Amino acids contributing to antigenic drift in the infectious bursal disease Birnavirus (IBDV).
We examined the effect of amino acids 222 and 254 on antigenicity of the variant Del-E strain of infectious bursal disease virus (IBDV). Using molecular epidemiology, we identified a virus designated as Del-E-222 that was identical to Del-E except for alanine at position 222. A second virus was generated using reverse genetics of the Del-E backbone to create Del-E-254 that contained an asparagine at amino acid 254. The Del-E-222 and Del-E-254 viruses were tested for their ability to escape neutralizing immunity provided by parenteral vaccination. The bursas from birds vaccinated with parental Del-E and challenged with Del-E-222 or Del-E-254 had macroscopic lesions typical of an IBDV infection, and their B-BW ratios were significantly smaller than the controls. Microscopic lesions included lymphocyte depletion and confirmed the ability of Del-E-222 and Del-E-254 to break through the immunity induced by the parental Del-E virus vaccination. Both mutations appear to be contributing to antigenic drift.
Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Avenue, Wooster, OH 44691, USA. Jackwood.2@osu.edu
Daral J
DJ
Jackwood
Susan E
SE
Sommer-Wagner
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000940:Antigenic Variation / Q000235:genetics* / Q000276:immunology; D000956:Antigens, Viral / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D018175:Birnaviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D002060:Bursa of Fabricius / Q000473:pathology / Q000821:virology; D002642:Chick Embryo; D002645:Chickens; D007243:Infectious bursal disease virus / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D008969:Molecular Sequence Data; D017354:Point Mutation; D011201:Poultry Diseases / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013047:Specific Pathogen-Free Organisms; D014611:Vaccination; D015678:Viral Structural Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology
D000914:Antibodies, Viral; D000956:Antigens, Viral; C082513:VP2 protein, infectious bursal disease virus; D015678:Viral Structural Proteins