Reverse Vaccinology in SHIV Infected Macaques as a Molecular Guide for HIV-1 Vaccine Design

项目总结 合理设计HIV-1疫苗的一个主要障碍是缺乏合适的灵长类模型，在这种模型中 中和抗体(BNAbs)可被普遍诱导，其分子、生物学和免疫学 负责引起这种反应的机制以可重复和迭代的方式进行了研究。最近， 我们证明了由猴-人类免疫缺陷病毒(Shiv)表达的主要hiv-1 env。 在恒河猴(RMS)中，引发的环境抗体协同进化模式与感染 同源病毒株，导致中和广度。这些在环境抗体共同进化中的相似性 人类和恒河猴包括保守的免疫遗传、结构和化学解决方案来识别表位 以及精确的Env氨基酸替换、插入和删除导致病毒持久性。的结构 一种恒河猴bNAb，能够中和208个菌株的49%，揭示了V2-顶峰识别模式 与人bNAbs PGT145和PCT64-35m的同源性较高。另一种恒河猴抗体结合了 HIV-1包膜蛋白与人bNAbs 8ANC131、CH235和VRC01的CD4模拟。基于这些观察 支持恒河猴模型与人类bNAb诱导的相关性，我们在这里提出了一个新的“反向” SIV感染RMS的“疫苗学”策略作为告知和加速HIV-1疫苗设计的“分子指南” 在人类身上。具体目的是：(1)分离针对CD4bs、融合肽、V3糖链和V2顶端的bNAb单抗 来自150个受SHV感染的RMS的子集的表位并表征它们的广度、效力、免疫遗传学、 表位识别的目标表位和结构解决方案。(Ii)鉴定Env-Ab的分子模式 恒河猴种系B细胞未突变共同祖先(UCAS)向成熟bNAbs的共同进化及鉴定 负责推动bNAb谱系亲和力成熟的关键Env中间体，或“免疫类型” 广度。(Iii)设计、构建和鉴定模拟关键环境“免疫类型”的新型SOSIP环境三聚体 并证明它们优先结合bNAb、UcA和中间阶段的Abs。(Iv)进行以下证明- 在24个RMS中进行的Of-Concept临床前疫苗试验，以验证反向工程、B系设计的假设 SOSIP环境三聚体可以在RMS中启动、增强和亲和成熟的bNAb反应，其程度优于 传统的SOSIP环境免疫原，与SOSIP-SIV或仅SIV-SIV免疫相当。

PROJECT SUMMARY A major roadblock to rational HIV-1 vaccine design is the lack of a suitable primate model in which broadly neutralizing antibodies (bNAbs) can be commonly induced and the molecular, biological and immunological mechanisms responsible for eliciting such responses studied in a reproducible and iterative fashion. Recently, we demonstrated that primary HIV-1 Envs, when expressed by simian-human immunodeficiency viruses (SHIVs) in rhesus macaques (RMs), elicited patterns of Env-antibody coevolution strikingly similar to humans infected by homologous virus strains, leading to neutralization breadth. These similarities in Env-antibody coevolution in humans and rhesus included conserved immunogenetic, structural and chemical solutions to epitope recognition and precise Env amino acid substitutions, insertions and deletions leading to virus persistence. The structure of one rhesus bNAb, capable of neutralizing 49% of a 208-strain panel, revealed a V2-apex mode of recognition like that of human bNAbs PGT145 and PCT64-35M. Another rhesus antibody bound the CD4-binding site of HIV-1 Env by CD4 mimicry mirroring human bNAbs 8ANC131, CH235 and VRC01. Based on these observations supporting the relevance of the rhesus model to bNAb induction in humans, we propose here a novel “reverse vaccinology” strategy in SHIV infected RMs as a “molecular guide” to inform and accelerate HIV-1 vaccine design in humans. Specific aims are: (i) To isolate bNAb mAbs targeting CD4bs, fusion peptide, V3 glycan and V2 apex epitopes from a subset of 150 SHIV infected RMs and to characterize their breadth, potency, immunogenetics, target epitopes and structural solutions to epitope recognition. (ii) To characterize molecular patterns of Env-Ab coevolution from rhesus germline B cell unmutated common ancestors (UCAs) to mature bNAbs and to identify key Env intermediates, or “immunotypes,” that are responsible for driving bNAb lineage affinity maturation to breadth. (iii) To design, construct and characterize novel SOSIP Env trimers that mimic key Env “immunotypes” and demonstrate that they bind preferentially to bNAb UCAs and intermediate stage Abs. (iv) To conduct a proof- of-concept preclinical vaccine trial in 24 RMs to test the hypothesis that reverse-engineered, B lineage-designed SOSIP Env trimers can prime, boost and affinity mature bNAb responses in RMs to an extent that is superior to conventional SOSIP Env immunogens and comparable to SOSIP-SHIV or SHIV-only immunizations.