title: Differential expression of bovine MHC class II antigens identified by monoclonal antibodies.
abstract: Four monoclonal antibodies (mAbs), UC-A4, UC-D3, UC-H9, and IL-A21, specific for bovine major histocompatibility complex class II proteins are described. Sequential immunoprecipitation experiments using biotin-labeled peripheral blood mononuclear cells suggested, but did not conclusively establish, that each of these antibodies recognized a different epitope. The epitope identified by IL-A21 appeared to be common to all of the class II proteins precipitated by the four mAbs, and UC-D3 and UC-H9 each appeared to react with distinct epitopes on separate subsets of these class II proteins. Monoclonal antibody UC-A4 appeared to identify an epitope on a subset of the class II molecules identified by UC-H9. Differences found in the expression by lymphoid cells of class II proteins identified by the four mAbs were indicative of each mAb recognizing a different epitope. UC-H9 and IL-A21 class II proteins were detected on all surface immunoglobulin (S'Ig) positive cells in peripheral blood, but UC-A4 and UC-D3 class II proteins were not. Expression of UC-A4 class II proteins, detected at low density on a strikingly reduced number of S'Ig+ cells from the blood of some bovine leukosis virus-infected cattle, could be increased by culturing these B cells with lipopolysaccharide. All peripheral blood monocytes expressed UC-H9 and IL-A21 class II proteins, but only a proportion of monocytes expressed detectable UC-A4 and UC-D3 class II proteins. Almost all mitogen-stimulated BoCD4+ and BoCD8+ T cells expressed UC-H9 and IL-A21 class II proteins, whereas fewer stimulated T cells of both subsets expressed UC-A4 and UC-D3 class II proteins. All gamma/delta receptor (gamma/delta R) T cells expressed UC-D3, UC-H9, and IL-A21 class II proteins, but no cells (of gamma/delta R+ or CD4+/CD2+ phenotype) from gamma/delta R+ T cell-enriched cultures expressed UC-A4 class II proteins.
authors.affiliation: Department of Veterinary Microbiology and Immunology, University of California, Davis 95616.
authors.forename: B C
authors.initials: BC
authors.lastname: Taylor
authors.forename: K Y
authors.initials: KY
authors.lastname: Choi
authors.forename: R J
authors.initials: RJ
authors.lastname: Scibienski
authors.forename: P F
authors.initials: PF
authors.lastname: Moore
authors.forename: J L
authors.initials: JL
authors.lastname: Stott
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis* / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000648:ultrastructure; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002417:Cattle; D002478:Cells, Cultured; D000939:Epitopes / Q000276:immunology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D000949:Histocompatibility Antigens Class II / Q000032:analysis* / Q000276:immunology; D007150:Immunohistochemistry; D007962:Leukocytes / Q000166:cytology* / Q000276:immunology* / Q000648:ultrastructure; D008213:Lymphocyte Activation; D009000:Monocytes / Q000166:cytology / Q000276:immunology / Q000648:ultrastructure; D010641:Phenotype; D011233:Precipitin Tests; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000648:ultrastructure
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D016827:CD8 Antigens; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D016692:Receptors, Antigen, T-Cell, gamma-delta