title: Serum and mucosal antibodies of infected foals recognized two distinct epitopes of VapA of Rhodococcus equi.
abstract: Virulence-associated protein A (VapA) of Rhodococcus equi has been proposed for use both as a vaccine and as a target for antibodies in immunotherapy and diagnostic tests. Epitope mapping of VapA allowed the identification of two B cell epitopes associated with R. equi pneumonia. The peptide NLQKDEPGRASDT was confirmed as an immunodominant N-terminal B cell epitope recognized by all sera from infected foals while VSFQYNAVGPYLNINFFDSS (C-terminal B cell epitope) was exclusively recognized by IgA from the tracheal aspirates. Moreover, specific antibodies produced against the VapA-specific peptide reacted with a major protein (approximately 20 kDa) from R. equi antigens separated by two-dimensional gel electrophoresis. The strong reactivity of mucosal IgA from infected foals with the conserved peptides might constitute an attractive target for diagnosis and vaccine.
authors.affiliation: AFSSA, Laboratoire d'Etudes et de Recherches en Pathologie Equine, IPC, 14430 Goustranville, Dozulé, France. s.taouji@dozule.afssa.fr
authors.forename: Saíd
authors.initials: S
authors.lastname: Taouji
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bréard
authors.forename: Alexis
authors.initials: A
authors.lastname: Peyret-Lacombe
authors.forename: Stéphane
authors.initials: S
authors.lastname: Pronost
authors.forename: Guillaume
authors.initials: G
authors.lastname: Fortier
authors.forename: Claire
authors.initials: C
authors.lastname: Collobert-Laugier
mesh_terms: D000193:Actinomycetales Infections / Q000276:immunology / Q000662:veterinary*; D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte; D006734:Horse Diseases / Q000276:immunology* / Q000382:microbiology; D006736:Horses; D016056:Immunodominant Epitopes; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology; D011817:Rabbits; D012137:Respiratory System / Q000276:immunology; D016929:Rhodococcus equi / Q000276:immunology*; D037521:Virulence Factors
chemical_list: D000914:Antibodies, Viral; D001426:Bacterial Proteins; D018985:Epitopes, B-Lymphocyte; D016056:Immunodominant Epitopes; D007071:Immunoglobulin A, Secretory; D008562:Membrane Glycoproteins; D010455:Peptides; D037521:Virulence Factors