In-vitro inhibition of FIV replication by CHI1019 (Panel A) and L-870,810 (panel B). MBM cells were infected with FIV-Petaluma (FIV-Pet) in the presence of CHI1019 (panel A) or L-870,810 (panel B), and maintained for seven days in the presence of the inhibitors. FIV replication was quantified by measuring p25 core antigen release in cell culture supernatants. Drug efficacy was assessed as percent decrease in p25 concentrations. Data points represent an average from three independent experiments following appropriate transformations to restore linearity. The solid line is the line best fitting the data points; the dashed curves represent the 95% confidence limits. The EC50 values (reported in the main text) were calculated by transposing onto a linear scale the intersection of the regression line (and 95% confidence limits) with the dotted line corresponding to 50% inhibition of viral replication.