Distribution of H type 1-4 chains of the ABO(H) system in different cell types of human respiratory epithelium

We used three anti-H monoclonal antibodies (MAbs) specific for H Type 1, H Type 2, and H Type 3/4 antigens to investigate the distribution of H Type I -H Type 4 chains of the ABO(H) histo-blood group in the human respiratory s ystem. Strong staining of H Type 1 chain and weak staining of H Type 2 chai n were observed in mucous cells of submucosal glands of bronchial epitheliu m, which were dependent on the secretor status. No H Type 3/4 chains were d etected in mucous cells. Serous cells of submucosal glands of respiratory s ystem showed no staining by three anti-H antibodies. H Type 1 and H Type 3/ 4 antigens were detected heterogeneously in apical surfaces of bronchial ep ithelium from secretors but not from nonsecretors. In contrast, basal cells of bronchial epithelium expressed H Type 2 irrespective of the secretor st atus, probably regulated by the H gene. Some alveolar Type II cells contain ed only H Types 3/4, which were dependent on the secretor status, whereas a lveolar Type I cells had no H antigens. Our results indicated that differen t cell types in respiratory epithelium expressed different types of carbohy drate chains of histoblood group antigens under the control of the H or the Se gene.