加强病毒特异性免疫在体内慢性嗜肝病毒合并感染的治疗性

StephenW

Enhancing Virus-Specific Immunity In Vivo by Combining Therapeutic Vaccination and PD-L1 Blockade in Chronic Hepadnaviral Infection

    Jia Liu,

    Ejuan Zhang,

    Zhiyong Ma,

    Weimin Wu,

    Anna Kosinska,

    Xiaoyong Zhang,

    Inga Möller,

    Pia Seiz,

    Dieter Glebe,

    Baoju Wang,

    Dongliang Yang,

    Mengji Lu,

    Michael Roggendorf mail

    Published: January 02, 2014
    DOI: 10.1371/journal.ppat.100385

Abstract

Hepatitis B virus (HBV) persistence is facilitated by exhaustion of CD8 T cells that express the inhibitory receptor programmed cell death-1 (PD-1). Improvement of the HBV-specific T cell function has been obtained in vitro by inhibiting the PD-1/PD-ligand 1 (PD-L1) interaction. In this study, we examined whether in vivo blockade of the PD-1 pathway enhances virus-specific T cell immunity and leads to the resolution of chronic hepadnaviral infection in the woodchuck model. The woodchuck PD-1 was first cloned, characterized, and its expression patterns on T cells from woodchucks with acute or chronic woodchuck hepatitis virus (WHV) infection were investigated. Woodchucks chronically infected with WHV received a combination therapy with nucleoside analogue entecavir (ETV), therapeutic DNA vaccination and woodchuck PD-L1 antibody treatment. The gain of T cell function and the suppression of WHV replication by this therapy were evaluated. We could show that PD-1 expression on CD8 T cells was correlated with WHV viral loads during WHV infection. ETV treatment significantly decreased PD-1 expression on CD8 T cells in chronic carriers. In vivo blockade of PD-1/PD-L1 pathway on CD8 T cells, in combination with ETV treatment and DNA vaccination, potently enhanced the function of virus-specific T cells. Moreover, the combination therapy potently suppressed WHV replication, leading to sustained immunological control of viral infection, anti-WHs antibody development and complete viral clearance in some woodchucks. Our results provide a new approach to improve T cell function in chronic hepatitis B infection, which may be used to design new immunotherapeutic strategies in patients.

Introduction

Hepatitis B virus (HBV) infection evolves into a chronic liver disease and leads to severe sequelae in about 5% of infected adults and in a larger proportion of children. It is estimated that approximately 400 million people are chronically infected with HBV worldwide. There are two types of antiviral therapies currently available for chronic HBV: treatment with pegylated interferon alpha (PEG-IFNα) and nucleot(s)ide analogues, such as entecavir (ETV) and tenofovir. However, treatment with PEG-IFNα leads to a sustained antiviral response in only about 30% patients and is associated with side effects. The introduction of PEG-IFNα in combination with nucleoside analogues did not significantly increase the rate of sustained responders [1], [2]. Although treatment with nucleoside analogues improves the clinical condition of chronic HBV patients, it is hampered by emergence of drug resistance mutations, and rebounding viremia after cessation of antiviral therapy [3], [4]. Therefore, alternative strategies to treat chronic HBV infection are urgently needed.

Persistent HBV infection is associated with functional exhaustion of virus-specific CD8 T cells [5]. This defect in virus-specific T cells is one of the primary reasons for the inability of the host to eliminate the persisting pathogen. Therefore, therapeutic vaccination, which aims to enhance the patient's own antiviral cellular immune response, has been considered as an alternative therapy. However, the efficacy of such strategies in patients has so far been disappointing [6], [7], [8]. Recent work suggests that the high viral load at the time of vaccination might explain the inefficient responses to therapeutic vaccination [9], [10]. Thus, it is important to develop a therapeutic vaccine strategy which could effectively boost endogenous T cell responses to control persistent viral infections.

