title: Expression of gamma/delta T cell receptors in porcine thymus.
abstract: Swine possess an extraordinarily high number of T lymphocytes with the phenotype CD4-CD8- in peripheral blood as well as in lymphoid tissues. This subpopulation is subdivided into at least four subsets defined by the expression of CD2 and three biochemically distinct gamma/delta T cell receptors. The four subsets differ largely in their pattern of lymphoid homing in that CD2- subsets, historically referred to as null lymphocytes, predominate in the circulating pool, whereas CD2+ subsets are enriched in lymphoid tissues. Here we document the expression of all three types of gamma/delta T cell receptors by CD4-CD8- porcine thymocytes, which provides the first evidence for a thymic origination of all subsets of porcine gamma/delta T lymphocytes. The biochemical analysis shows that three distinct gamma-chains form disulfide-bonded cell surface heterodimers with a common delta-chain and that glycosylation of all chains is already completed within the thymus. Surprisingly, CD2- subsets, which are known to be enriched among thymic emigrants and which numerically predominate in peripheral blood, are underrepresented in the thymus, suggesting a high export rate.
authors.affiliation: Federal Research Center for Virus Diseases of Animals, Tübingen, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Hirt
authors.forename: A
authors.initials: A
authors.lastname: Saalmüller
authors.forename: M J
authors.initials: MJ
authors.lastname: Reddehase
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D018801:CD2 Antigens; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D010641:Phenotype; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis* / Q000302:isolation & purification; D011971:Receptors, Immunologic / Q000032:analysis; D013552:Swine; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000254:growth & development / Q000276:immunology / Q000378:metabolism*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D018801:CD2 Antigens; D015704:CD4 Antigens; D016827:CD8 Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011971:Receptors, Immunologic