Extended Data Figure 9. Toremifene and ibuprofen inhibit fusion of Ebola GP pseudovirus particles.

a, CCF2-loaded TZM-bl cells were exposed to EBOV pseudoparticles (EBOVpp) or control particles lacking envelope proteins (NoENV) at 4 °C to synchronise binding and receptor engagement before fusion was initiated by shifting cells to 37 °C in the presence of Toremefine (15 µM and 1.5 µM), Ibuprofen- (150 µM and 15 µM), or just the compounds solvent (5 % DMSO). After 2h incubation, cells were loaded with the CCF2-AM FRET biosensor, fixed and the ratio of blue (440–480 nm, cleaved CCF2-AM) to green (500–540 nm, un-cleaved CCF2-AM) fluorescence measured. Cells are pseudocolored according to this ratio: blue represents no fusion, red represents fusion. Scale bar: 80 µm. b, The percentage of fusogenic cells (red versus blue) was calculated taking the average max value coming from the negative control as a threshold for fusion, data are means ± s.d. (n=10). Analysis used an unpaired t test and compared to the EBOV + DMSO control, where ns (not significant) = P > 0.05, * = P ≤ 0.05and *** = P ≤ 0.001. Error bars represent standard deviations.