Mechanisms of HBV Functional Cure During Tenofovir-based ART in HIV/HBV Coinfection

项目摘要/摘要 慢性乙肝病毒感染，影响全球2.4亿人，包括5%-20%的艾滋病毒感染者 个人，由于对急性感染的免疫反应不足和共价持续存在 宿主肝细胞中的闭合环状DNA(CccDNA)。在慢性乙肝的核素(T)类似疗法中， “功能治愈”，核心治疗目标由乙肝表面抗原(HBs)的丢失与或 如果没有表面抗体的发展，发生缓慢(~1%/年)。现在有越来越多的小说 正在开发的治疗方法，如果不能实现病毒学治愈(即，消除 CccDNA库)，包括恢复乙肝病毒特异性免疫的试剂。然而，免疫因素对 实现功能性治愈仍然知之甚少，因为乙肝表面抗原丢失通常很少见，而且很少有研究 评估肝内免疫反应。为了指导艾滋病毒和乙肝病毒混合感染的新疗法的使用，一个更好的 需要了解艾滋病毒和乙肝病毒活性抗逆转录病毒疗法(ART)对免疫控制的影响 乙肝病毒。在赞比亚，我们建立了艾滋病毒-乙肝病毒混合感染(n=303)和乙肝病毒的前瞻性队列。 单一感染(n=63)接受替诺福韦(TDF)治疗的成年人。在这个队列中，有很强的地方性 实验室容量和获取肝脏样本的能力，我们记录了惊人的高乙肝表面抗原丢失率(13.1%) 在接受基于TDF的抗逆转录病毒治疗的前两年内，艾滋病毒-乙肝患者。我们现在建议利用这一独特的 研究HIV感染中乙肝病毒功能治疗的科学机会。我们的中心假设--在艺术中-- 治疗艾滋病毒和乙肝病毒混合感染，强劲的免疫重建释放出增强的乙肝病毒功能治愈 回应-将在3个目标中进行测试。在目标1中，使用肝脏细针抽吸，我们将定义免疫 艾滋病毒-乙肝患者在基于TDF的治疗过程中经历HBs Ag丢失/减少的环境。表型 将比较T细胞和其他免疫细胞类型的反应和单细胞RNA测序特征 通过HIV状态和治疗过程中CD4的变化。在目标2中，我们将确定ART诱导的影响 HIV-HBVc DNA外周转录标志物变化对免疫重建的影响 包括定量的HBs Ag和两个新的标志物，即乙肝核心相关抗原和HBVRNA。在AIM 3、我们将确定HIV-HBV混合感染者中乙肝病毒功能治愈的临床预测因素。这 项目，该项目结合了翻译、临床和流行病学方法，并利用现有的NIH- 资助的队列，将导致更好地了解(A)艾滋病毒对乙肝病毒自然病史的影响，(B)如何 (C)新的外周cccDNA标记物是否对HIV-HBV重叠感染有效 可以在这个人群中使用。这项拟议的研究还将推进更广泛的乙肝治疗议程， 包括将免疫调节与有针对性的病毒学干预相结合的战略，以实现乙肝病毒 功能性治愈。

PROJECT SUMMARY/ABSTRACT Chronic hepatitis B virus (HBV) infection, affecting 240 million worldwide including 5-20% of HIV-infected individuals, results from an inadequate immune response to acute infection and persistence of covalently closed circular DNA (cccDNA) in the host hepatocyte. During nucleos(t)ide analog therapy for chronic HBV, `functional cure', the central therapeutic goal defined by loss of hepatitis B surface antigen (HBsAg) with or without surface antibody development, occurs slowly (~1%/year). There are now a growing number of novel therapies in development to increase HBV functional cure if not achieve virological cure (i.e., elimination of the cccDNA reservoir), including agents to restore HBV-specific immunity. Yet, the immune factors critical to achieving functional cure remain poorly understood because HBsAg loss is usually rare and few studies have assessed intrahepatic immune responses. To guide the use of novel therapies in HIV-HBV coinfection, a better understanding is needed of the impact of HIV and HBV-active antiretroviral therapy (ART) on immune control of HBV. In Zambia, we established a prospective cohort of HIV-HBV coinfected (n=303) and HBV monoinfected (n=63) adults taking tenofovir (TDF)-based therapies. Within this cohort, which has strong local laboratory capacity and access to liver sampling, we documented a strikingly high rate (13.1%) of HBsAg loss among HIV-HBV patients during the first 2 years on TDF-based ART. We now propose to exploit this unique scientific opportunity to investigate HBV functional cure in HIV infection. Our central hypothesis – that in ART- treated HIV-HBV coinfection, robust immune reconstitution unleashes an enhanced HBV functional cure response – will be tested in 3 aims. In Aim 1, using liver fine needle aspirations, we will define the immune milieu in which HIV-HBV patients experience HBsAg loss/reduction during TDF-based therapy. Phenotypic responses and single cell RNA-sequencing signatures of T cells and other immune cell types will be compared by HIV status and CD4 changes during therapy. In Aim 2, we will determine the impact of ART-induced immune reconstitution in HIV-HBV coinfection on the change in peripheral markers of cccDNA transcription including quantitative HBsAg and two novel markers, hepatitis B core-related antigens and HBV RNA. In Aim 3, we will define the clinical predictors of HBV functional cure among HIV-HBV coinfected individuals. This project, which combines translational, clinical, and epidemiological approaches, and leverages an existing NIH- funded cohort, will lead to a better understanding of (a) the impact of HIV on HBV natural history, (b) how immunological therapies might work in HIV-HBV coinfection, and (c) whether novel peripheral cccDNA markers can be used in this population. The proposed research will also advance the broader HBV cure agenda, including the strategy to combine immune modulation with targeted virological interventions to achieve HBV functional cure.