PRODUCTION AND CHARACTERISATION OF MONOCLONAL ANTIBODIES AGAINST HEPARIN Deborah

To complement the studies using MAbs to AT III and because of the reported ability of heparin to modulate several aspects of the cell-mediated immune response, we have prepared two mouse monoclonal antibodies (MAbs) to porcine mucosal heparin.

MAb 25/15 is an IgGl and MAb 26/7 is an IgM. Both MAbs have iso-electric points between pH5.85 and 6.55. The MAbs recognise porcine and bovine mucosal heparin and rat mast cell heparin. Heparins with both high and low affinitiesfor antithrombin III (ATIII) bound both MAbs but neither MAb altered the binding of heparin to AT III. These antibodies did not recognise other proteoglycans (chondroitin sulphate types A, B and C, keratan sulphate and hyaluronic acid) with the exception of heparan sulphate, (the cellular equivalent of heparin) and Arte- paron (Luitpold-Werk, Munchen; a synthetically poly- sulphated chondriotin sulphate), in competition and solid-phasebinding assays. Dextransulphate(Pharmacia) was also recognised by these MAbs. Cross-reactivity with Arteparon and dextran sulphate indicate that charged sulphate goups on the mucopolysaccharides may be importantBfor MAb binding. The Mabs described may beuseful probes for endogenous heparin at the cellular and tissue level and may allow further investigation of the many biological activitiesof heparin