Binding of four lectins to normal human oral mucosa

The binding affinity of four lectins to normal human buccal mucosa was studied. Biopsies (diameter 2 mm) were obtained from eight healthy volunteers. Cryostat cut sections (4 micron thick) were stained with the following FITC-conjugated lectins: Ulex europaeus I (UEA I) soybean (SBA), peanut (PNA) and Lens culinarius (LCA). The specificity of the staining was controlled using the respective sugars. UEA I stained the epithelial intercellular spaces from the upper stratum (str.) spinosum to str. superficiale. Vascular endothelium in the connective tissue was also stained by UEA I. SBA stained the intercellular spaces of str. spinosum, whereas PNA stained both str. spinosum and str. superficiale. LCA stained the basement membrane and the intercellular areas of str. basale and str. spinosum. The elastic fibers of connective tissue were probably also stained by LCA. The lack of suprabasal staining by SBA and PNA indicates accelerated cell turnover as compared to normal human epidermis.