Figure 7.
Inhibitory effect of TSP1 on HIV-1 infectivity. HIV-1 isolate IIIB was preincubated in the absence of TSP1, or with various concentrations of purified TSP1 for 1 h at 37°C. Preincubated virus–TSP1 mixtures were added to target cells either directly (−), or first passed through 0.2 μm filters (+). PMA-activated primary PBMC, SK23 (T cell line) or U937 (promonocytic line) were inoculated with the mois indicated. After an additional 1 h at 37°C, infected cells were washed, cultured for 7 d, and HIV-1 p24 antigen was measured by ELISA. Inhibition is expressed for a single data set as percentage of maximum p24 detected in the absence of TSP1.