Analysis of env gene diversity in HIV-1 CRF01_AE subtypes circulating in Hanoi, Vietnam

Abstract

Envelope (Env) glycoprotein of HIV-1 is the major target of the humoral immune response against virus. Since Env is the most variable protein of HIV-1, the humoral immune response against Env may vary amongst different HIV-1 subtypes and CRFs. Understanding diversity of env gene is necessary for the development of a vaccine antigen against HIV. This study performed a sequencing-based characterization to analyze env gene of HIV-1 subtype CRF01_AE in firstly diagnosed HIV-infected patients in Vietnam. Analysis showed the high rate of bearing polymorphic codons in variable region of gp 120 (97%). The highest rate was observed in the sub-regions V1 (80.7%), V2 (83.9%) and V4 (61.3%) with the highest number of polymorphic codons 43, 38 and 39 respectively. The subregions V1 and V2 have 4 highly polymorphic codons with rate higher than 20%, including 138T, 140T, 141N (V1), và 185D (V2) all within determined epitopes. Additionally, the study found changes in HIV-1 circulating CRFs that while CRF01_AE remained dominant (83.8%), CRF01_BC were present quite frequently (16.2%). In conclusion, this study shown the diversity of env gene within circulating HIV-1 subtype CRF01_AE in Vietnam.