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

项目摘要 合理设计HIV-1疫苗的一个主要障碍是缺乏合适的灵长类动物模型， 中和抗体（bNAb）通常可以被诱导，并且其分子、生物学和免疫学性质可以被改变。 以可重复和迭代的方式研究引起这种反应的机制。最近， 我们证明，当由猴-人免疫缺陷病毒（SHIV）表达时， 在恒河猴（RM）中，引发的Env-抗体协同进化模式与感染了Env的人类惊人相似。 同源病毒株，导致中和宽度。Env-抗体协同进化中的这些相似性， 人类和恒河猴包括保守的免疫遗传学，结构和化学解决方案， 以及精确的Env氨基酸取代、插入和缺失导致病毒持续存在。的结构 一种恒河猴bNAb，能够中和208种菌株的49%，显示出V2-apex识别模式 类似于人bNAb PGT 145和PCT 64 - 35 M。另一种恒河猴抗体结合CD 4结合位点， 通过CD 4模拟反映人bNAb 8ANC 131、CH 235和VRC 01的HIV-1 Env。基于这些观察 为了支持恒河猴模型与人类bNAb诱导的相关性，我们在此提出了一种新的“逆转录病毒”。 SHIV感染RM中的“疫苗学”策略作为“分子指南”，为HIV-1疫苗设计提供信息和加速 在人类身上。（i）分离靶向CD 4 bs、融合肽、V3聚糖和V2顶点的bNAb mAb 表位，并表征其宽度，效力，免疫遗传学， 靶向表位和表位识别的结构解决方案。(ii)表征Env-Ab的分子模式 从恒河猴生殖系B细胞未突变的共同祖先（UCA）到成熟bNAb的共进化， 关键Env中间体或“免疫型”，其负责驱动bNAb谱系亲和力成熟， 宽度(iii)设计、构建和表征模拟关键Env“免疫型”的新型SOSIP Env三聚体 并证明它们优先结合bNAb UCA和中间阶段Ab。(iv)去进行一个证明- 在24个RM中进行的概念性临床前疫苗试验，以检验反向工程、B谱系设计 SOSIP Env三聚体可以在RM中引发、加强和亲和力成熟bNAb应答至优于对照的程度。 常规SOSIP Env免疫原，并且与SOSIP-SHIV或仅SHIV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.