H7N9 Influenza Virus Containing a Polybasic HA Cleavage Site Requires Minimal Host Adaptation to Obtain a Highly Pathogenic Disease Phenotype in Mice.

ABSTRACT: Low pathogenic avian influenza (LPAI) H7N9 viruses have recently evolved to gain a polybasic cleavage site in the hemagglutinin (HA) protein, resulting in variants with increased lethality in poultry that meet the criteria for highly pathogenic avian influenza (HPAI) viruses. Both LPAI and HPAI variants can cause severe disease in humans (case fatality rate of ~40%). Here, we investigated the virulence of HPAI H7N9 viruses containing a polybasic HA cleavage site (H7N9-PBC) in mice. Inoculation of mice with H7N9-PBC did not result in observable disease; however, mice inoculated with a mouse-adapted version of this virus, generated by a single passage in mice, caused uniformly lethal disease. In addition to the PBC site, we identified three other mutations that are important for host-adaptat

SUBMITTER: Chan M 

PROVIDER: S-EPMC7020020 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature