title: Abnormal patterns of equine leucocyte differentiation antigen expression in severe combined immunodeficiency foals suggests the phenotype of normal equine natural killer cells.
abstract: Severe combined immunodeficiency (SCID) is a fatal autosommal disease of Arabian horses that leads to failure of maturation of T- and B-lymphocyte populations, although natural killer (NK) cells are unaffected. Thymic and lymph node tissues from two foals suffering from SCID were examined in an immunohistological study using a panel of monoclonal antibodies recognising equine leucocyte differentiation antigens. In both foals, the majority of cells in lymphoid tissues had an EqCD3-EqCD4-EqCD8+ phenotype, although rare EqCD3+ cells were also detected. The EqCD3-EqCD4-EqCD8+ cells may represent an abnormal lymphocyte differentiation product resulting from the SCID defect, or alternatively may be a normal equine NK cell population. We suggest that the evidence favours the latter proposal, and that equine NK cells in normal horses therefore may be identified by an EqCD3-EqCD8+ phenotype. The implications for the nature of the equine SCID defect are discussed.
authors.affiliation: Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Lunn
authors.forename: J T
authors.initials: JT
authors.lastname: McClure
authors.forename: C S
authors.initials: CS
authors.lastname: Schobert
authors.forename: M A
authors.initials: MA
authors.lastname: Holmes
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis*; D006734:Horse Diseases / Q000276:immunology*; D006736:Horses; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology; D008643:Mesentery; D016511:Severe Combined Immunodeficiency / Q000276:immunology* / Q000662:veterinary*; D013950:Thymus Gland / Q000276:immunology
chemical_list: D000943:Antigens, Differentiation