title: Prominence of gamma delta T cells in the ruminant immune system.
abstract: The lymphoid systems of sheep and cattle contain a large number of gamma delta T cells, in striking contrast to the lymphoid systems of humans and mice. In neonatal animals particularly, these cells comprise the predominant fraction of T cells in the blood. Here Wayne Hein and Charles Mackay discuss what is currently known about the ontogeny, phenotype, tissue distribution and function of gamma delta T cells in ruminants. There are a number of interesting molecular features that characterize ruminant gamma delta T cells, but these do not entirely explain the high frequency of use of the gamma delta T-cell receptor in these animals. Studies on sheep, cattle or other animals that preferentially use gamma delta T cells should provide insights into the biological significance of the existence of two distinct forms of the T-cell receptor.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: W R
authors.initials: WR
authors.lastname: Hein
authors.forename: C R
authors.initials: CR
authors.lastname: Mackay
mesh_terms: D000818:Animals; D002417:Cattle; D008221:Lymphoid Tissue / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta; D012756:Sheep; D013045:Species Specificity; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology
chemical_list: D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta