Suppressed expression of blood group B antigen and blood group galactosyltransferase in a preleukemic subject.
The B antigen activity was severely diminished in a patient's RBCs at the preleukemic stage prior to chemo- or radiotherapy. The amount of H sites of the patient's RBC membranes was found to be comparable to that of O RBC membranes. The activity of alpha (1----2) fucosyltransferase (H enzyme) was not severely decreased in the patient's plasma and bone marrow. However, the activity of alpha (1----3) galactosyltransferase (B enzyme), which converts H substance to B substance, was drastically reduced in the patient's bone marrow. Thus, the diminished B antigen in the patient's RBCs was caused mainly by the blockage of conversion of the H substance to B substance. It is suggested that the viral oncogene linked to the ABO locus at q34 of chromosome No. 9 would occasionally suppress the expression of blood group A and B enzymes and A and B antigens.
D000017:ABO Blood-Group System; D001853:Bone Marrow / Q000201:enzymology; D004912:Erythrocytes / Q000276:immunology; D005700:Galactosyltransferases / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000201:enzymology; D006801:Humans; D007519:Isoantigens / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011289:Preleukemia / Q000097:blood* / Q000201:enzymology / Q000276:immunology
D000017:ABO Blood-Group System; D007519:Isoantigens; D005700:Galactosyltransferases