Giuseppe
Emeritus
J Gen Virol.. [Epub ahead of print]
Alterations in receptor binding properties of swine influenza viruses of H1 subtype after isolation in embryonated chicken eggs.
Takemae N, Ruttanapumma R, Parchariyanon S, Yoneyama S, Hayashi T, Hiramatsu H, Sriwilaijaroen N, Uchida Y, Kondo S, Yagi H, Kato K, Suzuki Y, Saito T. - Thailand-Japan Zoonotic Diseases Collaboration Center; National Institute of Animal Health,Japan;
Alterations of the receptor binding properties of swine influenza A viruses (SIVs) during their isolation in embryonated chicken eggs have not been well studied. In this study, the receptor binding properties of classical H1 SIVs isolated solely in eggs or Madin-Darby canine kidney (MDCK) cells were examined. Sequencing analysis revealed substitutions of D190V/N or D225G in the HA molecules in egg-isolates, while MDCK-isolates retained identical HA genes with the original viruses presented in the clinical samples. Egg-isolates with substitution of either D190V/N or D225G had increased hemagglutinating activity for mouse and sheep erythrocytes but decreased activity for rabbit erythrocytes. Additionally, egg-isolates with D225G increased the hemagglutination activity of chicken erythrocytes. Direct binding assay using sialylglycopolymer, which possesses either a 5-N-acetylneuraminic acid (Neu5Ac) alpha2,6galactose (Gal) or a Neu5Acalpha2,3Gal linkage revealed that the egg-isolates used in this study showed higher binding activity to the Neu5Acalpha2,3Gal receptor than MDCK-isolates. Increased activity of the egg-isolates to the Neu5Acalpha2,3Gal receptor was also confirmed by hemagglutination assay with re-sialylated chicken erythrocytes by Galbeta1,3/4GlcNAcalpha2,3-sialyltransferase. These observations were reinforced by flow-cytometric and N-glycan analyses of the erythrocytes. The alpha2,3-linked sialic acids were dominantly expressed on the surfaces of mouse and sheep erythrocytes. Chicken erythrocytes expressed Neu5Acalpha2,3Gal more abundantly than Neu5Acalpha2,6Gal, and rabbit erythrocytes expressed both 5-N-glycolylneuraminic acid (Neu5Gc) alpha2,6Gal and Neu5Acalpha2,6Gal. Our results clearly demonstrated that classical H1 SIVs underwent alterations in receptor binding activity associated with an amino acid substitution in the HA protein during isolation and propagation in chicken embryonated eggs.
PMID: 20007353 [PubMed - as supplied by publisher]
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Alterations in receptor binding properties of swine influenza viruses of H1 subtype after isolation in embryonated chicken eggs.
Takemae N, Ruttanapumma R, Parchariyanon S, Yoneyama S, Hayashi T, Hiramatsu H, Sriwilaijaroen N, Uchida Y, Kondo S, Yagi H, Kato K, Suzuki Y, Saito T. - Thailand-Japan Zoonotic Diseases Collaboration Center; National Institute of Animal Health,Japan;
Alterations of the receptor binding properties of swine influenza A viruses (SIVs) during their isolation in embryonated chicken eggs have not been well studied. In this study, the receptor binding properties of classical H1 SIVs isolated solely in eggs or Madin-Darby canine kidney (MDCK) cells were examined. Sequencing analysis revealed substitutions of D190V/N or D225G in the HA molecules in egg-isolates, while MDCK-isolates retained identical HA genes with the original viruses presented in the clinical samples. Egg-isolates with substitution of either D190V/N or D225G had increased hemagglutinating activity for mouse and sheep erythrocytes but decreased activity for rabbit erythrocytes. Additionally, egg-isolates with D225G increased the hemagglutination activity of chicken erythrocytes. Direct binding assay using sialylglycopolymer, which possesses either a 5-N-acetylneuraminic acid (Neu5Ac) alpha2,6galactose (Gal) or a Neu5Acalpha2,3Gal linkage revealed that the egg-isolates used in this study showed higher binding activity to the Neu5Acalpha2,3Gal receptor than MDCK-isolates. Increased activity of the egg-isolates to the Neu5Acalpha2,3Gal receptor was also confirmed by hemagglutination assay with re-sialylated chicken erythrocytes by Galbeta1,3/4GlcNAcalpha2,3-sialyltransferase. These observations were reinforced by flow-cytometric and N-glycan analyses of the erythrocytes. The alpha2,3-linked sialic acids were dominantly expressed on the surfaces of mouse and sheep erythrocytes. Chicken erythrocytes expressed Neu5Acalpha2,3Gal more abundantly than Neu5Acalpha2,6Gal, and rabbit erythrocytes expressed both 5-N-glycolylneuraminic acid (Neu5Gc) alpha2,6Gal and Neu5Acalpha2,6Gal. Our results clearly demonstrated that classical H1 SIVs underwent alterations in receptor binding activity associated with an amino acid substitution in the HA protein during isolation and propagation in chicken embryonated eggs.
PMID: 20007353 [PubMed - as supplied by publisher]
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