biostudies-literatureGuzman EBiotechnology and Biological Sciences Research Council208-22https://www.ebi.ac.uk/biostudies/studies/S-EPMC4065783biostudies-literatureUnknown193(1)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.Journal of immunology (Baltimore, Md. : 1950)Bovine γδ T cells are a major regulatory T cell subset.PMC4065783BBS/E/I/00001373BBS/E/I/00001709BB/D001536/1BBS/E/D/20231762BB/F013590/1BB/H531135/1BBS/E/I/00001715Smith ALTaylor GCubillos-Zapata CGuzman EHope JCharleston BfalseBovine γδ T cells are a major regulatory T cell subset.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.2014-01-01T00:00:00Z2014 Jul2024-10-15T21:49:33.934Z2019-03-26T23:43:01ZS-EPMC40657832489072410.4049/jimmunol.1303398