NONSENSE MUTATIONS IN THE VPR GENE OF HIV-1 DURING IN-VITRO VIRUS PASSAGE AND IN HIV-1 CARRIER-DERIVED PERIPHERAL-BLOOD MONONUCLEAR-CELLS

Long-term, persistent infection by HIV-1 is a prerequisite for the dev elopment of AIDS. However, little is known of the determinants require d for HIV-1 to cause persistence. We have reported previously that per sistent infection of a T cell line by a cytopathogenic strain of HIV-1 became increasingly likely with in vitro serial passage of the virus. DNA sequencing of the persistent strains revealed a nonsense mutation in the vpr gene in all isolates tested. Here, we report the developme nt and use of a semi-quantitative PCR method to detect the vpr nonsens e mutation within populations of virus. Our results show that vpr muta nts also arise in cells during acute infection and increase progressiv ely with serial passage of the virus. In addition, HIV-1-seropositive individuals were examined and found to carry the same vpr nonsense mut ation at high frequency in virus-infected PBMC. These data are consist ent with a mechanism of HIV-1 persistence in vivo and in vitro in whic h virus cytopathogenic potential is lost by the build up of nonsense m utations in vpr.