Neutralization Characteristics of HIV-1 CRF01_AE Env Clones From Infections in China

Owing to the increasing prevalence of HIV-1 CRF01_AE, it is necessary to understand the neutralization properties of CRF01_AE and to develop broadly neutralizing monoclonal antibodies (bnmAbs) that can neutralize this virus. The full-length Env gene was cloned from HIV-1 CRF01_AE-infected plasma specimens collected in China and used to establish pseudoviruses. Neutralization phenotypes of the pseudoviruses were characterized with bnmAbs. The neutralizing activities of 11 bnmAbs VRC01, VRC03, IgG1b12 and 3BNC117 (targeting the CD4 binding site); PG9 (targeting the V1V2 region); 2G12 (targeting the high mannose patch), PGT135 and 10-1074 (targeting the V3 glycans); 2F5, 4E10 and 10E8 (targeting the membrane proximal external region), against 36 pseudoviruses were analyzed, demonstrating varying efficacies. In general, VRC01, 10E8 and 3BNC117 showed strong neutralizing activity, neutralizing more than 75% of the pseudoviruses; followed by PG9 and 4E10, showing moderate neutralizing activity with neutralization of 50%–60% of the pseudoviruses; whereas the efficacies of the remaining bnmAbs were poor, neutralizing less than 15% of pseudoviruses tested. Env variants of CRF01_AE from one infection also showed significant differences in resistance to neutralization. These characterized HIV-1 CRF01_AE pseudoviruses could be used for neutralization studies and evaluation of vaccines or anti-HIV-1 products in China.