ANTIGEN DISTORTION ALLOWS INFLUENZA-VIRUS TO ESCAPE NEUTRALIZATION

The structure of the hemagglutinin (HA) of a mutant influenza virus th at escapes neutralization by a nonclonal antibody shows that the mutat ion causes changes in HA structure which avoid and energetically less favorable conformation, However, the structure of the mutant HA-center -dot-Fab complex indicates that the antibody binds selectively to muta nt HA in a wild type-like distorted conformation. The association of a n antibody with a less favored HA conformation represents an alternati ve to previousness described mechanisms of escapes from neutralization by antibodies.