Sequence variation in the env V3-V4 region of human immunodeficiency virus-1 predominant subtype B strains in Hubei Province / 中华传染病杂志

ABSTRACT

Objective To study the sequence variation in the env V3-V4 human immunodeficiency virus (HIV)-1 predominant subtype B strains in Hubei Province and to understand the epidemic characteristics and mutations of HIV-1. Methods Epidemiologic survey was done in the HIV-1 carriers in Hubei area. HIV-1 env V3-V4 regions were amplified by nested-polymerase chain reaction (nPCR). The sequences were determined and then phylogenetic analysis was performed. The difference of gene distance were checked by chi square test and the variation of gene distance were descriptively analyzed. Results Four HIV-1 strains or circulating recombinant forms (CRF) were identified in Hubei Province subtype B', B'/C, CRF01_AE and C were 82.69%, 7.69%, 7.69% and 1.92% ,respectively. B' strains were closely related with B. CN. RL 42 from Yunnan Province and B. CN. 02. 02HN from Province Henan, the gene distances were 7.08 ± 2.19 and 7.88 ± 2.28, respectively. Genetic divergence of env of B' strains showed that subtype B' has existed in Hubei area for about 10 years. Amino acid sequence analysis of section env showed V4 was more variable than C3, V3. The top four peptides of V3 loop were GPGR (46.5%), GPGK (30.2%), GPGQ (13.6%) and GQGR (9.3%). Predictions for the potential use of co-receptors on the basis of the critical amino acids within V3 loop disclosed that 16.28% were CCR5-using (R5/NSI), 13.95% were CXCR4-using (X4/SI) while the co-receptor usage of the vast majority (69.77%) could not be predicted. The analysis of glycosylation sites showed that there were 9 sites in env V3-V4 regions of HIV-1 strains in Hubei area and there were deletions in 8 of them, Conclusions Subtype B' is still the main epidemic subtype in Hubei Province and high homologous to the strains from Yunan and Henan Province.