CsA selectively inhibited the viral proteins levels in both 293T/CypA+ and 293T/CypA− cells.

<p>Both cell lines were infected with influenza A/WSN/33 at MOI 1. After being washed with PBS, the cells were cultured with fresh medium supplemented without or with CsA (5 µg/ml). At 4 h p.i., 6 h p.i. and 8 h p.i., the cell lysates were collected to detect the M1, NP and NS1 proteins. β-actin as an internal control was also detected by Western blot analysis (A). The relative viral protein levels of M1, NP and NS1 in both 293T/CypA+ and 293T/CypA− cells were calculated by quantifying the results shown in panel (A). The viral titers were detected at 8 h p.i. in two cell lines (B). Data are means ± SD of three separate experiments.