Saccharide residues in human gingiva as revealed with fluorochrome-coupled lectins

The histochemical binding of 16 fluorochrome-conjugated lectins to human marginal gingiva was investigated. Of a total of 14 galactose/N-acetylgalactosamine (Gal/GalNAc)-specific lectins, Dolichos biflorus (DBA), Helix pomatia (HPA), and Helix aspersa agglutinins (HAA) were blood group A-reactive whereas Griffonia simplicifolia I-B4 (GSA-I-B4) and Sophora japonica (SJA) agglutinins were blood group B-reactive. HPA, HAA and GSA-I-B4 bound to all suprabasal epithelial cells and to vascular endothelia in tissues with compatible blood groups and detected only upper epithelial cells in tissues lacking the respective blood group antigens. SJA, on the other hand, bound to suprabasal epithelial cells and to endothelial cells in specimens from blood group B, AB and A individuals. DBA gave a heterogeneous labeling of upper epithelial cells in blood group A, AB and B specimens but not in O specimens and did not react with endothelia in any of the tissue samples. DBA bound, instead, consistently to mast cells in gingival lamina propria. Of the other Gal/GalNAc-reactive lectins, 2 bound to suprabasal epithelial cells and 7 to all viable cell layers in gingival epithelium. The binding of these lectins was blood group-independent. Of the fucose-specific lectins, Ulex europaeus agglutinin I (UEA-I) gave an intense suprabasal cell membrane-type of epithelial fluorescence in blood group O specimens and a more diffuse staining in other specimens and recognized endothelial cells in a blood group-independent way. Anguilla anguilla agglutinin (AAA) gave a blood group-independent epithelial staining and bound heterogeneously to endothelial cells only in blood group O samples.(ABSTRACT TRUNCATED AT 250 WORDS)