Monoclonal antibodies: cell surface markers for canine keratinocytes

Plasma membranes were isolated from cultured canine keratinocytes by paraformaldehyde-induced membrane vesiculation. The isolated plasma membrane vesicles retained cell surface antigens (eg, a pemphigus vulgaris antigen). These membrane vesicles were used as an antigen source for the production of monoclonal antibodies. Eight antibodies that had specific reactivity to the cytoplasmic membrane of keratinocytes on frozen sections of canine esophagus were identified by use of an indirect immunoperoxidase method. The stratified squamous epithelium of the esophageal mucosa had 4 staining patterns. When applied to frozen sections of canine skin, lip, and tongue, the antibodies had different tissue specificities for differing stratified squamous epithelia. Using sodium dodecyl sulfate polyacrylamide-gel electrophoresis and the western blot technique, one of the antibodies was specific for a 60-kD cell surface molecule. Therefore, such monoclonal antibodies may be useful in defining heterogeneity between different stratified squamous epithelia, in identifying biologically important surface antigens, or in the diagnosis of tumors.