title: Monoclonal antibodies specific for canine CD4 and CD8 define functional T-lymphocyte subsets and high-density expression of CD4 by canine neutrophils.
abstract: The characteristics of canine homologues of CD4 and CD8, defined by murine monoclonal antibodies CA13.1E4 (IgG1) and CA9.JD3 (IgG2a) respectively, are described. These antibodies identify mutually exclusive subpopulations of non-B lymphocytes in peripheral lymphoid organs and blood. However, in thymus the antibodies defined populations of double-positive, double-negative and single-positive cells that showed a progressive maturation consistent with that described for CD4 and CD8 in other mammalian species. Furthermore, functional studies clearly associated cytotoxic effector cell function with the subpopulation reactive with CA9.JD3 (CD8). In contrast, proliferation stimulated by allogeneic cells and mitogens was more pronounced in the subpopulation reactive with CA13.1E4 (CD4). Cell and tissue distribution studies revealed that CA13.1E4 stained neutrophils with equivalent intensity to the staining of peripheral T cells. CA13.1E4 precipitated a 60 kD protein from the surface of T cells and highly purified neutrophils under both reducing and nonreducing conditions. CA9.JD3 precipitated a heterodimer of 32 kd and 36 kD under reducing conditions, and a 70 kD protein under non-reducing conditions. The expression of CD4 by canine neutrophils is without precedent in other mammalian species; the functional significance of neutrophil CD4 expression is puzzling in light of the current understanding of the functions of CD4 which include it's role as a receptor for nonpolymorphic regions of MHC class II molecules.
authors.affiliation: Department of Pathology, School of Veterinary Medicine, University of California, Davis.
authors.forename: P F
authors.initials: PF
authors.lastname: Moore
authors.forename: P V
authors.initials: PV
authors.lastname: Rossitto
authors.forename: D M
authors.initials: DM
authors.lastname: Danilenko
authors.forename: J J
authors.initials: JJ
authors.lastname: Wielenga
authors.forename: R F
authors.initials: RF
authors.lastname: Raff
authors.forename: E
authors.initials: E
authors.lastname: Severns
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000502:physiology; D000918:Antibody Specificity / Q000276:immunology*; D015704:CD4 Antigens / Q000032:analysis / Q000276:immunology*; D016827:CD8 Antigens / Q000032:analysis / Q000276:immunology*; D016923:Cell Death / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004285:Dogs; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D007942:Leukemia, Experimental / Q000276:immunology / Q000473:pathology; D015479:Leukemia, Myelomonocytic, Acute / Q000276:immunology / Q000473:pathology; D007962:Leukocytes / Q000276:immunology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009504:Neutrophils / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D011233:Precipitin Tests; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D016827:CD8 Antigens