INTRAPATIENT VARIABILITY OF THE HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-2 ENVELOPE V3 LOOP

Studies of HIV-2 infection have shown lower rates of sexual and perina tal transmission and a prolonged incubation period to AIDS as compared to HIV-1, To evaluate the role of genetic variation in HIV pathogenes is, we studied intrapatient variability in the V3 loop of the HIV-2 en velope gene over time in five seropositive individuals. Proviral seque nces derived from uncultured PBMC DNA (n = 102) demonstrated an averag e sequence heterogeneity within a sample of 1.4% (0-4.1%), This was si gnificantly lower than the V3 sequence heterogeneity observed in HIV-1 , which can be as high as 6.1%, In HIV-2-seropositive healthy patients the average intrapatient nucleotide variability rate was 0.6% compare d to 2.0% in patients with clinical AIDS. The lower rate of variabilit y between HIV-2 and HIV-1 is compatible with differences in transmissi on and pathogenesis of these two related viruses.