title: Contribution of H7 haemagglutinin to amantadine resistance and infectivity of influenza virus.
abstract: In the present study we determined the antiviral effect of amantadine against influenza A/Netherlands/219/03 (H7N7) virus in cell culture and in a mouse model. Amantadine at concentrations <100 muM failed to inhibit virus replication in Madin-Darby canine kidney (MDCK) cells. When orally administered to mice for 5 days, amantadine at 15 mg kg(-1) day(-1) did not protect animals against lethal challenge with H7N7 infection, and virus titres in mouse organs were not reduced. However, sequence analysis of the M2 protein revealed none of the mutations previously described as being associated with amantadine resistance. We used reverse genetics to generate viruses containing the haemagglutinin (HA) or M gene of A/Netherlands/219/03 virus to investigate the role of these genes in amantadine sensitivity. All recombinant viruses carrying the HA segment of A/Netherlands/219/03 (H7N7) virus were amantadine-resistant, regardless of the origin of their other genes. To study the role of fusion activity in the mechanism of drug resistance, we introduced the Gly(23)-->Cys mutation in the H7 fusion peptide. This substitution resulted in a decrease of the pH of fusion and was also associated with reduced virus replication in both MDCK cells and mice, as compared to that of the wild-type virus. We suggest that H7 HA protein plays a role in amantadine resistance, although all HA amino acids that participate in drug resistance still remain to be characterized. Our finding reveals that sequence analysis of the transmembrane domain of M2 protein may not adequately identify all drug-resistant variants.
authors: The D. I. Ivanovsky Institute of Virology, 16 Gamaleya Street, 123098 Moscow, Russia.|Division of Virology, Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Natalia A
authors: NA
authors: Ilyushina
authors: The D. I. Ivanovsky Institute of Virology, 16 Gamaleya Street, 123098 Moscow, Russia.|Division of Virology, Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Elena A
authors: EA
authors: Govorkova
authors: Division of Virology, Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Charles J
authors: CJ
authors: Russell
authors: Division of Virology, Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Erich
authors: E
authors: Hoffmann
authors: Department of Pathology, University of Tennessee, Memphis, TN 38105, USA.|Division of Virology, Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Robert G
authors: RG
authors: Webster
mesh_terms: D000547:Amantadine / Q000494:pharmacology* / Q000627:therapeutic use; D019943:Amino Acid Substitution; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use; D001769:Blood / Q000821:virology; D001921:Brain / Q000821:virology; D002460:Cell Line; D002642:Chick Embryo; D004195:Disease Models, Animal; D004285:Dogs; D024882:Drug Resistance, Viral / Q000235:genetics; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000502:physiology*; D053126:Influenza A Virus, H7N7 Subtype / Q000187:drug effects* / Q000502:physiology*; D008168:Lung / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D016297:Mutagenesis, Site-Directed; D009976:Orthomyxoviridae Infections / Q000188:drug therapy / Q000821:virology; D013154:Spleen / Q000821:virology; D014763:Viral Matrix Proteins / Q000235:genetics / Q000502:physiology
chemical_list: D000998:Antiviral Agents; D019267:Hemagglutinin Glycoproteins, Influenza Virus; C031540:M-protein, influenza virus; D014763:Viral Matrix Proteins; C109963:hemagglutinin, avian influenza A virus; D000547:Amantadine