Proteases of Human rhinovirus: Role in infection

Abstract

Human rhinoviruses (HRV) are the major etiological agents of the common cold and asthma exacerbations, with significant worldwide health and economic impact. Although large-scale population vaccination has proved successful in limiting or even eradicating many viruses, the more than 100 distinct serotypes mean that conventional vaccination is not a feasible strategy to combat HRV. An alternative strategy is to target conserved viral proteins such as the HRV proteases, 2Apro and 3Cpro, the focus of this review. Necessary for host cell shutoff, virus replication, and pathogenesis, 2Apro and 3Cpro are clearly viable drug targets, and indeed, 3Cpro has been successfully targeted for treating the common cold in experimental infection. 2Apro and 3Cpro are crucial for virus replication due to their role in polyprotein processing as well as cleavage of key cellular proteins to inhibit cellular transcription and translation. Intriguingly, the action of the HRV proteases also disrupts nucleocytoplasmic trafficking, contributing to HRV cytopathic effects. Improved understanding of the protease-cell interactions should enable new therapeutic approaches to be identified for drug development.