J Gen Virol. 2010 Sep; 91(Pt 9):2374-80.

PubMed ID: 20484560

Novel subtype C human immunodeficiency virus type 1 envelopes cloned directly from plasma: Coreceptor usage and neutralization phenotypes

Koh WW, Forsman A, Hue S, van der Velden GJ, Yirrell DL, McKnight A, Weiss RA, Aasa-Chapman MM

Human immunodeficiency virus type 1 (HIV-1) is classified into different phylogenetic subtypes, with subtype C representing more than half of the novel infections globally. However, there are relatively few subtype C envelopes available for study. We amplified 18 unique env genes from 13 patients who were infected with subtype C HIV-1 in six African countries and in Scotland to create replication-competent viruses. These envelopes are phylogenetically diverse across the subtype C spectrum, and have on average more N-linked glycosylation sites and slightly longer variable loops than previously described C envelopes. We found that CCR3 coreceptor usage is less prevalent in subtype C than in subtype B viruses, and these envelopes have varied sensitivity to neutralization. The subtype C chimeric viruses generated in this study will be useful for evaluating the breadth of neutralizing antibodies and other entry inhibitors.