Carbohydrate chains specific for blood group antigens in differentiation of human oral epithelium

Abstract

The distribution of A, B, and H blood group antigens and 2 blood group precursor carbohydrate chains (N-acetyl-lactosamine and lacto-N-triosyl-group) was examined in human buccal epithelium. The material included tissue from persons with blood group A, B, and O, 9 from each group. Six patients in each group were secretors of blood group antigens in the saliva and 3 were nonsecretors. The blood group antigens and the precursors of these were studied by an immunofluorescence staining technique. Murine monoclonal antibodies were used to identify H-antigen (type 2 chain) and for N-acetyl-lactosamine whereas polyclonal rabbit antibodies were used for lacto-N-triosyl-group. In all groups lacto-N-triosyl and N-acetyl-lactosamine were found on the cell membranes of basal and deeper spinous cells. The H-antigen was mainly present on cell membranes of the lower spinous cells. Only the basal cells above the connective tissue papilli showed cell membrane staining. Cytoplasmic staining in the upper two thirds of the epithelium was found with all antibodies when they were used in high concentrations. The A and B blood group antigens were detected by human blood group test sera and were found exclusively on the cell membranes of the spinous cells. The different sites of expression of A and B antigens and expression of H, and the precursor antigens N-acetyl-lactosamine and lacto-N-triosyl, suggest a stepwise building up of carbohydrates with blood group specificities during the differentiation of buccal epithelial cells.