title: Identification and expression of a gene encoding an epitope that induces hemagglutination inhibition antibody to Avibacterium paragallinarum serovar A.
abstract: The aims of this study were the identification, cloning, and expression of a genetic region encoding an epitope that induces hemagglutination inhibition (HI) antibody against Avibacterium paragallinarum serovar A and an evaluation of the recombinant protein for immunogenicity in chickens. Although two monoclonal antibodies (MAbs) with HI activity, designated S24-951 and S7-1716-5C, were generated in this study, no reactive proteins with both MAbs were identified by Western blot analysis. A gene fragment of 5157 bp, designated hpa5. 1, was cloned from genomic DNA, and a recombinant protein expressed by hpa5.1, designated HPA5.1, reacted with both MAbs on dot-blot analysis. HPA5.1 showed no hemagglutinating activity, but significantly absorbed HI antibodies in the chicken immune serum. Analysis using a series of deletion mutants prepared from hpa5.1 indicated that a 4.8 kbp gene in hpa5.1 is essential for the expression epitope recognized by MAb S24-951. In addition, chickens immunized once with HPA5.1 showed a high protection rate with sufficient HI antibody titers against challenge exposure with a virulent strain of A. paragallinarum serovar A strain 221. These results show that hpa5. I1 is responsible for the expression of an epitope that induces HI antibody, and HPA5.1 might be a candidate for the development of a new vaccine against avian infectious coryza caused by A. paragallinarum serovar A.
authors.affiliation: Kyoto Biken Laboratories, Inc., 24-16 Makishima-cho, Uji-shi, Kyoto, 611-0041, Japan.
authors.forename: Taichi
authors.initials: T
authors.lastname: Noro
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yaguchi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Amimoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Oishi
mesh_terms: D000818:Animals; D000906:Antibodies / Q000235:genetics / Q000378:metabolism*; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines / Q000276:immunology; D002645:Chickens / Q000276:immunology / Q000378:metabolism*; D003001:Cloning, Molecular; D000939:Epitopes / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006384:Hemagglutination; D006385:Hemagglutination Inhibition Tests; D051379:Mice; D008807:Mice, Inbred BALB C; D015661:Pasteurellaceae / Q000502:physiology*; D016871:Pasteurellaceae Infections / Q000517:prevention & control / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms
chemical_list: D000906:Antibodies; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D000939:Epitopes