Monoclonal antibodies against developmentally regulated corneal antigens.

The chick cornea is comprised of three cellular layers, each associated with a discrete extracellular matrix. The absence of specific markers for these cellular and acellular components has made it difficult to investigate the cell-cell and cell-matrix interactions which occur during development of this organ. We have approached this problem by producing monoclonal antibodies to species-specific, developmentally regulated antigens of the chick cornea. By immunofluorescence staining patterns the antibodies fall into three distinct groups. One group is directed against the corneal extracellular matrix. At 9 days of embryonic development staining by these antibodies is detected at the endothelial surface (in Descemet's membrane), and in the posterior part of the stroma. During development it progresses anteriorly throughout the entire width of the corneal stroma and Bowman's membrane until, by 14 days, it is found in all three specialized extracellular matrices of the cornea. Throughout most of development these antibodies do not recognize any other ocular or nonocular tissue examined. Late in development they begin to lightly stain nerve bundles. A second group of antibodies is highly selective for the corneal epithelial cell layer. These begin to stain at 12 to 13 days of development and cause very bright fluorescence by 14 days. A third group stains the extracellular matrix of the cornea in a manner spatially and temporally identical to that of the first group, but in addition recognizes certain basement membranes. The possible relationship of the antigens recognized by these groups of antibodies to developmental events occurring at the time of their appearance, and the potential use of all three antibody groups in studying corneal development are discussed.