Marozin S, Gregory V, Cameron K, Bennett M, Valette M, Aymard M, Foni E, Barigazzi G, Lin Y, Hay A
National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK1.
Université Lyon 1, Laboratory of Virology, 8 Avenue Rockefeller, 69373 Lyon Cedex 08, France2.
J Gen Virol. 2002 Apr;83(Pt 4):735-745. doi: 10.1099/0022-1317-83-4-735.
Three subtypes of influenza A viruses, H1N1, H1N2 and H3N2, co-evolve in pigs in Europe. H1N2 viruses isolated from pigs in France and Italy since 1997 were closely related to the H1N2 viruses which emerged in the UK in 1994. In particular, the close relationship of the neuraminidases (NAs) of these viruses to the NA of a previous UK H3N2 swine virus indicated that they had not acquired the NA from H3N2 swine viruses circulating in continental Europe. Moreover, antigenic and genetic heterogeneity among the H1N2 viruses appeared to be due in part to multiple introductions of viruses from the UK. On the other hand, comparisons of internal gene sequences indicated genetic exchange between the H1N2 viruses and co-circulating H1N1 and/or H3N2 subtypes. Most genes of the earlier (1997-1998) H1N2 isolates were more closely related to those of a contemporary French H1N1 isolate, whereas the genes of later (1999-2000) isolates, including the HAs of some H1N2 viruses, were closely related to those of a distinct H1N1 antigenic variant which emerged in France in 1999. In contrast, an H3N2 virus isolated in France in 1999 was closely related antigenically and genetically to contemporary human A/Sydney/5/97-like viruses. These studies reveal interesting parallels between genetic and antigenic drift of H1N1 viruses in pig and human populations, and provide further examples of the contribution of genetic reassortment to the antigenic and genetic diversity of swine influenza viruses and the importance of the complement of internal genes in the evolution of epizootic strains.
甲型流感病毒的三种亚型，H1N1、H1N2和H3N2，在欧洲的猪群中共同进化。自1997年以来在法国和意大利猪群中分离出的H1N2病毒与1994年在英国出现的H1N2病毒密切相关。特别是，这些病毒的神经氨酸酶（NA）与之前英国H3N2猪病毒的NA密切相关，这表明它们并非从在欧洲大陆传播的H3N2猪病毒获得NA。此外，H1N2病毒之间的抗原性和基因异质性似乎部分归因于来自英国的病毒的多次引入。另一方面，内部基因序列的比较表明H1N2病毒与同时流行的H1N1和/或H3N2亚型之间存在基因交换。早期（1997 - 1998年）H1N2分离株的大多数基因与当代法国H1N1分离株的基因关系更密切，而后期（1999 - 2000年）分离株的基因，包括一些H1N2病毒的血凝素（HA），与1999年在法国出现的一种独特的H1N1抗原变异株的基因密切相关。相比之下，1999年在法国分离出的一株H3N2病毒在抗原性和基因上与当代人类A/悉尼/5/97样病毒密切相关。这些研究揭示了猪和人群中H1N1病毒的基因和抗原漂移之间有趣的相似之处，并提供了进一步的例子，说明基因重排在猪流感病毒的抗原性和基因多样性中的作用以及内部基因组成在流行毒株进化中的重要性。
