INHIBITION OF PROLIFERATING LENS EPITHELIUM WITH ANTITRANSFERRIN RECEPTOR IMMUNOTOXIN

We investigated the effect of an antitransferrin receptor immunotoxin (454A12-rRA) on proliferating human and baboon lens epithelium in vitr o. Human and baboon lens epithelial cells grown in modified TC-199 med ium at 35 degrees Celsius in 7% CO2 were seeded in 24 well plates at a density of 17,500 cells/ml to 40,000 cells/ml. The cells were exposed to various concentrations of 454A12-rRA for seven days. The sensitivi ty of proliferating human lens epithelium to 454A12-rRA was dependent on the dose, with a 60% to 70% reduction in cell counts at immunotoxin concentrations of 100 ng/ml and above. The immunotoxin had no signifi cant effect on baboon lens epithelium in vitro, which suggests that it is specific for human tissue. By preventing the proliferation of huma n lens epithelial cells, immunotoxin 454A12-rRA may be useful in the m anagement of posterior capsule opacification after planned extracapsul ar cataract surgery.