Development of monoclonal antibodies to rabbit ocular mucin

Monoclonal antibodies against rabbit ocular mucin (ROM) and porcine stomach mucin (PSM) were developed to explore the biosynthesis and functional significance of ocular mucin. A nitrocellulose-based dot enzyme-linked immunosorbent assay (ELISA) was developed for hybridoma screening and mucin quantitation. The sensitivity was found to be at the level of 1 ng mucin per dot, which was about 1000 times more sensitive than that of our previously-reported histochemical method. Both anti-ROM and anti-PSM antibodies demonstrated specific bindings to rabbit conjunctival goblet cells and apical surface mucin of conjunctival epithelium by immunofluorescent and peroxidase-anti-peroxidase studies. These antibodies also showed specific bindings to ocular mucin and goblet cells of human conjunctiva on the impression cytology specimens obtained from normal subjects. These results indicate that these mucin-specific monoclonal antibodies can be used as a marker for goblet cell differentiation and as a probe to measure mucin content in the tear film and ocular surface. Selective loss of goblet cells and mucin deficiency were noted in impression cytology specimens of patients with various mucin-deficient disorders. This information indicates the potential application of these antibodies to study various ocular surface disorders characterized by alterations in goblet cell differentiation and mucin biosynthesis.