Immunogold Localization of Type VII Collagen in the Adhesion Complex of Pathologic Cornea

ABSTRACT

Type VII collagen is one of the major structural components of the corneal epithelial adhesion complex. Using the immunogold technique combined with indirect immunofluorescence analysis, the fine structural distribution of type VII collagen was studied in the corneas obtained from 5 enucleated hyman eyes (age range, 1-77 years) including one pathologic cornea from graft rejection. The findings on normal cornea corroborated the results from previous studies. In pathologic cornea from graft rejection, type VII collagen antibodies generated linear and irregular patchy fluorescence staining along the epithelial-stromal interface and immunogold binding to type VII collagen mainly occurred within the undulating lamina densa, more densealy distributed anchoring plaques and anchoring fibrils. The distribution of type VII collagen in pathologic human cornea from graft rejection is similar to normal human cornea. But, in pathologic cornea, type VII collagen is more densely distributed in superficial stroma and forms more extended anchoring network, which may be derived from the increased secretion of the type VII collagen due to the activated basal epithelial cell during healing process.