FIG 4.

ADAM9 is required for the entry phase of EMCV infection. (A) EMCV or CV-B3 were pretreated with the indicated concentrations of soluble ADAM9 protein or 100 μg/ml soluble FGFR1α/FGFR1β proteins for 1 h at 37°C and used to infect HAP1 cells. Capsid proteins (EMCV) or 3A protein (CV-B3) and nuclei (blue) were stained at 7 h postinfection. (B) HAP1 cells were pretreated with the indicated concentrations of antibody targeting ADAM9 and infected with virus for 7 h, followed by staining as described above for panel A. Representative confocal micrographs are shown in panels A, B, and C. Values (percentages) on the micrographs are mean ± SEM values for 3 or 4 (A) or 4 (B) technical replicates, normalized to the value for mock treatment. (C) WT, ADAM9^KO, or ADAM9^KO HAP1 cells overexpressing mouse ADAM9 mutant E348A (mADAM9) were incubated with EMCV or CV-B3 on ice, followed by qPCR analysis of bound virus. The values are means plus standard deviations (SD) (error bars) for three biological replicates. Experiments were conducted twice with similar results.