Nerome K, Kanegae Y, Shortridge K F, Sugita S, Ishida M
Department of Virology I, National Institute of Health, Tokyo, Japan.
J Gen Virol. 1995 Mar;76 ( Pt 3):613-24. doi: 10.1099/0022-1317-76-3-613.
From immunological and phylogenetic analyses of H3 influenza viruses isolated from pigs and ducks in the People's Republic of China (China), Hong Kong, Taiwan and Japan, between 1968 and 1982, we arrived at the following conclusions. The H3 haemagglutinin and N2 neuraminidase genes from swine isolates can be segregated into four mammalian lineages, including: (i) the earliest human strains; (ii) early swine strains including Hong Kong isolates from 1976-1977; (iii) an intermediate strain between the early swine and recent human strains; and (iv) recent human strains. In this study we found an unusual swine strain (sw/Hong Kong/127/82) belonging to the third lineage which behaved like those of the early swine-like lineage in the haemagglutination inhibition test; but neuraminidase inhibition profiles with monoclonal antibodies indicated that this virus is related to late human strains. On the basis of pairwise comparisons of complete or partial nucleotide sequences the genes encoding the three polymerase proteins (PB2, PB1, PA), the nucleoprotein, the membrane protein and possibly the nonstructural proteins of sw/Hong Kong/127/82 are of the swine H1N1 lineage, whereas genes encoding the two surface glycoproteins belong to the human H3N2 lineage. In contrast, all RNA segments of one swine isolate (sw/Hong Kong/81/78) are similar to those of recent human H3N2 viruses. This study indicated that frequent interspecies infections between human and swine hosts appeared to occur during 1976-82. Although the evolutionary rates of human (0.0122/site/year), swine (0.0127/site/year) and avian (0.0193/site/year) virus genes are similar when based upon synonymous substitutions, nonsynonymous substitutions indicated that viral genes derived from human and swine viruses evolved about three times faster (0.0026-0.0027/site/year) than those of avian viruses (0.0008/site/year). Furthermore, the evolutionary mechanism by which human and swine H3 haemagglutinin genes evolve at a similar rate, based on nonsynonymous substitutions, appeared to be quite different from previous evidence which showed that human H1 haemagglutinin genes evolved three times faster than those of swine viruses. However, comparison of the number of nonsynonymous substitutions in the antigenic sites (A-E) of haemagglutinin molecules demonstrated that swine viruses evolve at a rate that is about one fifth to one tenth that of human viruses, reflecting the conservative nature of the antigenic structure in the former.
通过对1968年至1982年间从中华人民共和国（中国）、香港、台湾和日本的猪和鸭中分离出的H3流感病毒进行免疫学和系统发育分析，我们得出了以下结论。猪分离株的H3血凝素和N2神经氨酸酶基因可分为四个哺乳动物谱系，包括：（i）最早的人类毒株；（ii）早期猪毒株，包括1976 - 1977年香港的分离株；（iii）早期猪毒株和近期人类毒株之间的中间毒株；以及（iv）近期人类毒株。在本研究中，我们发现了一株属于第三谱系的不寻常猪毒株（sw/Hong Kong/127/82），它在血凝抑制试验中的表现类似于早期猪样谱系的毒株；但用单克隆抗体进行的神经氨酸酶抑制谱分析表明，该病毒与晚期人类毒株有关。基于完整或部分核苷酸序列的成对比较，编码三种聚合酶蛋白（PB2、PB1、PA）、核蛋白、膜蛋白以及可能的非结构蛋白的基因，sw/Hong Kong/127/82的这些基因属于猪H1N1谱系，而编码两种表面糖蛋白的基因属于人类H3N2谱系。相比之下，一株猪分离株（sw/Hong Kong/81/78）的所有RNA片段都与近期人类H3N2病毒的相似。这项研究表明，1976 - 1982年间人类和猪宿主之间频繁发生种间感染。尽管基于同义替换时，人类（0.0122/位点/年）、猪（0.0127/位点/年）和禽（0.0193/位点/年）病毒基因的进化速率相似，但非同义替换表明，源自人类和猪病毒的病毒基因进化速度（0.0026 - 0.0027/位点/年）比禽病毒（0.0008/位点/年）快约三倍。此外，基于非同义替换，人类和猪H3血凝素基因以相似速率进化的进化机制，似乎与之前显示人类H1血凝素基因进化速度比猪病毒快三倍的证据有很大不同。然而，对血凝素分子抗原位点（A - E）中非同义替换数量的比较表明，猪病毒的进化速率约为人类病毒的五分之一至十分之一，这反映了前者抗原结构的保守性。
