核、膜蛋白的基因能抑制禽类流感病毒及其重组株的繁殖

对人流感病毒A/Udorn/72(H_3N_2)株与禽类流感病毒A/Mallard/NY/78/(H_2N_2)重组后的重组株分析表明,仅含禽类病毒的核蛋白(NP)或膜蛋白(M)的RNA片段的重组株,在松鼠猴的呼吸道繁殖是受限制的。另外。仅有禽类的RNAl和NS基因的重组株(Clone 12)在松鼠猴的气管内的繁殖也明显受限制,而只具有其中一个基因的Clone 9, Clone 2, 则限制就不明显。由此表明,禽类流感病毒的NP和M基因在宿主范围的繁殖限制中起主要作用,而RNAI和SN基因的结合,同样起着繁殖受限制作用。

Nucleoprotein and Membrane Protein Genes Responsible for Restriction of Replication of Influenza A/Mallard/ NY/78 Virus and Its Reassortants in Respiratory Tract of Squirrel Monkeys

An avian influenza A virus, A/Mallard/NY/6750/78(H2N2), was restricted in replication in respiratory tract of squirrel monkeys. Avian-human influenza A reassortant viruses possessing the six RNA segments coding for non-surface proteins ( internal genes ) of this avian virus were as restricted in replication in squirrel monkeys as their avian influenza parent. These findings indicated that restriction of replication of avian influenza virus is a function of one or more of its internal genes. To investigate which of the avian influenza genes was responsible for restricted replication in respiratory tract of primates, reassortant viruses were produced that contained human influenza virus surface antigens from the A/Udorn/72 (H3N2) virus and one or more of the internal genes derived from the avian influenza virus parent. Avian-human reassortant influenza A viruses containing only nucleoprotein ( NP ) or matrix ( M ) protein RNA segment from the avian influenza virus parent were as restricted in their growth as that containing one of the six avian influenza internal genes. In addition, an avian-human influenza reassortant virus possessing only avian RNA 1 and NS genes ( which by themselves do not specify restricted replication) manifested a significant reduction of virus replication in trachea of squirrel monkey, Thus, the avian NP and M genes appear to play a major role in the host range restriction exhibited by A/Mallard/78 virus and its reassortants, but the combination of RNA 1 and NS genes also contributes to restriction of replication.