title: Bovine γδ T cells are a major regulatory T cell subset.
abstract: In humans and mice, γδ T cells represent <5% of the total circulating lymphocytes. In contrast, the γδ T cell compartment in ruminants accounts for 15-60% of the total circulating mononuclear lymphocytes. Despite the existence of CD4(+)CD25(high) Foxp3(+) T cells in the bovine system, these are neither anergic nor suppressive. We present evidence showing that bovine γδ T cells are the major regulatory T cell subset in peripheral blood. These γδ T cells spontaneously secrete IL-10 and proliferate in response to IL-10, TGF-β, and contact with APCs. IL-10-expressing γδ T cells inhibit Ag-specific and nonspecific proliferation of CD4(+) and CD8(+) T cells in vitro. APC subsets expressing IL-10 and TFG-β regulate proliferation of γδ T cells producing IL-10. We propose that γδ T cells are a major regulatory T cell population in the bovine system.
authors.affiliation: The Pirbright Institute, Surrey GU24 0NF, United Kingdom; efrain.guzman@pirbright.ac.uk.
authors.forename: Efrain
authors.initials: E
authors.lastname: Guzman
authors.affiliation: The Roslin Institute University of Edinburgh, Midlothian EH259RG, United Kingdom; and.
authors.forename: Jayne
authors.initials: J
authors.lastname: Hope
authors.affiliation: The Pirbright Institute, Surrey GU24 0NF, United Kingdom;
authors.forename: Geraldine
authors.initials: G
authors.lastname: Taylor
authors.affiliation: Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom.
authors.forename: Adrian L
authors.initials: AL
authors.lastname: Smith
authors.affiliation: The Pirbright Institute, Surrey GU24 0NF, United Kingdom;
authors.forename: Carolina
authors.initials: C
authors.lastname: Cubillos-Zapata
authors.affiliation: The Pirbright Institute, Surrey GU24 0NF, United Kingdom;
authors.forename: Bryan
authors.initials: B
authors.lastname: Charleston
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology; D000941:Antigens / Q000276:immunology; D002417:Cattle; D049109:Cell Proliferation; D016753:Interleukin-10 / Q000276:immunology*; D051379:Mice; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology*
chemical_list: D000941:Antigens; D016692:Receptors, Antigen, T-Cell, gamma-delta; D016212:Transforming Growth Factor beta; D016753:Interleukin-10