Recent studies in chronic virus infection models indicate that the interaction between the inhibitory receptor programmed death-1 (PD-1) on lymphocytes and its ligands plays a critical role in T-cell exhaustion [11], [12], [13], [14]. In various human chronic infections, including HBV, high PD-1 levels are expressed by virus-specific T cells, and improvement of the T-cell function has been obtained in vitro by inhibition of the PD-1/PD-ligand 1 (PD-L1) interaction [15], [16], [17], [18], [19], [20], [21]. Moreover, in vivo blockade of PD-1/PD-L1 pathway has successfully been applied in mice persistently infected with lymphocytic choriomeningitis virus (LCMV) to restore the antiviral function of exhausted T cells, and hence improved the effect of the therapeutic vaccination [11], [22].

We have previously demonstrated that therapeutic DNA vaccines in combination with an antiviral nucleoside analogue result in a prolonged suppression of WHV replication in chronically WHV infected woodchucks [23]. Recently, we have also demonstrated that in vitro blockade of the woodchuck PD-1/PD-L pathway could restore the T cell functions in chronic WHV infection [24]. In this study, we examined whether in vivo blockade of the PD-1 pathway in combination with antiviral nucleoside analogue treatment and therapeutic vaccination could enhance CD8 T cell immunity and lead to the resolution of chronic WHV infection in the woodchuck model. Persistently WHV-infected woodchucks were first treated with antiviral drug ETV to decrease the viral replication, and then received therapeutic vaccination and PD-L1 antibody treatment. This combinatorial therapeutic vaccination potently enhanced WHV-specific CD8 T cell responses, resulted in absence of WHV DNA in plasma and seroconversion to anti-WHs in two animals. However, residual WHV replication was still detectable in the liver of some animals.

StephenW

加强病毒特异性免疫在体内慢性嗜肝病毒合并感染的治疗性疫苗和PD -L1阻断

    刘嘉，

    Ejuan张，

    智勇马，

    吴为民，

    安娜Kosinska ，

    小勇张，

    因加默勒，

    皮娅SEIZ ，

    迪特尔旱田，

    宝驹王，

    东梁杨，

    蒙冀鲁，

    迈克尔Roggendorf邮件

    发布时间： 2014年1月2日
    DOI ： 10.1371/journal.ppat.100385

摘要

乙型肝炎病毒（HBV）的持久性是由CD8 + T细胞表达的抑制性受体细胞程序性死亡-1 （PD- 1）的耗竭容易。的HBV特异性T细胞功能的改善已在体外获得通过抑制PD-1/PD-ligand 1 （PD- L1）的相互作用。在这项研究中，我们研究的PD- 1通路的阻断体内是否增强了病毒特异性T细胞免疫，导致慢性嗜肝病毒感染的土拨鼠模型的分辨率。土拨鼠的PD -1被首次克隆，其特征在于，其对从土拨鼠急性或慢性土拨鼠肝炎病毒（ WHV ）感染的T细胞的表达模式进行了调查。慢性感染WHV的旱獭接受联合治疗与核苷类似物恩替卡韦（ ETV ） ，治疗性DNA疫苗和土拨鼠PD-L1的抗体治疗。 T细胞功能的增益和WHV复制此疗法的抑制进行了评价。我们能够显示， CD8 + T细胞的PD- 1的表达WHV感染期间关联与WHV病毒负荷。在慢性携带者ETV治疗显著降低对CD8 + T细胞PD-1的表达。在PD-1/PD-L1通路对CD8 + T细胞，在用ETV治疗和DNA疫苗组合体内封锁，有力地增强的病毒特异性T细胞的功能。此外，该组合疗法有力地抑制了WHV的复制，导致病毒感染，抗WHS抗体的开发和完整的病毒清除在一些土拨鼠的持久免疫控制。我们的结果提供了一种新的方法，以改善T细胞功能在慢性乙型肝炎感染，其可用于设计患者的新的免疫治疗策略。

