甲型流感病毒H9N2亚型毒株血凝素基因特性的研究

目的　了解人甲型流感病毒H9N2亚型毒株的来源及从分子生物学角度来弄清不同宿主来源的H9N2亚型毒株间相互关系。方法　病毒在鸡胚中传代 ,从收获的尿囊液中提取病毒粒RNA ,通过逆转录合成cDNA。cDNA通过PCR进行扩增 ,接着PCR产物用纯化试剂盒进行纯化。而后 ,RNA序列测定是采用双脱氧链末端终止和克隆法。最后用MegAlign( 1.0 3版 )和Editseq( 3.69版 )软件进行种系发生学分析。结果　从中国所分离出的H9N2亚型毒株。它们的HA1与HA2间裂解部位的氨基酸序列均为R S S R ,除一株鸽病毒其HA蛋白分子上仅含 7个潜在的糖基化位点外 ,而其余的均含 8个。 6株H9N2毒株HA蛋白分子上氨基酸序列有 2 - 16个不同 ,这些不同分布在 2 4个不同的位点上。近来在中国同时流行着多种HA基因系的H9N2亚型毒株。结论　人甲型流感病毒H9N2亚型毒株可能性最大来自鸡的H9N2毒株 ,而不是来源于鸽的H9N2毒株。但 ,H9N2毒株是否具有人传人能力 ,至今仍不清楚。在中国同时流行着多种HA基因系的H9N2毒株。     

Characterization of hemagglutinin gene of influenza A virus subtype H9N2

Objective　To determine the origin of human influenza A (H9N2) virus and the relationship among H9N2 strains isolated from different hosts, on the basis of molecular biology. Methods　Viruses were passed in embryonated hen eggs, and virion RNA was extracted from allantoic fluid and reverse transcribed to synthesize cDNA. cDNA was amplified by PCR and the PCR product was purified with a purification kit. Afterwards RNA sequence analysis was performed by dideoxynucleotide chain termination and a cloning method. Finally, phylogenetic analysis of the sequencing data was performed with MegAlign (version 1.03) and Editseg (version 3.69) softwares. Results　The amino acid sequences at the cleavage site between HA1 and HA2 domains of H9N2 viruses isolated in China are R-S-S-R. One pigeon strain contains seven potential glycosylation sites on the HA protein molecule, while all others have eight. There are 2 to 15 differences of amino acid sequences distributed at 24 different positions on the HA protein molecules among six H9N2 viruses. The H9N2 viruses with multiple lineages of HA genes were co-circulating in China recently. Conclusion　The highest possibility is that human influenza A (H9N2) virus was derived from Chicken H9N2 virus, and not derived from pigeon H9N2 virus. However, it is still unknown whether the H9N2 virus could transmit from person to person. The H9N2 viruses with multiple lineages of HA genes are co-circulating in China.     

从我国人群中再次分离到H9N2亚型流感病毒

目的 了解分离流感病毒毒株表面抗原亚型和特性及其来源。方法 病毒通过ＭＤＣＫ细胞分离,用红细胞凝集抑制（ＨＩ）和神经氨酸酶抑制（ＮＩ）测定对病毒株表面抗原进行鉴定和特性分析,人血清中抗体测定采用ＨＩ和中和实验。对患者进行个」案调查。结果 分离物为甲型流感病毒Ｈ９Ｎ２亚型,属Ｇ９类似毒株,它的ＨＡ抗原特性与已经从人、鸡和鸽分离到的Ｈ９Ｎ２亚型毒株均有差异。患者恢复期血清对分离物的ＨＩ抗体滴度为４００     

流感病毒A/广州/333/99(H9N2)毒株基因组特性的研究

目的 了解一株再次从流感患儿中分离出禽H9N2流感毒株的基因组特性，并弄清它的来源。方法 病毒在鸡胚中传代，从收获的尿囊液中提取RNA，通过逆转录合成cDNA，cDNA用PCR扩增。PCR产物用纯化试剂盒纯化，接着做核苷酸序列测定，然后用Meg Align(Version 1.03)和Editseg(Version 3.69)软件进行基因进化树分析。结果 A／广州／333／99（H9N2）毒株的基因组属于禽流感病毒，但它明显不同于A／Duck/Hong Kong/Y439/97毒株。同时不含有任何人流感病毒基因节段，其基因组中有4个基因节段（分别编码HA、NA、NP和NS蛋白）来自G9毒株基因系，而其余4个基因节段（分别编码PB2、PB1、PA和M蛋白）来自G1毒株基因系。结论 A／广州／333／99（H9N2）病毒是G9和G1毒株通过基因重配而来的重配株，它最大可能性直接来自禽。进一步证实了禽H9N2毒株能感染人，同时首次证实了H9N2不同基因系毒株间，在自然界中也能发生基因重配。