Inhibition of HIV-1 activity by human crude saliva and purified salivary MUC5B and MUC7 mucins. Crude saliva and purified salivary MUC5B and MUC7 mucins (0.9 mg each) were incubated with subtype D HIV-1 for 60 min and filtered through 0.45 μpore size cellulose acetate filter. As controls HIV-1 treated with media and heat inactivated HIV-1 were used. The filtrates of the mixtures were then incubated with CD4+ CEM SS cells at a concentration of 0.5 × 106cells/ml for 30min, 1h and 3h. After PBS wash cells were cultured and viral replication was measured by a qualitative p24 antigen assay.