Lateral and transmembrane redistribution of tissue-specific antigens in single cells and monolayers

Tissue-specific antigens in the membranes of corneal endothelial cells react with anti-tissue antibodies only in metabolically active monolayers and dispersed cells. After metabolic inhibition by exposure of these preparations to cold, the antigen-antibody complexes, like free antigens, undergo transmembrane redistribution leading to their internalization by the cells. This transmembrane redistribution is reversible and can be followed by using fluorescein-labeled antibodies. Reexpression of the complexes on the cell surfaces occurs after return from metabolic inhibition to metabolic activity. Dispersed corneal endothelial cells are also capable of lateral redistribution (capping) of the complexes although cells in monolayers do not share this capability. Capping in the dispersed cells occurs only at ambient temperatures and, because it results in shedding of the complexes, is irreversible. The data indicate that macromolecules in the membranes of cells organized in tissues are restricted in their movement as compared to the macromolecules of cells functioning in a dispersed state.