Both influenza hemagglutinin and polymerase acidic genes are important for delayed pandemic 2009 H1N1 virus clearance in the ferret model.
We previously showed that a pandemic virus, A/Tennessee/560/09(H1N1), had the potential to adapt to human bronchial epithelial cells by the acquisition of hemagglutinin (HA) K154Q and polymerase acidic (PA) protein L295P mutations that conferred a more virulent phenotype. To better elucidate the role of each mutations, we generated recombinant viruses carrying single mutations or both mutations concurrently. The replication of all mutant viruses was significantly higher than that of the wild-type A/Tennessee/560/09 virus in human cells. The HA K154Q mutation reduced the receptor binding affinity of A/Tennessee/560/09 virus to 6-Su-6'SLN and biantennary 6'SLN receptors. In ferrets, H1N1 virus with HA K154Q and PA L295P mutations exhibited significantly higher titers in the upper respiratory tract compared to all other viruses 6 days post-infection. Our results suggest that both single mutations HA K154Q and PA L295P are necessary for delayed virus clearance of A/Tennessee/560/09(H1N1) influenza virus in a ferret animal model.
Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105-3678, USA.
Mariette F
MF
Ducatez
Natalia A
NA
Ilyushina
Thomas P
TP
Fabrizio
Jerold E
JE
Rehg
Nicolai V
NV
Bovin
Robert G
RG
Webster
Richard J
RJ
Webby
D000818:Animals; D002460:Cell Line; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D004195:Disease Models, Animal; D005289:Ferrets / Q000821:virology*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000472:pathogenicity*; D007251:Influenza, Human / Q000821:virology; D009976:Orthomyxoviridae Infections / Q000821:virology; D058873:Pandemics; D013997:Time Factors; D017201:Virus Shedding
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D012321:DNA-Directed RNA Polymerases