Immunohistochemical differentiation of Schwann and epithelial basal lamina in the rabbit cornea.

Transmission electron microscopy has shown that at the point of entry of axons into corneal epithelium, Schwann cell lamina densa merges with lamina densa of epithelial origin. Staining properties and the thickness of lamina densa from these sources are similar. Immunostaining with monoclonal antibodies to laminin and type IV collagen revealed that while Schwann cell basal lamina fluoresced to both of these probes, epithelial basal lamina was visualized only with anti-laminin. Monoclonal antibodies to neurofilament protein (70 and 200 kDa) were used to visualize the neural tissue. Segments of the deep stromal and subepithelial innervation appeared similar to those seen following gold chloride impregnation. The results suggest that intercalation of lamina densa from these tissue sources and regulation of the production of basal lamina components by both the epithelial and the Schwann cells probably occur.