Human Respiratory Syncytial Virus - Virology

Virology

RSV has 10 genes encoding 11 proteins—there are 2 open reading frames of M2. NS1 and NS2 inhibit type I interferon activity. N encodes nucleocapsid protein that associates with the genomic RNA forming the nucleocapsid. M encodes the Matrix protein required for viral assembly. SH, G and F form the viral coat. The "G" protein is a surface protein that is heavily glycosylated. It functions as the attachment protein. The "F" protein is another important surface protein; F mediates fusion, allowing entry of the virus into the cell cytoplasm and also allowing the formation of syncytia. The "F" protein is homologous in both subtypes of RSV; antibodies directed at the "F" protein are neutralizing. In contrast, the "G" protein differs considerably between the two subtypes. M2 is the second matrix protein also required for transcription, it encodes M2-1 (elongation factor) and M2-2 (transcription regulation), M2 contains CD8 epitopes. L encodes the RNA polymerase. The phosphoprotein P is a cofactor for L. The atomic structure is now available for two of them, N and M. The genome is transcribed sequentially from NS1 to L with reduction in expression levels along its length