USE OF ANTIBODIES DIRECTED AGAINST BLOOD-GROUP SUBSTANCES AND LECTINSTOGETHER WITH GLYCOSIDASE DIGESTION TO STUDY THE COMPOSITION AND CELLULAR-DISTRIBUTION OF GLYCOPROTEINS IN THE LARGE HUMAN AIRWAYS

Some 30 lectins in combination with glycosidase digestion and immunohi stochemistry with 5 antibodies directed against antigens of the ABO an d Lewis blood group systems were used to analyse the distribution and synthesis of glycoconjugates in the epithelium oi the large airways in man. Both mucous gland cells and goblet cells were labelled by 12 of 30 lectins and by the antibodies, dependent on the ABO; Lewis, and sec retor status. The corresponding binding patterns of the serous gland c ells differed markedly from those of goblet and mucous gland cells and in general were not dependent on the ABO, Lewis, and secretor status. After digestion with neuraminidase and fucosidase, binding of soy bea n agglutinin and peanut agglutinin to goblet and mucous gland cells wa s increased. Binding of peanut agglutinin to serous gland cells was st ronger only after the digestion with neuraminidase. Digestion with O-g lycosidase after the use of neuraminidase or fucosidase resulted in a decrease of peanut agglutinin binding to goblet and mucous gland cells . The present results show that the secretory products of goblet and m ucous gland cells on the one hand and those of serous cells on the oth er differ considerably with respect to their terminal glycosylation. T he glycosyltransferases coded by genes of the ABO and Lewis blood grou p and secretor systems are active only in goblet and mucous gland cell s, resulting in the presence of the corresponding antigens. Precursor substances of blood group antigens types 1, 2, and 3 are found only in these cell types. In serous gland cells, blood group systems do not i nfluence the glycosylation of glycoproteins. The results of the digest ion with O-glycosidase indicates the presence of O-glycosylation in mu cous gland and goblet cells, but not in serous gland cells.