A single amino acid substitution in the hemagglutinin of H3N2 subtype influenza a viruses is associated with resistance to the long pentraxin PTX3 and enhanced virulence in mice

Abstract

The long pentraxin, pentraxin 3 (PTX3), can play beneficial or detrimental roles during infection and disease by modulating various aspects of the immune system. There is growing evidence to suggest that PTX3 can mediate antiviral activity in vitro and in vivo. Previous studies demonstrated that PTX3 and the short pentraxin serum amyloid P express sialic acids that are recognized by the hemagglutinin (HA) glycoprotein of certain influenza Aviruses (IAV), resulting in virus neutralization and anti-IAVactivity. In this study, we demonstrate that specificity of both HA and the viral neuraminidase for particular sialic acid linkages determines the susceptibility of H1N1, H3N2, and H7N9 strains t..