The development and pre-clinical assessment of novel HCV vaccines to generate T and B cell immunity

项目总结 丙型肝炎病毒(丙型肝炎病毒)感染了7100多万人，并导致肝脏疤痕和癌症。卓有成效的 迫切需要预防感染的疫苗。这应该是一个可以实现的目标，因为25%的人 自发解决(SR)原发感染，产生抗病毒免疫。一种有效的疫苗可能需要 模拟SR相关的免疫反应，包括诱导抗-HCV中和 抗体(NAB)和丙型肝炎病毒特异性T细胞。实现这一点的一种方法是通过使用病毒载体 已经出现的疫苗(黑猩猩腺病毒[乍得]和改良安卡拉牛痘[MVA]) 作为强大的工具来产生对编码的免疫原的免疫反应，包括丙型肝炎病毒。然而， 病毒遗传多样性是开发丙型肝炎病毒疫苗的主要挑战，至少有八种不同的 丙型肝炎病毒感染者之间和体内的基因分型(GT)和多个亚型。最近，一种病毒载体 编码单个GT-1b序列的疫苗未能预防慢性感染，突显了开发的必要性 使用新的丙型肝炎病毒免疫原产生针对多个GTS的NAB和T细胞的新方法。项目5 测试优化的病毒载体丙型肝炎病毒疫苗策略可以产生抗丙型肝炎病毒抗体和 交叉反应的T细胞。为了验证这一假设，我们将追求三个具体目标。AIM 1使用生物信息学 分析并产生以乍得和MVA编码的新型T细胞免疫原，旨在产生广泛的T细胞 评估近交系、外交系和(人类白细胞抗原-2)人源化小鼠对所有丙型肝炎病毒GTS的细胞覆盖率。最有希望的 T细胞免疫原(S)将进展到AIM 2。AIM 2将增加病毒载体疫苗产生的T细胞 使用遗传佐剂(包括II类不变链的变体)的应答并评估替代方案 腺病毒载体，以克服潜在的抗媒介免疫，这可能存在于人类。目标3将 开发新的疫苗策略，既能产生抗丙型肝炎病毒抗体，又能产生T细胞。这将通过以下方式实现 评估：i)病毒载体疫苗中编码的不同B细胞免疫原(在项目2和3中确定)； 二)将有希望的T细胞疫苗候选疫苗与旨在产生包括病毒在内的bNAbs的战略结合起来 呈现项目3中的丙型肝炎病毒包膜(E2)的类似颗粒(VLP)或纳米颗粒 表达E蛋白；以及iii)开发一种编码最佳 B细胞和T细胞免疫原共同作用。重要的是，该项目还将考虑合作伙伴的调查结果 项目应确定与SR相关联的T细胞图谱(项目1)或病毒序列基序(项目4)。 AIMS将共同为开发优化的病毒载体丙型肝炎疫苗战略做出贡献 对恒河猴进行评估，以期在未来进行人类临床试验。

PROJECT SUMMARY Hepatitis C virus (HCV) infects more than 71 million people and causes liver scarring and cancer. An effective vaccine to prevent infection is urgently required. This should be an achievable goal, since 25% of individuals spontaneously resolve (SR) primary infection generating anti-viral immunity. An effective vaccine may need to mimic the immune responses associated with SR including the induction of anti-HCV neutralizing antibodies (NAbs) and HCV-specific T cells. One method to achieve this, is through the use of viral vectored vaccines (both chimpanzee Adenoviral [ChAd] and modified vaccinia Ankara [MVA]), which have emerged as powerful tools to generate immune responses against an encoded immunogen, including HCV. However, viral genetic diversity is a major challenge for the development of HCV vaccines, with at least eight distinct genotypes (gt) and multiple subtypes between and within HCV infected people. Recently, a viral vectored vaccine encoding a single gt-1b sequence failed to prevent chronic infection, highlighting the need to develop new approaches with novel HCV immunogens that generate NAbs and T cells against multiple gts. Project 5 tests the hypothesis that an optimized viral vectored HCV vaccine strategy can generate anti-HCV nAbs and cross-reactive T cells. To test this hypothesis, we will pursue three specific aims. Aim 1 uses bioinformatic analysis and generates novel T cell immunogens encoded in ChAd and MVA, designed to generate broad T cell coverage to all HCV gts assessed in inbred, outbred and (HLA-2) humanised mice. The most promising T cell immunogen(s) will then progress to aim 2. Aim 2 will increase viral vectored vaccine generated T cell responses using genetic adjuvants (including variants of class II invariant chain) and assess alternative adenovirus vectors to overcome potential anti-vector immunity, that may be present in humans. Aim 3 will develop new vaccine strategies to generate both anti-HCV Abs and also T cells. This will be achieved through assessing: i) Different B cell immunogens (identified in project 2 and 3) encoded in viral vectored vaccines; ii) Combining promising T cell vaccine candidates with strategies designed to generate bNAbs including Viral Like Particles (VLP) or nanoparticles that present the HCV envelope (E2) from Project 3 or with a ChAd expressing E proteins; and iii) developing a single ‘bivalent’ viral vectored vaccine that encodes the optimal B cell and T cell immunogens together. Importantly, the project will also take account of findings in partner projects should T cell profiles (project 1) or viral sequence motifs (project 4) linked to SR be identified. Together the aims will contribute to developing an optimized viral vectored HCV vaccine strategy for assessment in Rhesus monkeys with a view to future human clinical trials.