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.
Jackwood
Daral J
DJ
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
Sommer-Wagner
Susan E
SE
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