Effect of Activation and Inhibition of Cellular PKR on Coxsackievirus B3 Replication

The ds-RNA activated protein kinase (PKR) is a serine-threonine kinase with MW of 68 KDa. It belongs to a family of kinases that control one of the translational initiation factors, eIF2. PKR is produced at high level in response to viral infection. This protein by phosphorylating eIF2 inhibits cellular protein synthesis. In this study, the effect of gamma interferon (IFN-γ), an activator, and 2-aminopurine (2AP), an inhibitor of PKR production on coxsackievirus B3 (CVB3) replication were studied. After addition of IFN-γ and 2AP to Vero and HeLa cultures, cells were infected with CVB3. After 48 h and appearance of cytopathic effect (CPE), cells were collected and viral replication was assessed by standard method. For molecular detection of PKR, RT-PCR technique was used. The data show that interferon inhibited (or lowered) and 2AP promoted viral replication, though in all samples presence of PKR-mRNA could be detected. It seems that PKR plays a key role in CVB3 replication. Therefore, PKR can be considered as a promising and considerable target for designing small molecules and drugs against CVB3.