Caspase inhibitors suppressed the apoptosis in P815 cells infected with influenza A virus.

<p>VAD (abbreviation of Z-VAD-fmk, pan-caspase inhibitor), IETD (abbreviation of Z-IETD-fmk, caspase-8 inhibitor), and LEHD (abbreviation of Z-LEHD-fmk, caspase-9 inhibitor) were added before and after infection with influenza A viruses, and P815 cells were harvested 24 h after infection. (A) Apoptosis was quantified using flow cytometric analysis. Asterisks indicate that the inhibitor-incubated groups were statistically significantly different from the DMSO-incubated groups, as indicated by ANOVA. (B) The expression of full-length and cleaved PARP in P815 cells was measured using Western blot analysis. Graphs show results of one representative case (out of three).