NITRIC-OXIDE INHIBITION OF COXSACKIEVIRUS REPLICATION IN-VITRO

Nitric oxide is a radical molecule with antibacterial, -parasitic, and -viral properties. We investigated the mechanism of NO inhibition of Coxsackievirus B3 (CVB3) replication in vitro by determining the effec t of NO upon a single replicative cycle of CVB3 grown in HeLa cells. T ransfection of inducible NO synthase cDNA into HeLa cells reduces the number of viral particles produced during a single cycle of growth. Si milarly, a noncytotoxic concentration of the NO donor S-nitroso-amino- penicillamine reduces the number of viral particles in a dose-dependen t manner, To explore the mechanisms by which NO exerts its antiviral e ffect, we assayed the attachment, replication, and translation steps o f the CVB3 life cycle, NO does not affect the attachment of CVB3 to He La cells. However, NO inhibits CVB3 RNA synthesis, as shown by a [H-3] uridine incorporation assay, reverse transcription-PCR, and Northern a nalysis, In addition, NO inhibits CVB3 protein synthesis, as shown by [S-35]methionine protein labeling and Western blot analysis of infecte d cells, Thus, NO inhibits CVB3 replication in part by inhibiting vira l RNA synthesis by an unknown mechanism.