title: Chicken macrophages and thrombocytes share a common cell surface antigen defined by a monoclonal antibody.
abstract: A monoclonal antibody (mAb), designated K1, reacted with a cell surface antigen shared on chicken macrophages and thrombocytes. By immunofluorescence staining, the mAb K1 was reactive with 31.8% of peripheral blood lymphocytes (PBL) separated on Histopaque. In contrast, only 3.2% of PBL separated by slow-speed centrifugation were K1 positive. This antibody did not react with B- or T-lymphocytes, as demonstrated by the very small percentage of positive cells in thymus, bursa and spleen. Furthermore, no staining was observed with avian T-cell (MDCC-RP1 and SK3) or B-cell (LSCC-RP9) lines. Adherent cells derived from PBL separated on Histopaque and cultured for 48 h in plastic cell culture dishes were 81.5% positive with K1. These cells were also 82.6% positive with an antibody detecting the major histocompatibility complex (MHC) Class II antigen in chickens, indicating that they were monocyte-derived macrophages. Sheep red blood cell phagocytosis by these cells could be demonstrated, further supporting their macrophage lineage. In addition, K1 stained virtually 100% of HD11 cells, a chicken macrophage cell line, as well as 86.7% of peritoneal exudate cells. Eighty five percent of plastic adherent cells from PBL collected after 2 h of adherence reacted with the mAb K1, but only 8% of these cells were MHC Class II positive. These cells were morphologically identified as thrombocytes. Immunoprecipitation analysis demonstrated that the K1-reactive antigen consisted of a heterodimer with constituent polypeptide chains of 135 kDa and 61-68 kDa.
authors.affiliation: Protozoan Diseases Laboratory, US Department of Agriculture, ARS, Beltsville, MD 20705.
authors.forename: B
authors.initials: B
authors.lastname: Kaspers
authors.forename: H S
authors.initials: HS
authors.lastname: Lillehoj
authors.forename: E P
authors.initials: EP
authors.lastname: Lillehoj
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D000954:Antigens, Surface / Q000096:biosynthesis*; D001792:Blood Platelets / Q000276:immunology*; D002060:Bursa of Fabricius / Q000276:immunology; D002460:Cell Line; D002645:Chickens / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005434:Flow Cytometry / Q000662:veterinary; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D006825:Hybridomas / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology; D016130:Immunophenotyping / Q000662:veterinary; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007074:Immunoglobulin G