Fucosylated Thomsen-Friedenreich antigen in alpha-anomeric configuration in human gastric surface epithelia: an allogeneic carbohydrate antigen possibly controlled by the Se gene.

Human gastric surface epithelial cells display the ABH blood group antigens with the core structure of N-acetyllactosamine (NAcLc). Their expression is under the control of the secretor gene Se. The Thomsen-Friedenreich (T)-antigen (Gal beta 1-3GalNAc) is another core structure of the ABH antigens. We examined the gastric surface epithelial expression of T- and alpha 1-2 fucosylated T (FucT) histochemically with peanut agglutinin (PNA) and monoclonal antibody (MAb) MBr1, respectively. Eight of 24 individuals exhibited the PNA-reactive antigen (i.e., T-expressers) and others the MBr1-reactive antigen (i.e., FucT-expressers). alpha-L-fucosidase digestion of the FucT-positive tissues and beta-galactosidase digestion of the T-positive tissues, respectively, made them reactive with PNA and the antibody specific for GalNAc alpha-O-Ser/Thr. There was a remarkable correlation among reactivities with MBr1, Ulex europaeus lectin 1 (UEA1), and anti-Leb MAb CO-431. ABH blood group status had no correlation with this expression. We conclude that human gastric surface epithelial cells constitutionally synthesize T in alpha configuration (i.e., Gal beta 1-3GalNAc alpha-O-Ser/Thr) and that it was alpha 1-2 fucosylated only in the FucT-expressers. alpha 1-2 fucosylation of T is suggested to be regulated by the Se gene.