Monoclonal Antibody Specific to Bovine Lens Epithelial Cell Membrane: Preparation of a Lens Epithelial Cell-Selective Immunotoxin

The lens opacity directly decreases visual acuity. To date, neither prophylactic nor pharmacologic treatments have been effective in stopping or decreasing lens opacity. Although extracapsular cataract extraction followed by intraocular lens insertion is considered to be an effective treatment, postoperative proliferation of lens epithelial cells (LECs) disturbs the vision again. In the present study a monoclonal antibody (MAb) directed against bovine LECs was generated. The MAb (XC3-2-B1H9) reacted specifically with the cell membrane of LECs. No other tissues in bovine eyes, such as the cornea, iris, ciliary body, choroid, retina, or the sclera, or any other major bovine organs, such as lung, liver, spleen, and kidney, were associated. The specificity of XC3-2-B1H9 was confirmed both by immunohistochemistry and by immunoblotting. This MAb cross-reacts with dog LECs. Based on immunoblot analysis, XC3-2-B1H9 recognizes the band with a Mr of about 160 kD of the water-insoluble fraction of LECs. The subclass of these MAbs is IgG₁ as determined by immunodiffusion. This MAb has the capacity to act as a component of an immunotoxin to target the LECs.