Association of variations of NAb 2F5 and 4E10 epitopes and disease progression in Chinese antiretroviral treatment-naive patients infected with HIV-1 clade B'

Background Studies on human immunodeficiency virus type 1 (HIV-1) vaccines have recently focused on targeting the conserved neutralizing epitopes 2F5 and 4E10, and hence it is important to understand the extent of mutations in these two viral epitopes Here we investigated the amino acid mutations in epitopes of 2F5 (ELDKWA HIV-1 HXB2 env 662-667 aa) and 4E10 (NWFDIT, HIV-1 HXB2 env 671-676 aa) in the membrane proximal-external region of gp41 from clade B' HIV 1-infected individuals living in Henan province, China We also examined the frequency of a mutation and its relation to disease progression Methods A cohort of 54 treatment naive HIV-1-infected individuals was recruited in this study, and 16 individuals were selected for a short-term longitudinal study on sequence evolution The HIV 1 env gp41 gene was amplified cloned, and sequenced, and predicted amino acid sequences were aligned for analysis Results The mutations E662A and K665E on the 2F5 epitope and N671S and T676S on the 4E10 epitope were seen Simultaneous RNA sequencing showed some discrepancies with proviral DNA sequences In our longitudinal study mutation levels of these two neutralizing epitopes were low but diverse and persistent The frequencies of mutations within the 4E10 peptide NWFDIT in slow progressors were noticeably lower than those in AIDS patients (P<0 05) Conclusions Antigenic variation of the neutralizing epitopes 2F5 and 4E10 is limited in subtype B' infection, and that 4E10 peptide mutation is correlated with disease progression Monitoring epitope mutations will offer useful data for development of the candidate 2F5 like and 4E10-like antibodies to prevent and treat AIDS