FIG 7.
Fructose in human seminal plasma reduces HIV-1 inhibition by the lectin GRFT. (A) HIV-1 infection and GRFT inhibition in hSP fractions from different donors. (Bottom) Infection by virus containing the Env of isolate 1053-07 was measured in DMEM, sSP(+Fr) (15 mM), or whole hSP from individual donors and in the small- and large-solute fractions of all samples. (Top) Infection in the same samples was measured in the presence of 60 nM GRFT. Infection in the presence of GRFT is expressed as a percentage of the level of infection in its absence in the same sample. Group I donor samples showed greater effects of the large-solute fraction on GRFT inhibition than group II samples, whereas group II samples showed greater effects of the small-solute fraction than group I samples. (B) Relationship between the fructose concentration in the small-solute fraction of hSP samples and virus infectivity in the same samples in the presence of GRFT. (C) Supplementation of hSP samples with exogenous fructose rescues virus infectivity in the presence of GRFT. Fructose was added to whole SP or to the large-solute fraction from donor 30 to obtain the indicated concentrations of the saccharide. Error bars, SEM. (D, E) Comparison of HIV-1 inhibition by T-20 and GRFT in the small- and large-solute fractions of donor hSPs. Infectivity by virus containing the isolate 1053-07 Env was measured in the presence of T-20 (6 μM) or GRFT (60 nM) in hSP fractions from different donors. The infectivity measured in each donor sample in the presence of the inhibitors is compared. rs, Spearman correlation coefficient. P values were determined by a two-tailed test.