TMPRSS2 is essential for pathogenicity of H7N9 and H1N1 influenza A viruses in mice

Influenza viruses cause an acute infection of the respiratory tract that affects millions of people during seasonal outbreaks and occasional pandemics. Furthermore, the recent outbreak of an avian H7N9 influenza virus in China, which caused severe respiratory disease and 43 deaths to date (WHO, July 4, 2013), demonstrated once again that the emergence of a novel influenza virus poses a continuous and unpredictable threat to public health. Influenza virus infection is initiated by the surface glycoprotein hemagglutinin (HA) through binding to cell surface receptors and fusion of the viral envelope with the endoso…