Characterizing HIV-1 Envs associated with potent bnAbs agains QNEs

该项目的目的是从CAPRISA 002队列中识别和表征具有针对艾滋病毒包膜上的四元中和表位(QNE)的广谱中和抗体的艾滋病毒感染者。到目前为止，我们已经从28名研究对象中确定了2名这样的人(莫里斯博士)。其中，CAP256开发出了针对QNE的有效抗体，其中包括V1V2区(摩尔博士)。 有趣的是，这个人是超级感染的(威廉姆森博士)，将进行病毒进化研究，以确定第二个感染病毒以及重组株，以确定它们在这些抗体的发展中所起的作用。作为该项目的一部分，我们预计将从将进行筛查的另外90名受试者中识别另外9名具有针对QNE的中和抗体的受试者。这将通过对一大批多亚型伪病毒进行中和试验来完成；那些中和广度为60%且没有抗gp120或抗MPER中和抗体的人将被视为具有针对QNE的抗体。将对中和广度发展过程中选定时间点的包膜基因进行测序，并对功能假型进行中和敏感性测试，以确定可能的位置。我们还将利用嵌合和突变病毒来识别中和逃逸突变，以此作为识别抗体靶标的一种方式。这些QNE表位的精细映射和结构将与品特博士合作完成(项目1)。将从那些中和活性归因于詹姆斯·罗宾逊博士(项目4)的单一特异性的个体中制备出单抗。这些信息将被用于设计免疫原，并将由绍乐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).