Popis: |
Sulfated glycolipids (SG) and glycosaminoglycans (GAG) present on the surface of colonic, vaginal epithelial, and neuroglial cells bind to HIV gpl20, suggesting that these glycoconjugates may have a role in HIV infection. The major goal of our study was to test the ability of SG and GAG from human milk to inhibit HIV-1 infection in vitro. SG and GAG were purified from pooled human milk and characterized by high pressure liquid chromatography (HPLC) and mass spectrometry. Eight different preparations of SG and one of GAG were tested for inhibition of infection. Two laboratory isolates, HIV-1Ada (macrophage-tropic virus) and HIV-1SF2 (lymphotropic virus), were used for inhibition assays using peripheral blood mononuclear cells (PBMC) and monocyte-derived macrophages (MDM). Inhibition assays were performed by preincubation of serial dilutions of glycoconjugates with each virus before infecting the monolayer of cultured MDM and PBMC. After 4 days, HIV p24 antigen was quantified by enzyme immunoassay (EIA) in culture supernatants. Significant inhibition of viral infectivity was defined as >80% reduction in p24 concentration. GAG showed a low inhibitory effect (8–44%) in HIV-1 infection of PBMC. Table 1 shows the minimal amounts of the most active SG fractions, expressed as volumes of human milk from which they were extracted, that inhibit >80% HIV-1 infection. |