title: Neospora caninum antigens defined by antigen-dependent bovine CD4+ T cells.
abstract: Neosporosis is an important cause of pregnancy loss in cattle worldwide. The objective of the present study was to identify Neospora caninum antigens as vaccine candidates using antigen-specific, short-term CD4+ T cells established from N. caninum-immunized and -challenged cows. Whole N. caninum tachyzoite lysate was separated into 6 fractions by DEAE anion-exchange chromatography using high-pressure liquid chromatography (HPLC). The CD4+ T-cell proliferation assay results indicated that antigenic activity was associated with proteins from HPLC fractions 4-6, with fraction 5 exhibiting the highest antigenic activity. Also, SDS-PAGE analysis revealed a 16-kDa protein in fractions 4-6 that was recognized by anti-N. caninum antibodies. This 16-kDa protein was absent in other fractions, and it may be a target of a T-cell response in cattle. Further identification of immunogenic proteins of N. caninum may facilitate development of subunit vaccines against neosporosis.
authors.affiliation: Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705, USA. wtuo@anri.barc.usda.gov
authors.forename: Wenbin
authors.initials: W
authors.lastname: Tuo
authors.forename: Raymond H
authors.initials: RH
authors.lastname: Fetterer
authors.forename: William C
authors.initials: WC
authors.lastname: Davis
authors.forename: Mark C
authors.initials: MC
authors.lastname: Jenkins
authors.forename: J P
authors.initials: JP
authors.lastname: Dubey
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis / Q000276:immunology*; D015153:Blotting, Western / Q000662:veterinary; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000517:prevention & control; D002848:Chromatography, DEAE-Cellulose / Q000662:veterinary; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D003048:Coccidiosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005260:Female; D008213:Lymphocyte Activation; D018688:Neospora / Q000276:immunology*; D015800:Protozoan Proteins / Q000032:analysis / Q000276:immunology; D016052:Protozoan Vaccines / Q000276:immunology; D011817:Rabbits; D016622:Silver Staining / Q000662:veterinary; D022223:Vaccines, Subunit / Q000276:immunology
chemical_list: D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D022223:Vaccines, Subunit