文献类型： 外文期刊

作者： Brown, EG ¹ ; Liu, H ² ; Kit, LC ² ; Baird, S ² ; Nesrallah, M ² ;

作者机构： 1.Univ Ottawa, Dept Biochem Microbiol & Immunol, Ottawa, ON K1H 8M5, Canada

2.Univ Ottawa, Dept Biochem Microbiol & Immunol, Ottawa, ON K1H 8M5, Canada; Shandong Acad Agr Sci, Inst Poultry Sci, Shandong 250100, Peoples R China; Childrens Hosp Eastern Ontario, Res Inst, Solange Gautheir Karsh Mol Genet Lab, Ottawa, ON K1H 8L1, Canada

期刊名称：PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA （ 影响因子：11.205； 五年影响因子：12.291 ）

ISSN： 0027-8424

年卷期： 2001 年 98 卷 12 期

页码：

收录情况： SCI

摘要： The genetic basis for virulence in influenza virus is largely unknown. To explore the mutational basis for increased virulence in the lung, the H3N2 prototype clinical isolate, A/HK/1/68. was adapted to the mouse. Genomic sequencing provided the first demonstration, to our knowledge, that a group of 11 mutations can convert an avirulent virus to a virulent variant that can kill at a minimal dose. Thirteen of the 14 amino acid substitutions (93%) detected among clonal isolates were likely instrumental in adaptation because of their positive selection, location in functional regions, and/or independent occurrence in other virulent influenza viruses, Mutations in virulent variants repeatedly involved nuclear localization signals and sites of protein and RNA interaction, implicating them as novel modulators of virulence. Mouse-adapted variants with the same hemagglutinin mutations possessed different pH optima of fusion, indicating that fusion activity of hemagglutinin can be modulated by other viral genes. Experimental adaptation resulted in the selection of three mutations that were in common with the virulent human H5N1 isolate A/HK/156/97 and that may be instrumental in its extreme virulence. Analysis of viral adaptation by serial passage appears to provide the identification of biologically relevant mutations.