Presence of H Type 3/4 Chains of ABO Histo-blood Group System in Serous Cells of Human Submandibular Gland and Regulation of Their Expression by the Secretor Gene (FUT2)

SUMMARY We have investigated by immunochemistry the distribution of H Type 3/4 chains of the ABO histo-blood group system in human submandibular gland using a monoclonal anti-H MBr1 antibody specific for H Type 3/4 chains, and have found the expression of H Type 3/4 chains was mainly in the serous cells. Serous cells from secretors were stained by MBr1 but not by anti-A and anti-B antibodies, whereas serous cells from nonsecretors exhibited a negative reaction with MBr1. Mucous cells were not stained by MBr1. Only a few striated duct cells showed a weak reaction with anti-H MBr1. These results suggested that the H Type 3/4 chains were distributed predominantly in the serous cells of the human submandibular gland and that secretor Type a (1,2)fucosyltransferase (Se enzyme) controlled the synthesis of H Type 3/4 chains in vivo. Saliva also contained H Type 3/4 chains, which were controlled by the secretor gene ( FUT2 ). The differences in the distributions of H Type 1, H Type 2, and H Type 3/4 chains of the ABO histo blood group system in the submandibular gland are discussed. (J Histochem Cytochem 47:889‐894, 1999)