Regulation of host cell signaling pathways by respiratory syncytial virus nonstructural protein NS1 and NS2

Human Respiratory Syncytial virus (hRSV) is a leading cause of severe lower respiratory tract diseases in the pediatric population.hRSV frequently causes severe morbidity and mortality in high risk groups including infants with congenital heart disease and the immunosuppressed patients. Although hRSV is recognized as a major public health threat and economic burden worldwide, there is no licensed vaccine and effective therapeutic agent. Viral nonstructural (NS) proteins have been known to play multiple functions for efficient viral replication and pathogenesis. Especially, diverse functions of influenza A virus NS1 have been extensively studies. Recent studies demonstrated that NS1 and NS2 of RSV also exert diverse functions to modulate cellular environment and antiviral immune responses. Since NS proteins of RSV are required for efficient replication and pathogenesis, NS mutant viruses have been tested as live-attenuated vaccines. This review will outline the recent progress in understanding the various functions of RSV NS1 and NS2.