Characterizing HIV-1 Envs associated with potent bnAbs agains QNEs

该项目的目的是识别和表征来自CAPRISA 002队列的HIV感染者，其具有靶向HIV包膜上的第四中和表位（QNE）的广泛中和抗体。到目前为止，我们已经确定了2个这样的人从28到目前为止研究（莫里斯博士）。其中之一，CAP 256开发了针对QNE的有效抗体，其中包括V1 V2区域（摩尔博士）。 有趣的是，该个体被重复感染（威廉姆森博士），将进行病毒进化研究以鉴定第二种感染病毒以及重组毒株，以确定它们在这些抗体产生中的作用。作为该项目的一部分，我们预计将从另外90例将筛选的受试者中确定另外9例具有靶向QNE的中和抗体的受试者。这将通过对大量多亚型假病毒进行中和试验来完成;中和宽度>60%且不具有抗gp 120或抗MPER中和抗体的假病毒将被视为具有抗QNE抗体。将对中和宽度开发期间选定时间点的包膜基因进行测序，并检测功能性假型的中和敏感性，以确定推定位点。我们将进一步利用嵌合和突变病毒来鉴定中和逃逸突变，作为鉴定抗体靶点的一种方式。这些QNE表位的精细映射和结构将与Pinter博士合作完成（项目1）。单克隆抗体将由中和活性归因于James罗宾逊博士（项目4）的单一特异性的个体制备。这些信息将用于设计免疫原，并由Shiu-lok博士在动物模型中进行测试（项目3）。

The aim of this project is to identify and characterize HIV-infected individuals from the CAPRISA 002 cohort with broadly neutralizing antibodies that target quaternary neutralization epitopes (QNE) on the HIV envelope. To date we have identified 2 such individuals from among the 28 so far studied (Dr Morris). One of these, CAP256 developed potent antibodies against QNE that included the V1V2 region (Dr Moore). Interestingly this individual was super-infected (Dr Williamson) and viral evolution studies will be performed to indentify the second infecting virus as well as the recombinant strains to ascertain their role in the development of these antibodies. As part of this project we anticipate identifying another 9 subjects with neutralizing antibodies that target QNE from among the additional 90 that will be screened. This will be done by performing neutralization assays on a large panel of multi-subtype pseudoviruses; those with >60% neutralization breadth and who do not have anti-gp120 or anti-MPER neutralizing antibodies will be considered as having antibodies against QNE. Envelope genes from selected time-points during the development of neutralization breadth will be sequenced and functional pseudotypes tested for neutralization sensitivity to identify putative sites. We will furthermore make use of chimeric and mutant viruses to identify neutralization escape mutations as a way of identifying the antibody targets. The fine mapping and structure of these QNE epitopes will be done in collaboration with Dr Pinter (Project 1). Monoclonal antibodies will be made from those individuals where the neutralizing activity is attributable to a single specificity by Dr James Robinson (Project 4). This information will be used to design immunogens that will be tested in animal models by Dr Shiu-lok (Project 3).