title: Monoclonal antibodies against Caprine arthritis-encephalitis virus epitopes in the p28 and p55(gag) viral proteins.
abstract: The genome of the Caprine Arthritis-Encephalitis Virus (CAEV) encodes the polycistronic precursor protein p55(gag). Proteolytic cleavage of p55(gag) generates the viral core proteins. Some studies suggest that the CAEV p55(gag) protein contains epitopes or antigenic determinants for these core proteins. This work reinforces this hypothesis and demonstrates that monoclonal antibodies (MAbs) that are directed against the capsid protein (p28) of CAEV are also reactive against the precursor p55(gag) protein and the intermediate cleavage products, p44, p36 and p22. The major activity of the MAbs was directed against p28. The MAbF12 binding site in p28 was found to be a linear epitope with a structure that is stable after SDS treatment and remains unaltered after β-mercaptoethanol (β-ME) treatment. The MAbF12 binding site in the p55(gag), p36 and p22 proteins was found to be a linear epitope with cross-linked sulphide bonds. In conclusion, these findings suggest that the p28 epitope is presented differently from the epitope in the polycistronic precursor protein p55(gag). The highly immunogenic p28 contains a linear epitope that is detergent-stable and is not altered by β-ME treatment, whereas the p55(gag) epitope contains a linear epitope susceptible to denaturing agents.
authors.affiliation: Laboratory of Virology, Department of Biointeraction, Health Science Institute, Universidade Federal da Bahia, Av Reitor Miguel Calmon s/n Vale do Canela, Salvador, 40110-100 Bahia, Brazil.
authors.forename: Camila Fonseca Lopes
authors.initials: CF
authors.lastname: Brandão
authors.forename: Gubio Soares
authors.initials: GS
authors.lastname: Campos
authors.forename: Ana Carolina Requião
authors.initials: AC
authors.lastname: Silva
authors.forename: Juliana Alves
authors.initials: JA
authors.lastname: Torres
authors.forename: Dellane Martins
authors.initials: DM
authors.lastname: Tigre
authors.forename: Silvia Ines
authors.initials: SI
authors.lastname: Sardi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000914:Antibodies, Viral / Q000276:immunology*; D016088:Arthritis-Encephalitis Virus, Caprine / Q000276:immunology*; D036022:Capsid Proteins / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D005260:Female; D015683:Gene Products, gag / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D036022:Capsid Proteins; D000939:Epitopes; D015683:Gene Products, gag