Molecular changes associated with adaptation of human influenza A virus in embryonated chicken eggs.
Failure to isolate A/Fujian/411/2002 (H3N2) in embryonated chicken eggs resulted in its absence from the 2003/2004 vaccine. We analyzed the adaptation of this virus in eggs during serial passages in the amniotic then allantoic cavities. Amniotic passage allowed the virus to grow in the allantoic cavity. During adaptation, 6 amino acid substitutions occurred: 4 in HA (G186V, S219F, V226I, V309I) and 2 in NA (E119Q, Q136K). These substitutions allowed binding to SAalpha2,3Gal- and SAalpha2,6Gal-containing receptors, conferred SAalpha2,3Gal specificity, and preserved antigenicity. Two HA substitutions (G186V, V226I) were sufficient to improve growth. Changing 2 NA residues (E119Q, Q136K) did not improve growth, and adaptation did not result in the HA changes H183L, D188Y, and V226A found by others. These findings suggest that viral adaptation in eggs involves multiple strategies. Vaccine manufacture will benefit from increased understanding of adaptation and strategies to improve human influenza A virus replication in eggs.
Division of Virology, Department of Infectious Diseases, Mail Stop 330, St. Jude Children's Research Hospital, and Integrated Program in Biomedical Sciences, The University of Tennessee Health Science Center, Memphis, TN 38163, USA.
Linda
L
Widjaja
Natalia
N
Ilyushina
Robert G
RG
Webster
Richard J
RJ
Webby
D000222:Adaptation, Physiological / Q000502:physiology*; D019943:Amino Acid Substitution; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics / Q000378:metabolism; D002642:Chick Embryo / Q000821:virology*; D015967:Gene Expression Regulation, Viral; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D011487:Protein Conformation; D016865:Reassortant Viruses; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication
D000956:Antigens, Viral; D014764:Viral Proteins