Amplification of full-length HIV-2 envelope genes

In contrast to HIV-1, no studies have been published on the genetic and functional analysis of the envelope gene of primary NSI isolates of HIV-2. However several studies on HIV-1 have shown that NSI strains are the most frequently transmitted strains and probably the most important strains in the pathogenesis of HIV infection. Furthermore, it has been shown that the genetic and biological characteristics of primary isolates of HIV-1 differ widely from those of T-cell-line adapted isolates. Two different polymerase chain reaction (PCR) methods, nested-polymerase chain reaction and overlapp-extension amplification, were used to amplify the envelope genes from a primary non-syncytium-inducing HIV-2 isolate, HIV-2ALI, and from the T-cell line adapted syncytium-inducing isolate, HIV-2ROD. These methods could amplify the complete envelope gene from both viruses. Nested-polymerase chain reaction method was highly sensitive, enabling the amplification of one proviral copy of HIV-2ALI in 10000 peripheral blood mononuclear cells. The use of the methods described herein may help to expand our knowledge on the genetic diversity of HIV-2 as well as on the structure and function of the envelope glycoproteins of primary HIV-2 isolates.