title: B-cell epitopes of the envelope glycoprotein of caprine arthritis-encephalitis virus and antibody response in infected goats.
abstract: Goats infected with caprine arthritis-encephalitis virus (CAEV) develop high titres of antibodies to Env. Not only is no consistent neutralizing response found but anti-Env antibodies have even been associated with disease in infected goats. To identify the continuous antigenic determinants involved in this atypical anti-Env response, we mapped CAEV-CO Env by screening an epitope expression library with infected goat sera. In addition to the four previously described epitopes, seven novel antigenic sites were identified, of which five were located on the surface (SU) and two in the transmembrane (TM) subunits of Env. The SU antibody-binding domains located in the variable regions of the C-terminal part of the molecule (SU3 to SU5) showed the strongest reactivity and induced a rapid seroconversion in six experimentally infected goats. However, the response to these immunodominant epitopes did not appear to be associated with any neutralizing activity. The pattern of serum reactivity of naturally infected goats with these epitopes was restricted, suggesting a type-specific reaction. Interestingly, the reactivity of peptides representing SU5 sequences derived from CAEV field isolates varied with the geographical and/or breeding origin of the animals. This suggests that peptides corresponding to the immunodominant SU epitopes may well be useful in the serotyping of CAEV isolates. Furthermore, the identification of the CAEV Env epitopes will permit us to functionally dissect the antibody response and to address the role of anti-Env antibodies either in the protection from or in the pathogenesis of CAEV infection.
authors.affiliation: Institute of Veterinary Virology, University of Berne, Länggass-Str. 122, CH-3012 Berne, Switzerland1.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bertoni
authors.affiliation: Institute of Veterinary Virology, University of Berne, Länggass-Str. 122, CH-3012 Berne, Switzerland1.
authors.forename: Christian
authors.initials: C
authors.lastname: Hertig
authors.affiliation: Institute of Veterinary Virology, University of Berne, Länggass-Str. 122, CH-3012 Berne, Switzerland1.
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Zahno
authors.affiliation: Institute of Veterinary Virology, University of Berne, Länggass-Str. 122, CH-3012 Berne, Switzerland1.
authors.forename: Hans-Rudolf
authors.initials: HR
authors.lastname: Vogt
authors.affiliation: Institute of Veterinary Virology, University of Berne, Länggass-Str. 122, CH-3012 Berne, Switzerland1.
authors.forename: Sophie
authors.initials: S
authors.lastname: Dufour
authors.affiliation: Institute of Veterinary Virology, University of Berne, Länggass-Str. 122, CH-3012 Berne, Switzerland1.
authors.forename: Pablo
authors.initials: P
authors.lastname: Cordano
authors.affiliation: Institute of Veterinary Virology, University of Berne, Länggass-Str. 122, CH-3012 Berne, Switzerland1.
authors.forename: Ernst
authors.initials: E
authors.lastname: Peterhans
authors.affiliation: Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington 99164-7040, USA2.
authors.forename: William P
authors.initials: WP
authors.lastname: Cheevers
authors.affiliation: Génétique des Virus (ICGM-CNRS UPR 0415), Institut Cochin de Génétique moléculaire, 75014 Paris, France3.
authors.forename: Pierre
authors.initials: P
authors.lastname: Sonigo
authors.affiliation: Génétique des Virus (ICGM-CNRS UPR 0415), Institut Cochin de Génétique moléculaire, 75014 Paris, France3.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Pancino
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000276:immunology*; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016088:Arthritis-Encephalitis Virus, Caprine / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D001665:Binding Sites; D015153:Blotting, Western; D003001:Cloning, Molecular; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D015686:Gene Products, env / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D006023:Glycoproteins; D006041:Goats / Q000276:immunology* / Q000821:virology*; D007106:Immune Sera / Q000096:biosynthesis / Q000276:immunology; D016056:Immunodominant Epitopes / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016180:Lentivirus Infections / Q000276:immunology* / Q000662:veterinary; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D019151:Peptide Library; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D013997:Time Factors; D014764:Viral Proteins
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; C412317:ENV protein, Caprine arthritis encephalitis virus; D018985:Epitopes, B-Lymphocyte; D015686:Gene Products, env; D006023:Glycoproteins; D007106:Immune Sera; D016056:Immunodominant Epitopes; D008565:Membrane Proteins; D019151:Peptide Library; D011994:Recombinant Proteins; D014764:Viral Proteins