RESUMEN
The human influenza A virus (H3N2) has been the predominant influenza strain since 1992, and one property of this virus is non-agglutination of chicken erythrocytes [Ch(-) virus]. The Ch(-) virus in our study was able to acquire chicken hemagglutination [Ch(+)] by trypsin passage but not by chymotrypsin passage. Moreover, the trypsin-passaged Ch(+) viruses reacquired the Ch(-) property after a further chymotrypsin passage. In particular, genetic analysis showed no evidence of mutations in the hemagglutinin (HA) gene during either trypsin or chymotrypsin passages: the only differences found were in the HA cleavage sites between the trypsin-passaged virus and the chymotrypsin-passaged virus as determined by the N-terminal amino acid sequence. These results suggested that protease-dependent differences at the viral HA cleavage site, rather than genetic mutations, are likely to have a significant effect on the viral ability to produce chicken hemagglutination.
Asunto(s)
Quimotripsina/metabolismo , Hemaglutinación/fisiología , Hemaglutininas/química , Hemaglutininas/metabolismo , Subtipo H3N2 del Virus de la Influenza A/química , Subtipo H3N2 del Virus de la Influenza A/fisiología , Tripsina/metabolismo , Animales , Pollos , Quimotripsina/farmacología , Perros , Eritrocitos/química , Eritrocitos/efectos de los fármacos , Eritrocitos/virología , Cobayas , Hemaglutinación/efectos de los fármacos , Células de Riñón Canino Madin Darby , Pase Seriado , Tripsina/farmacologíaRESUMEN
The isolation of an H5N1 influenza A virus from a tree sparrow (Passer montanus) captured in East Java, Indonesia in 2010 is reported here. Its hemagglutinin and neuraminidase were genetically similar to those of human isolates from 2006-2007 in Indonesia. The finding of a tree sparrow H5N1 virus that possesses genetically similar surface molecules to those of human viruses highlights the importance of monitoring resident wild birds, as well as migratory birds, for pandemic preparedness.