Genetic diversity of primary HIV-1 isolates and their sensitivity to antibody-mediated neutralization

Wide differences exist among primary isolates of HIV-1 in their sensitivity to antibody-mediated neutralization. While it is well documented that even short-term tissue culture amplification of HIV-1 leads to a reduction in t he genetic diversity of the viral quasispecies seen in vivo, viral isolates , while relatively homogeneous, are generally not clonal. We investigated w hether the extent of genetic diversity within primary viral isolates correl ates with their general susceptibility to neutralization. We compared the n umber of V1V2 and V3-V5 envelope variants detectable within 16 primary isol ates selected to represent the extremes of the neutralization sensitive and resistant phenotypes. Using DNA heteroduplex tracking assays to estimate t he extent of genetic diversity in these two regions of the envelope locus, we found that these primary isolates were made up of one to five distinguis hable V1V2 and V3-V5 sequence variants. We found that higher levels of env genetic diversity did not correlate with increased resistance to antibody n eutralization. (C) 2000 Academic Press.