PRODUCTION AND CHARACTERIZATION OF MONOCLONAL-ANTIBODIES AGAINST RAT TRACHEAL MUCINS

The objective of this study was to generate and characterize monoclona l antibodies against rat airway mucins, Therefore, it should serve as a useful tool in studying the regulation of airway mucins using variou s in vivo rat models that are currently available. As an antigen, we u sed a high molecular mass mucin preparation purified from the spent me dia of rat tracheal surface epithelial cells in primary culture. Seven monoclonal hybridomas were obtained, among which mAbRT03 showed the h ighest immunoreactivity against the mucin, All of the antibodies secre ted by these hybridomas recognized carbohydrate epitopes but not siali c acid residues, since their immunoreactivity was completely abolished by treatment of the mucin with 20 mM periodate but not with neuramini dase. Further characterization of mAbRT03 showed that (1) it belongs t o the IgM type, (2) it binds to high molecular mass mucins based on We stern blot, (3) it could indirectly immunoprecipitate rat airway mucin -and, as we know, this is the first demonstration of immunoprecipitati on of airway mucin with anti-mucin antibodies-(4) it binds to the lumi nal side of tracheal epithelium as well as some goblet cells based on immunohistochemistry, and (5) it also recognizes in vivo airway mucins from rats, but not from human nor hamsters, which have been purified from the airway lavage fluids. This is the first monoclonal antibody a gainst rat airway mucin, which has been developed against purified rat airway mucins, Therefore, mAbRT03 should be able to serve as an inval uable tool in studying the regulation of airway mucins using various i ntact rat models that are currently available.