title: Characterization of porcine T lymphocytes and their immune response against viral antigens.
abstract: T lymphocytes play a central role in the antigen-specific immune response against various pathogens. To detect and to characterize porcine T lymphocytes, monoclonal antibodies (mAb) against leukocyte differentiation antigens had been raised and classified for their specificity. Analyses of porcine T lymphocytes with specific mAb against CD4 and CD8 differentiation antigens revealed differences in the composition of the porcine T-lymphocyte population compared to other species. In addition to the known subpopulations, CD4+CD8- T helper cells and CD4-CD8+ cytolytic T lymphocytes, extra-thymic CD4+CD8+ T lymphocytes and a substantial proportion of CD2-CD4-CD8- T cell receptor (TcR)-gamma delta+ T cells could be detected in swine. Functional analyses of porcine T-lymphocyte subpopulations revealed the existence of two T-helper cell fractions with the phenotype CD4+CD8- and CD4+CD8+. Both were reactive in primary immune responses in vitro, whereas only cells derived from the CD4+CD8+ T-helper-cell subpopulation were able to respond to recall antigen in a secondary immune response. With regard to T lymphocytes with cytolytic activities, two subsets within the CD4-CD8+ T-cell subpopulation could be defined by the expression of CD6 differentiation antigens: CD6- cells which showed spontaneous cytolytic activity and CD6+ MHC I-restricted cytolytic T lymphocytes including virus-specific cytolytic T lymphocytes. These results enable now a detailed view into the porcine T-cell population and the reactivity of specific T cells involved in the porcine immune response against pathogens. Furthermore this knowledge offers the possibility to investigate specific interactions of porcine T lymphocytes with virus-specific epitopes during vaccination and viral infections.
authors.affiliation: Institut für Immunologie, Bundesforschungsanstalt für Viruskrankheiten der Tiere, Tübingen, Germany. armin.saalmueller@tue.bfav.de
authors.forename: A
authors.initials: A
authors.lastname: Saalmüller
authors.forename: T
authors.initials: T
authors.lastname: Pauly
authors.forename: B J
authors.initials: BJ
authors.lastname: Höhlich
authors.forename: E
authors.initials: E
authors.lastname: Pfaff
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D001709:Biotechnology; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D010641:Phenotype; D013552:Swine; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D015704:CD4 Antigens; D016827:CD8 Antigens