Caraphenol A effect on late endosome is dependent on IFITM3 expression. (A) Representative images of WT TZM-bl and IFITM3 KO cells imaged by confocal microscopy, as above. Cells were plated and treated for 4 hours with caraphenol A (30 μM) or DMSO (0.06%) before addition of LV for 30 minutes or 2 hours. Cells were then fixed, permeabilized, and immunostained using α-IFITM2/3, α-LAMP1 antibodies, and Hoechst 33342 nuclei stain. Scale bars are 10 microns. Images were collected and analyzed as previously described, identifying the number and mean intensity of IFITM2/3- (B) and LAMP1-stained (C) vesicles per cell. Data plotted as dot plots comparing WT (closed symbols) to IFITM3 KO (open symbols) treated with caraphenol A (green symbols) or DMSO (blue symbols, mean ± SD). *P < .032, **P < .0021, ***P < .0002, ****P < .0001 by Kruskal-Wallis test with Dunn’s multiple comparison correction.