SUPPRESSION OF HUMAN CORNEAL EPITHELIAL PROLIFERATION WITH BREAST-CARCINOMA IMMUNOTOXIN

We examined the effects of the immunotoxin 260F9 Mab-recombinant ricin A (developed against human breast carcinoma) on proliferating and con fluent human corneal epithelium (HCE) cells in vitro. HCE cells derive d from explants of discarded human donor corneoscleral rims were estab lished as proliferating and confluent cell cultures, and were exposed continuously for 7 days to immunotoxin. Final cell counts at day 7, an d thymidine uptake measured at days 1 and 7 postexposure, showed >95% suppression of proliferating cells at an immunotoxin concentration of 10 ng/ml, with confluent HCE cells relatively unaffected. This immunot oxin may prove useful in treatment of proliferative ocular epithelial diseases such as epithelial downgrowth or squamous cell carcinoma of t he ocular surface.