香港大學(xué)8月9日表示，該校李嘉誠醫(yī)學(xué)院研究人員連同海外合作伙伴的一項研究發(fā)現(xiàn)，如果兩個H1N1流感病毒的表面蛋白(血凝素以及神經(jīng)氨酸酶)達到活性的微妙平衡，可使病毒變得有能力經(jīng)飛沫傳播。
據(jù)介紹,，由于流感病毒在雪貂間傳播情況與人類最為相似，因此研究選取其作為動物模型,。研究人員選擇全球多種主要且具代表性的H1N1流感病毒放于雪貂間進行傳播試驗,，以評估這些病毒株經(jīng)由飛沫傳播的可能性。結(jié)果顯示,，這些代表性的病毒中,，唯有一種含歐亞型H1N1流感基質(zhì)蛋白基因的北美型流感重組病毒株具有少許的飛沫傳播能力。
研究人員利用流感病毒反向遺傳學(xué)(一種基因工程方法,，用于控制流感病毒基因的組合),，將2009年流行的H1N1流感病毒的神經(jīng)氨酸酶基因，加入這一株流感病毒,，所得出的新病毒株,，具有經(jīng)由飛沫傳播的能力,。
研究人員最終得出結(jié)論，流感病毒要經(jīng)由飛沫傳播,，病毒中的兩個病毒表面蛋白,，須達到活性的微妙平衡。
該研究報告已在美國國家科學(xué)院官方科學(xué)刊物美國《國家科學(xué)院院刊》（PNAS）中發(fā)表,。(生物谷 Bioon.com)
doi:10.1073/pnas.1111000108
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PMID:
Hemagglutinin–neuraminidase balance confers respiratory-droplet transmissibility of the pandemic H1N1 influenza virus in ferrets
Yen, Hui-Ling; Liang, Chi-Hui; Wu, Chung-Yi; Forrest, Heather L.; Ferguson, Angela; Choy, Ka-Tim; Jones, Jeremy; Dik-Yan Wong, Diana; Pak-Hang Cheung, Peter; Hsu, Che-Hsiung; Li, Olive T.; Yuen, Kit M.; Chan, Renee W. Y.; Poon, Leo L. M.; Chan, Michael C. W.; Nicholls, John M.; Krauss, Scott; Wong, Chi-Huey; Guan, Yi; Webster, Robert G.; Webby, Richard J.; Peiris, Malik
A novel reassortant derived from North American triple-reassortant (TRsw) and Eurasian swine (EAsw) influenza viruses acquiredsustained human-to-human transmissibility and caused the 2009 influenza pandemic. To identify molecular determinants thatallowed efficient transmission of the pandemic H1N1 virus among humans, we evaluated the direct-contact and respiratory-droplettransmissibility in ferrets of representative swine influenza viruses of different lineages obtained through a 13-y surveillanceprogram in southern China. Whereas all viruses studied were transmitted by direct contact with varying efficiency, respiratory-droplettransmissibility (albeit inefficient) was observed only in the TRsw-like A/swine/Hong Kong/915/04 (sw915) (H1N2) virus. Thesw915 virus had acquired the M gene derived from EAsw and differed from the gene constellation of the pandemic H1N1 virusby the neuraminidase (NA) gene alone. Glycan array analysis showed that pandemic H1N1 virus A/HK/415742/09 (HK415742) andsw915 possess similar receptor-binding specificity and affinity for α2,6-linked sialosides. Sw915 titers in differentiatednormal human bronchial epithelial cells and in ferret nasal washes were lower than those of HK415742. Introducing the NA frompandemic HK415742 into sw915 did not increase viral replication efficiency but increased respiratory-droplet transmissibility,despite a substantial amino acid difference between the two viruses. The NA of the pandemic HK415742 virus possessed significantlyhigher enzyme activity than that of sw915 or other swine influenza viruses. Our results suggest that a unique gene constellationand hemagglutinin–neuraminidase balance play a critical role in acquisition of efficient and sustained human-to-human transmissibility.
