title: New monoclonal antibodies in CD59: use for the analysis of peripheral blood cells from paroxysmal nocturnal haemoglobinuria (PNH) patients and for the quantitation of CD59 on normal and decay accelerating factor (DAF)-deficient erythrocytes.
abstract: CD59 is a widely expressed cell surface glycosylphosphatidylinositol (GPI)-linked glycoprotein which acts as an inhibitor of the assembly of the membrane attack complex of autologous complement. Four new monoclonal antibodies to CD59 (2/24, 1B2, BRIC 229, BRIC 257) are described. Competitive binding experiments using these antibodies, two known CD59 antibodies (MEM-43, YTH 53.1) and a previously described antibody LICR-LON-Fib75.1 demonstrated that all seven antibodies see related epitopes on human erythrocyte CD59. In common with other GPI-linked proteins, CD59 (as defined by antibody 2/24) was sensitive to treatment with phosphatidylinositol-specific phospholipase C (PI-PLC) on lymphocytes and monocytes but not on erythrocytes. Flow cytometric analysis using antibody 2/24 identified two populations (CD59 positive and CD59 deficient) of lymphocytes, monocytes and erythrocytes in peripheral blood from a patient with paroxysmal nocturnal haemoglobinuria (PNH). The abundance of CD59 on normal erythrocytes was determined as 21,000 copies/cell when radioiodinated BRIC 229 was used. Other CD59 antibodies gave values of 10,000 (IF5) and 15,000 (2/24) against the same target cells. Radioiodinated Fab fragments of BRIC 229 gave a value of 39,000 copies/cell. Erythrocytes from two individuals with a rare inherited deficiency of decay accelerating factor (DAF), known as the Inab phenotype, expressed normal levels of CD59.
authors.affiliation: Australian Red Cross Society, New South Wales Division, Blood Transfusion Service, Sydney.
authors.forename: A
authors.initials: A
authors.lastname: Fletcher
authors.forename: J A
authors.initials: JA
authors.lastname: Bryant
authors.forename: B
authors.initials: B
authors.lastname: Gardner
authors.forename: P A
authors.initials: PA
authors.lastname: Judson
authors.forename: F A
authors.initials: FA
authors.lastname: Spring
authors.forename: S F
authors.initials: SF
authors.lastname: Parsons
authors.forename: G
authors.initials: G
authors.lastname: Mallinson
authors.forename: D J
authors.initials: DJ
authors.lastname: Anstee
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology*; D018958:CD55 Antigens; D018957:CD59 Antigens; D002460:Cell Line; D000939:Epitopes / Q000187:drug effects; D004912:Erythrocytes / Q000276:immunology*; D006457:Hemoglobinuria, Paroxysmal / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D008562:Membrane Glycoproteins / Q000032:analysis / Q000276:immunology*; D008565:Membrane Proteins / Q000172:deficiency*; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018958:CD55 Antigens; D018957:CD59 Antigens; D000939:Epitopes; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase