EPS8 facilitates uncoating of influenza A virus

Gloria P. Larson; Vy Tran; Shuiqìng Yú; Yíngyún Caì; Christina A. Higgins; Danielle M. Smith; Steven F. Baker; Sheli R. Radoshitzky; Jens H. Kuhn; Andrew Mehle

Viral replication and gene expression were assayed in the EPS8-edited cells. Both EPS8.1 and EPS8.2 cell lines had defects in multicycle replication and viral gene expression assays. Viral titers were reduced by about 10-fold in both EPS8-edited lines compared to parental cells ( Figure 2C ). Viral gene expression was reduced 4-5 fold in A549 cells with edited EPS8 relative to wild type cells ( Figure 2D ). The decrease in viral gene expression was more pronounced in EPS8.2, the cell line with the lower level of EPS8 expressed. Stable complementation with EPS8 rescued viral gene expression in both edited lines ( Figure 2D ), suggesting the defects in gene expression were specifically due to decreases in EPS8 levels. To obtain a true knockout phenotype, EPS8 was edited in 293 cells (Supplemental Figure 3 ). EPS8 knockout 293 cells (EPS8.D1) exhibited a significant decrease in viral gene expression, which was restored by transient complementation ( Figure 2E ). EPS8 editing or knockout thus decreases viral gene expression in two different cell lines.