Molecular analysis of gp41 sequences of HIV type 1 subtype C from India

Sequence polymorphism in HIV type 1 env gene is quite high, and there are little data available for subtype C env gp41 sequences from India. We have presented a molecular sequence analysis for gp41 region of env gene from HIV type 1 subtype C-infected individuals. The samples were obtained from 3 acute seroconverters and 5 seropositive individuals from India, one of whom was a minor. Heteroduplex mobility analysis using V3V5 and gp41 confirmed subtype C infection in all the study subjects. The sequences were analyzed for heterogeneity, polymorphism, and epitope recognition. The phylogenetic and SimPlot analysis showed the monophyletic lineage of Indian sequences. The phylogenetic tree constructed for the 286- to 506-bp region is highly variable and clearly distinguishes the subtype C sequences. The interpatient sequence comparison revealed high genetic diversity ranging from 0.0623 to 2.18 (median, 0.119). This supports the phylogeny where sequences belonging to the 8 study subjects form subclusters within Indian subtype C. A majority of the functional domains of gp41 are well conserved for the seroconverter and seropositive sequences. However, sequence polymorphism is high for the sequences obtained from the minor. The sequences of gp41 would provide valuable information regarding the diversity and its diagnostic implications in HIV/AIDS research.