The molecular virology and reverse genetics of influenza C virus.

Influenza C virus, an enveloped virus containing seven single-stranded RNA segments of negative polarity, belongs to the genus Influenza C Virus of the family Orthomyxoviridae. A number of questions remain to be resolved with regard to the molecular virology and epidemiology of the virus. To address them, we have established a virus-like particle (VLP) generation system and reverse genetics of the virus and succeeded in clarifying the structure-function relationship of the M1 protein of the virus. Although the approach adopted was similar to that for influenza A virus reverse genetics, the number of infectious influenza C viruses generated was much lower than that for influenza A virus. Based on a comparison of the number of influenza C VLPs with that of influenza A VLPs generated using a similar system, we proposed a virion generation mechanism unique to influenza C virus.