Kinase inhibitor roscovitine as a PB2 cap-binding inhibitor against influenza a virus replication

In this study, we examined the impact of roscovitine, a cyclin-dependent kinase inhibitor (CDKI) that has entered phase I and II clinical trials, on influenza A viruses (IAVs) and its antiviral mechanism. The results illustrated that roscovitine inhibited multiple subtypes of influenza strains dose-dependently, including A/WSN/1933(H1N1), A/Aichi/2/68 (H3N2) and A/FM1/47 (H1N1) with IC50 value of 3.35 +/- 0.39, 7.01 +/- 1.84 and 5.99 +/- 1.89 muM, respectively. Moreover, roscovitine suppressed the gene transcription and genome replication steps in the viral life cycle. Further mechanistic studies indicated that roscovitine reduced viral polymerase activity and bound specifically to the viral PB2cap protein by fluorescence polarization assay (FP) and surface plasmon resonance (SPR). Therefore, we believed roscovitine, as a PB2cap inhibitor, was a prospective antiviral agent to be developed as therapeutic treatment against influenza A virus infection.