Abstract
Human saliva appears to contain factors that are inhibitory to HIV-1 infectivity in vitro. We investigated the effect of incubating human whole, parotid, labial minor salivary gland and sublingual/submandibular salivas with recombinant HIV-1 envelope protein (gpl60). Saliva/gpl60 mixtures were run on polyacrylamide gels, transferred to nitrocellulose, and assayed for the presence of gp 160 using monoclonal antibodies or HIV-1-positive sera. Incubation of the gp 160 with whole saliva reduced the intensity of gp 160 bands to 35% of control values. Minor salivary gland saliva reduced the band intensities to 65% of control values, while other saliva types diminished gp160 to 75% of control values. Protease inhibitors had no effect. Components of untreated whole human saliva prevent the detection of the HIV-1 envelope protein gp 160 by antibodies to gp120 and gp41 in immunoblots. The results suggest that complexes between whole saliva factors and certain domains of gp160 block monoclonal antibody binding or are unable to migrate through polyacrylamide gels.