利用反向遗传技术对H_3N_2亚型流感病毒NA基因突变的研究

为了拯救出H3N2亚型流感病毒的重组新病毒,利用反向遗传学手段,8个质粒共同转染293T细胞,包装带有双点突变（第119位氨基酸由E突变为V,第222位氨基酸由I突变成L）、单点突变和野生型的流感病毒H3N2;在MDCK细胞中传代包装成的H3N2病毒。结果表明,野生流感病毒H3N2和其突变株包装成功,第119位氨基酸单点突变型滴度与野生型的相近,而第222位氨基酸单点突变和双突变型滴度要比野生型的低。本实验成功证明了H3N2神经氨酸酶上两个位点（第119和222位氨基酸）对病毒包装及复制起到关键的作用,且NA上第222位氨基酸相对于第119位氨基酸显得要更重要。

Use of Reverse Genetics Technology Responsible for H3N2 Influenza Virus NA Gene Mutations

In order to save the reorganization of a new virus of the H3N2 influenza virus,H3N2 wild type and three mutation type（E119D＋I222L,E119D and I222L） viruses were generated by reverse genetics;The reverse genetics viruses were stable after five passages in MDCK cells.Successfully generated H3N2 wild type and mutation type viruses;The wild type had a similar virus titer with the mutation type E119D;The virus titer of E119D＋I222L and I222L type were lower than the wild type.These results indicated that double mutation（E119D＋I222L） type H3N2 could induce a high level of oseltamivir resistance.NA and the first 222 amino acids compared to 119 amino acids seem to be more important.