相对正常的CD4+ T细胞计数和几十年来不需要艺术的血浆病毒血症的水平和无法检测到的水平。尽管先前的研究表明，精英控制器可能会发生持续的病毒复制，但是在该患者人群中，携带复制能力病毒和/或ART对免疫学和病毒参数的影响的精确频率和/或ART对免疫学和病毒参数的影响尚未完全描述。因此，我们进行了一项研究，以确定ART对精英控制器中持续的HIV储量动力学和各种免疫学参数的影响。我们证明，短期（9个月）的艺术急剧减轻了精英控制器中的感染性艾滋病毒负担，提供了令人信服的证据，表明这种恶毒的个体发生了出现/残留的病毒复制。精英控制器的CD4+ T细胞室中的感染性HIV负担在停止艺术后反弹回了原始的基线水平，这表明即使在这种非常低的病毒复制水平下，病毒学设定点也存在，并且宿主免疫可以有效地控制血浆病毒血症，而无需完全消除受感染的CD4+ T细胞。我们还证明了精英控制器中的HIV特异性CD8+ T细胞水平在开始艺术时逐渐下降，进一步支持了这些受感染个体中病毒复制水平较低的概念。我们的数据提供了令人信服的证据，表明正在进行的HIV复制发生在精英控制器中。鉴于这些人在缺乏艺术的情况下有效地控制了病毒复制并缺乏疾病的进展，因此我们的研究对在不完全抑制或消除艺术的情况下，在不完全抑制或消除病毒复制的情况下实现了持续的病毒性缓解的可行性。 其次，我们研究了使用表达嵌合抗原受体（CAR）的自体CD8+ T细胞消除HIV感染的CD4+ T细胞的可行性。最近的研究表明，在输注具有特异性的自体CD8+ T细胞后，对B细胞抗原CD19与CD3-ZETA和costimulation Moleces输注自体CD8+ T细胞后，可以完全缓解慢性淋巴性白血病患者。受这些研究的启发，我们调查了表达针对HIV Env的CAR的自体CD8+ T细胞是否可以消除接受ART的HIV感染者的持续感染CD4+ T细胞。评估了三个汽车构造。所有构建体均包括用于识别感染靶标HIV ENV的CD4，用于细胞毒性活性的CD3-ZETA以及以下残留分子之一：模拟，4-1BB或CD28。将表达上述CAR蛋白的自体CD8+ T细胞与受HIV感染的个体的预刺激的CD4+ T细胞共培养，并随着时间的推移通过P24 ELISA监测病毒复制水平。我们的初步数据表明，当表达包含CD28的汽车的CD8+ T细胞与感染的靶细胞共培养时，可以实现最高水平的HIV抑制。我们的数据还表明，与表达模拟的汽车或与表达HIV Env的细胞系一起孵育后，表达上述汽车结构的CD8+ T细胞会产生更高水平的细胞内细胞因子和趋化因子和趋化因子（例如IFN-G，TNF-A，MIP-1）。综上所述，我们的初步数据表明，可以用自体CD8+ T细胞来实现从HIV感染的个体中消除持续感染的CD4+ T细胞，该CD8+ T细胞表达识别HIV Env的汽车。由于CD8+细胞毒性T细胞不需要病毒抗原特异性（除了识别HIV ENV）来杀死，因此这种效应细胞可能会潜在地消除受感染的靶细胞而不会诱导病毒逃逸突变体。此外，考虑到在癌症患者中观察到的CAR诱导的CD8+ T细胞的寿命（数十年），这些细胞可能会在长时间内限制体内病毒复制。