Env evolution in humans and RMs

摘要 排除类人猿，印度恒河猴(RMS)的免疫系统与 就像人类一样。因此，人们普遍认为，rm代表了最接近实际的动物模型 评估对艾滋病毒-1的保护性免疫以及可能引起这种保护的疫苗。用于HIV-1的分析 中和抗体(NAB)，RMS在过去感染了猿人免疫缺陷 携带HIV-1环境病毒的病毒(SHIV)在细胞培养或动物传代中大量适应，或者它们 用含有从Env多肽或DNA等多种候选疫苗中的任何一种进行免疫 载体从gp120单体到可溶性稳定环境三聚体(SOSIP)。所有这些研究的结果都是为了 日期是一样的：可以产生ABS来中和异源的第一层病毒，在一些 实例自体的第2级病毒，但通常不是构成几乎所有 主要的艾滋病毒-1毒株，并对艾滋病毒-1的临床传播负责。令人惊讶的是，没有直接的 实验证据表明，RMS具有发展异源第二层广泛中和的潜力 抗体(BNAbs)，即使接种了适当的免疫原。因此，艾滋病毒-1的一个主要障碍 疫苗的发展是，没有动物模型系统可以诱导HIV-1的bNAbs 可靠和一致地证明，更不用说以迭代的方式研究合理的疫苗设计了。 项目1试图通过利用Shaw实验室关于以下方面的最新发现来克服这一障碍 新颖的SHIV设计策略。项目1的科学前提是，由于bNAb的大多数例子 激发来自人类感染HIV-1的原始毒株，这是最有可能诱导bNAbs的方法。 在RMS中，是通过感染带有原始HIV-1包膜病毒的天然构象的SHIV。一个关键假说 我们将测试的是，带有初级或传播性/创立者(T/F)环境的SHIV将与恒河猴生殖系接触 和中间祖先B细胞受体(BCR)，它们与同一环境中参与的那些BCR同源 人类感染和病毒-抗体协同进化模式导致中和抗体产生 在这两个物种中，特异性、效力和广度将是相似的。项目1的具体目标是：(I)分析 11个已知与env结合的新SHIV的体内复制动力学和NAB反应 针对V3-葡聚糖超位点(CH848、CH694、CH040)、V1V2超位点的人bNAb谱系BCR (CAP256SU、ZM233、WITO、Q23、T250-4、CH1012)、CD4bs(CH505)或其他(BG505)，并向下选择 两个SHIV分别接种到9个RMS；(Ii)体内复制动力学分析和环境进化 靶向V3-葡聚糖或V1V2胚系和IA BCR的SHIV的途径；以及(Iii)确定动力学， 多克隆NAB反应和MAP表位特异性的效价和广度 指纹图谱、环境表达克隆和定点突变。项目1将与核心B紧密联系 C用于测序和生物信息学，项目2和3用于提供样本和数据解释。

SUMMARY Excluding the great apes, the immune system of Indian rhesus macaques (RMs) most closely approximates that of humans. Thus, it is widely believed that the RM represents the closest practical animal model for evaluating protective immunity to HIV-1 and vaccines that might elicit such protection. For the analysis of HIV-1 neutralizing antibodies (NAbs), RMs have in the past been infected with simian-human immunodeficiency viruses (SHIVs) that bear HIV-1 Envs that were heavily adapted in cell culture or by animal passage, or they were immunized with any of numerous Env containing candidate vaccines ranging from Env peptides or DNA vectors to gp120 monomers to soluble stabilized Env trimers (SOSIPs). The findings from all such studies to date have been the same: Abs can be generated that neutralize heterologous tier 1 viruses, and in some instances autologous tier 2 viruses, but generally not heterologous tier 2 viruses that constitute virtually all primary HIV-1 strains and are responsible for clinical HIV-1 transmission. Surprisingly, there is no direct experimental evidence that RMs have the potential to develop heterologous tier 2 broadly neutralizing antibodies (bNAbs) even if vaccinated with an appropriate immunogen. Thus, a major roadblock to HIV-1 vaccine development is that there is no animal model system where the elicitation of HIV-1 bNAbs can be reliably and consistently demonstrated, let alone be studied in an iterative fashion for rational vaccine design. Project 1 seeks to overcome this roadblock by capitalizing on recent discoveries by the Shaw lab regarding novel SHIV design strategies. The scientific premise of Project 1 is that since most examples of bNAb elicitation come from natural human infection by primary strains of HIV-1, the most likely means to elicit bNAbs in RMs is by infection with SHIVs bearing primary HIV-1 Envs in their native conformations. A key hypothesis that we will test is that SHIVs bearing primary or transmitted/founder (T/F) Envs will engage rhesus germline and intermediate ancestor B cell receptors (BCRs) that are orthologous to those engaged by the same Envs in human infection and that patterns of virus-Ab coevolution leading to the development of neutralizing antibody specificity, potency and breadth will be similar in both species. Specific Aims of Project 1 are to: (i) analyze in 33 RMs the in vivo replication kinetics and NAb responses of 11 novel SHIVs whose Envs are known to bind to human bNAb lineage BCRs targeting the V3-glycan supersite (CH848, CH694, CH040), V1V2 supersite (CAP256SU, ZM233, WITO, Q23, T250-4, CH1012), CD4bs (CH505) or other (BG505), and down-select to two SHIVs for inoculation into 9 RMs each; (ii) analyze in vivo replication kinetics and env evolutionary pathways of SHIVs targeting V3-glycan or V1V2 germline and IA BCRs; and (iii) determine the kinetics, potency and breadth of polyclonal NAb responses and map epitope specificities by a combination of Env fingerprinting, Env-expression cloning, and site-directed mutagenesis. Project 1 will link closely with Cores B and C for sequencing and bioinformatics and Projects 2 and 3 for sample provision and data interpretation.