A genetic analysis of HIV-1 from Punjab, India reveals the presence of multiple variants.

ABSTRACT

PIP: Health workers collected blood samples from 12 persons infected with HIV living in the Punjab in India to obtain peripheral blood mononuclear cells so researchers could determine the extent of HIV-1 genetic variation. They prepared multiple clones of the C2/V3-V5 regions of HIV-1 gp120 from the lymphocyte DNA of each patient. They used distance, parsimony, and neighbor-joining algorithms to analyze the inter-isolate relationships. They aligned nucleotide sequences of about 650 base pairs for the Indian and other geographically distinct isolates. All but two cases were males. The two females acquired HIV from their husbands. Based on the nucleotide sequence comparisons, there was low interpatient variation. Amino acid comparisons found a high degree of homology between Indian sequences in this study and those studied previously. Most Indian sequences clustered together as subtype C on the distant and parsimony trees. Three patients had significant homologies and phylogenetic clustering outside of subtype C. One patient had env gene homology to subtype B sequences prevalent in Europe and the Americas. The two others had env gene sequences that clustered away from all presently known subtypes of HIV-1. These three cases were the first sequences divergent from subtype C in India. All of these patients and one that clustered marginally with subtype C had possible contacts outside India. Variant subtypes in Indian patients provide clues on the transmission routes of HIV-1 to India. They also underscore the need for researchers to include these sequences as they develop an HIV/AIDS vaccine. Since the leading HIV-1 strain in India conforms to subtype C and there was limited nucleotide sequence variation in most cases, these findings indicate recent spread of HIV-1 in the Punjab.