Defining the mechanisms of HIV resistance to bNAbs in humans

项目总结 联合抗逆转录病毒疗法(ART)彻底改变了HIV-1感染的治疗和预防。 然而，抗逆转录病毒疗法并不能根除既定的感染，全世界的艾滋病毒-1发病率仍然很高， 一直在缓慢下降。因此，寻找新的预防和治疗干预措施仍然是一项艰巨的任务。 优先考虑。近年来，广谱中和抗体(Bnbs)作为一种替代日常免疫的长效抗体出现。 ART和作为实现长期无治疗艾滋病毒-1控制的一种有前途的战略。BNAbs与艺术的区别在于 它们通过其Fc效应域与宿主免疫系统接触，因此有可能 介导对感染细胞的杀伤，并调节或增强艾滋病毒特异性免疫反应。然而，bNAbs 很容易被HIV-1变种逃脱。在HIV-1感染期间，抗体反应与大量 迅速变异的病毒群体，因此对个别抗体具有抵抗力的变种经常 遇到了。与这种高度的多样性相一致的是，几项临床研究表明，bNAb 单一疗法通过快速选择耐bNAb的病毒株，导致病毒血症的一过性下降。相比之下， 针对非重叠环境抗原表位的两种bNAb的组合在参与者中保持了病毒抑制 携带抗体敏感病毒的，已通过抗逆转录病毒疗法实现病毒抑制，并随后收到 在ART中断期间重复剂量的bNAbs。这些早期研究证明了潜在的治疗方法 BNAbs的应用，但也强调了更好地了解导致bNAb的病毒逃逸途径的必要性 抵抗。虽然对某些bNAbs(即抗V3环)的抵抗力是基于Env的已知特征来预测的，但 对于其他bNAbs和bNAbs的组合，抗性的决定因素没有明确的定义。最重要的是 这项提案的目标是了解导致bNAb逃逸的途径的多样性，并利用这一点 指导设计更有效的优化bNAb组合的信息，以防止出现 抗药性变异体。这项建议有四个相互关联的目标，旨在实现这些目标：(1)确定 导致人类对bNAb给药产生病毒抵抗力的序列元件 下一代深度测序方法；(2)系统地定位所有可能的bNAb抗性突变 通过生产和测试完整的文库来识别跨病毒株和亚型的逃逸机制 (3)确定可选择的临床相关的耐bNAb的HIV-1变异体的性质 在有或没有自体血清的情况下进行细胞培养；(4)开发计算模型，以定义 整合AIMS 1-3获得的序列信息研究HIV-1bNAb耐药机制。

PROJECT SUMMARY Combination antiretroviral therapy (ART) revolutionized the treatment and prevention of HIV-1 infection. However, ART does not eradicate established infection and worldwide HIV-1 incidence rates remain high and have been declining slowly. Thus, the search for novel preventive and therapeutic interventions remains a high priority. In recent years, broadly neutralizing antibodies (bNAbs) emerged as a long-acting alternative to daily ART and as a promising strategy to achieve long-term treatment-free HIV-1 control. bNAbs differ from ART in that they engage the host immune system by virtue of their Fc effector domains and therefore have the potential to mediate killing of infected cells and modulate or enhance HIV-specific immune responses. However, bNAbs are vulnerable to escape by HIV-1 variants. During HIV-1 infection, antibody responses co-evolve with a large population of rapidly mutating viruses, such that variants that are resistant to individual antibodies are frequently encountered. Consistent with this high level of diversity, several clinical studies have demonstrated that bNAb monotherapy leads to transient declines in viremia with rapid selection of bNAb-resistant viral strains. In contrast, a combination of two bNAbs targeting non-overlapping Env epitopes maintained viral suppression in participants harboring antibody sensitive viruses who had achieved viral suppression with ART and subsequently received repeated doses of bNAbs during ART interruption. These early studies demonstrate the potential therapeutic application of bNAbs but also highlight the need to better understand viral escape pathways leading to bNAb resistance. Although resistance to some bNAbs (i.e. anti-V3 loop) is predicated on known features of Env, the determinants of resistance are poorly defined for other bNAbs and for combinations of bNAbs. The overarching goals of this proposal are to understand the diversity of pathways leading to bNAb escape and use this information to guide the design of more effective optimized bNAb combinations that prevent emergence of resistant variants. This proposal has four interrelated aims directed at accomplishing these goals: (1) Determine the sequence elements that lead to viral resistance to bNAb administration in humans using newly developed next generation deep sequencing methods; (2) Systematically map all possible viable bNAb resistance mutations to identify mechanisms of escape across viral strains and subtypes by producing and testing complete libraries of Env mutants; (3) Determine the nature of clinically relevant bNAb-resistant HIV-1 variants that can be selected in cell culture in the presence or absence of autologous serum; (4) Develop computational models that define mechanisms of HIV-1 bNAb resistance by integrating the sequence information obtained from Aims 1-3.