AUTOIMMUNE MRL MICE EXPRESS HIGH-AFFINITY IGG2B MONOCLONAL AUTOANTIBODIES TO HEPARIN

Heparin and heparan sulfate are related glycosaminoglycans which demon strate high-affinity interactions with a number of proteins, including antithrombin III. The immunogenicity of heparin has been reported pre viously employing heparin-protein conjugates as immunogens and as anti gens in solid-phase assays. Previous studies also demonstrate that ant i-heparin antibodies play a role in autoimmune diseases including syst emic lupus and anti-phospholipid syndrome and in patients who receive heparin for therapeutic purposes. In the current study, we investigate d the expression of monoclonal anti-heparin antibodies in nonimmunized , autoimmune MRL/lpr/lpr++ mice employing a liquid-phase radioimmunoas say. The K-d Of monoclonal IgG2b autoantibodies for heparin was approx imately 10(-8) M. Anti-heparin antibodies were precipitating, and were not polyreactive. The IgG monoclonal antibodies described in this stu dy represent an immunological instance of a specific, high-affinity he parin-protein interaction. (C) 1996 Academic Press, Inc.