Interaction of late murine erythroid progenitors and stroma involves a recognition mechanism with fucosyl specificity

We have previously reported that the specific recognition and binding of murine hemopoietic progenitors spleen colony-forming units (CFU-S) and granulocyte-macrophage CFU (CFU-GM) to hemopoietic stroma is dependent upon a membrane recognition system with galactose and mannose specificities. By using synthetic neoglycoproteins with galactose, mannose, or fucose covalently bound to bovine serum albumin (BSA) in standard long-term bone marrow cultures (LTBMC), galactosyl-BSA (gal-BSA) and mannosyl-BSA (man-BSA) but not fucosyl-BSA (fuc-BSA) inhibited the binding of CFU-S and CFU-GM to the stromal layer. In the present work it was shown that binding of erythroid burst-forming units (BFU-E) to stroma in standard LTBMC is also inhibited by gal-BSA and man-BSA. We then studied a different system of LTBMC that favored erythropoiesis and allowed the production of erythroid CFU (CFU-E) for 4 weeks. In the presence of the fuc-BSA as well as gal-BSA and man-BSA, total cell production and CFU-E production were halted in the supernate as well as the adherent layer. These results indicate the presence of a fucosyl recognition system on the surface of the late erythroid precursors, CFU-E.