介绍

乙型肝炎病毒（ HBV）感染演变成慢性肝病，并导致严重的后遗症在约5 ％的受感染的成年人和儿童的比例较大。据估计，约有400万人被全世界慢性HBV感染。有两种类型的抗病毒疗法的当前可用于慢性HBV ：用聚乙二醇化干扰素α （PEG- IFNα ）和nucleot （次）类似物的治疗，如恩替卡韦（ETV）和替诺福韦。然而，用PEG -IFNα治疗导致在仅约30％的患者持续的抗病毒应答，它与副作用相关。 PEG- IFNα的与核苷类似物的组合引入没有显著提高持续应答率[1]， [2]。虽然随着核苷类似物治疗可改善慢性乙肝患者的临床情况，它是由耐药突变的出现阻碍，并停止抗病毒治疗后，病毒血症反弹[3] ， [ 4 ] 。因此，迫切需要替代策略来治疗慢性HBV感染。

HBV持续感染与病毒特异性CD8 T细胞的功能衰竭相关的[5]。在病毒特异性T细胞的这种缺陷的主要原因为宿主不能消除持续病原体之一。因此，治疗性疫苗，其目的是提高患者自身的抗病毒细胞免疫反应，已被认为是一种替代疗法。然而，在病人这样的策略的有效性至今令人失望[6]， [7]， [8]。最近的研究表明，在高病毒载量在接种时可以解释低效反应治疗性疫苗接种[9] ，[10] 。因此，制定一个治疗性疫苗的策略，能有效地促进内源性T细胞反应为控制持久性病毒感染是很重要的。

最近在慢性病毒感染模型的研究表明，抑制性受体之间的相互作用编程中的T细胞耗竭死亡-1 （PD- 1）对淋巴细胞和它的配体中起着关键作用[11] ，[12] ，[13] ， [14]。在各种人类慢性感染，包括乙型肝炎病毒，高PD-1的水平是由病毒特异性T细胞表达和改善T细胞的功能已在体外获得通过抑制PD-1/PD-ligand 1 （PD的-L1）的相互作用[ 15 ]，[16 ]，[17 ]，[18 ]，[19 ]，[20 ] ，[21] 。此外， PD-1/PD-L1途径在体内封锁已经被成功地在持续感染与淋巴细胞性脉络丛脑膜炎病毒（ LCMV）还原耗尽T细胞的抗病毒功能的小鼠应用，因此提高了治疗性疫苗[ 11的效果] ，[22] 。

之前我们已经证实，在与华纳家庭录影复制的慢性WHV感染的土拨鼠一个长期抑制[23]抗病毒核苷类似物结果组合治疗性DNA疫苗。最近，我们还表明，在体外封锁土拨鼠PD-1/PD-L通路可能在慢性WHV感染[ 24 ]恢复T细胞的功能。在这项研究中，我们研究的PD- 1通路结合抗病毒核苷类似物治疗和治疗性疫苗在体内阻断是否能增强CD8 + T细胞免疫功能，导致慢性WHV感染的土拨鼠模型的分辨率。坚持WHV感染的土拨鼠是先用抗病毒药物ETV ，以减少病毒的复制，然后接受治疗性疫苗和PD -L1抗体治疗。此组合治疗性疫苗接种有力地增强WHV特异性CD8 T细胞应答，导致缺乏WHV DNA在血浆和血清转换到反WHS在两种动物。然而，残留的WHV复制仍然可检测到一些动物的肝脏。

StephenW

我觉得这个研究非常有意义 -这是一个真正的联合治疗法:

1. 除去免疫抑制- 使用恩替卡韦降低HBVDNA
2. 恢复T细胞免疫 - 阻断PD-1/PD-L
3. 促进T细胞的生产 - 使用治疗性疫苗

如果我们加:
1. 除去免疫抑制 - 使用REP9AC/ARC520降低血清HBsAg
2. 提高先天性免疫 - 使用干扰素

结果是什么？

tonychant

REP9AC好久没消息了不会是又一乙克吧！

StephenW

回复 tonychant 的帖子

消息是，今年小的临床试验在欧洲.