ABSTRACT
The genomic region coding for the antigenic structure responsible for the induction of neutralizing antibodies was localized in the central variable region of the VP2 gene by comparing the nucleotide sequence of five escape mutants derived from the standard infectious bursal disease virus strain Cu-1. Exchange of a single amino acid at one of the prominent hydrophilic parts of this region proved to be sufficient for altering the neutralizing properties. The reactivity of neutralizing antibodies with peptides expressed in vitro encompassing both hydrophilic areas suggests that the entire variable region is engaged in the formation of this conformation-dependent antigenic site. VP2-specific, non-neutralizing monoclonal antibodies directed against the sequence-dependent epitope of the serotype I strain Cu-1 and the serotype II strain 23/82 cross-reacted with peptides located towards the carboxy terminus of VP2; no reaction occurred with peptides derived from the amino-terminal side adjacent to the variable region.
Subject(s)
Antigens, Viral/genetics , Capsid/genetics , Epitopes/genetics , Genes, Viral/genetics , Infectious bursal disease virus/genetics , Mutation/genetics , Amino Acid Sequence , Antibodies, Viral , Capsid/immunology , Capsid Proteins , DNA, Viral/genetics , Infectious bursal disease virus/immunology , Molecular Sequence Data , Precipitin Tests , Protein BiosynthesisABSTRACT
The present knowledge of genome organisation, structural basis of pathogenicity and antigenicity of infectious bursal disease virus (IBDV) are briefly reviewed. The current situation of IBDV infection in various countries is stated and recommendations for improved vaccination schemes are given.
