Association of food lectins with human oral epithelial cells in vivo.

The association of wheat germ agglutinin (WGA) and peanut agglutinin (PNA) with oral tissues after eating raw wheat-germ or raw peanuts, respectively, was determined. An indirect enzyme-linked immunoassay (ELIA) was used to detect WGA and PNA on epithelial cells. Buccal and tongue epithelial cells, and preparations of salivary sediment exhibited ELIA units of WGA and PNA significantly above background after eating 2--7 g of wheat-germ or 25 g of raw peanuts, respectively. Both lectins were detected also in preparations of salivary bacteria where they persisted for 1--6 h. Samples collected after eating raw wheat-germ and incubated with N-acetylglucosamine, or samples collected after eating raw peanuts and incubated with galactose had reduced ELIA units of lectin present. This suggests that the lectins were not non-specifically adsorbed or present as unbound food particles. Pretreating buccal epithelial cells in vitro with 25 micrograms of WGA increased the numbers of Streptococcus sanguis FC-1 cells which attached. Similarly, statistically significantly higher numbers of Strep. sanguis cells attached to buccal cells which were collected from donors after they had eaten raw wheat-germ compared to buccal cells collected prior to eating.