Neuraminidase stalk length and additional glycosylation of the hemagglutinin influence the virulence of influenza H5N1 viruses for mice.
Following circulation of avian influenza H5 and H7 viruses in poultry, the hemagglutinin (HA) can acquire additional glycosylation sites, and the neuraminidase (NA) stalk becomes shorter. We investigated whether these features play a role in the pathogenesis of infection in mammalian hosts. From 1996 to 2007, H5N1 viruses with a short NA stalk have become widespread in several avian species. Compared to viruses with a long-stalk NA, viruses with a short-stalk NA showed a decreased capacity to elute from red blood cells and an increased virulence in mice, but not in chickens. The presence of additional HA glycosylation sites had less of an effect on virulence than did NA stalk length. The short-stalk NA of H5N1 viruses circulating in Asia may contribute to virulence in humans.
Matsuoka
Yumiko
Y
Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Swayne
David E
DE
Thomas
Colleen
C
Rameix-Welti
Marie-Anne
MA
Naffakh
Nadia
N
Warnes
Christine
C
Altholtz
Melanie
M
Donis
Ruben
R
Subbarao
Kanta
K
D000818:Animals; D002645:Chickens; D004912:Erythrocytes / Q000378:metabolism; D006031:Glycosylation; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry* / Q000378:metabolism*; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D051379:Mice / Q000821:virology*; D009154:Mutation / Q000235:genetics; D009439:Neuraminidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009976:Orthomyxoviridae Infections; D013997:Time Factors; D014774:Virulence
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D009439:Neuraminidase