FLOW-CYTOMETRY AND IMMUNOBLOTTING ANALYSIS OF MONOCLONAL-ANTIBODIES DIRECTED TO COMPLEMENT REGULATORY PROTEINS

A series of 18 monoclonal antibodies directed to complement regulatory proteins were investigated by flow cytometry and immunoblotting. Seve nteen antibodies are directed against a phosphatidyl inositol-linked g lycoprotein since they show a dual population of erythrocytes from a p aroxysmal nocturnal haemoglobinuria (PNH) patient. From this group, 6 antibodies revealed a 65-70 kDa band on immunoblots allowing their ide ntification as anti-DAF (Decay Accelerating Factor; CD55 antigen), and 11 bound to a 20 kDa molecule corresponding to MIRL (Membrane Inhibit or of Reactive lysis, CD59 antigen). One antibody revealed an homogene ous population from the PNH patient and bound to a 200 kDa band on imm unoblot that might corresponds to the CR1 (Complement Receptor type 1; CD35).