Activation-dependent expression of the blood group-related lewis Y antigen on peripheral blood granulocytes

The expression of the difucosyl-lactosamine type 2 oligosaccharide Lewis Y (LeY) on peripheral blood cells was investigated. As assessed by the reactivity with the mouse anti-LeY monoclonal antibody (mAb) ABL 364 among circulating blood cells, the expression of the LeY oligosaccharide was uniquely restricted to granulocytes. Although the density of LeY expressed on resting granulocytes was weak, in vitro activation of granulocytes with fMLP induced a rapid and pronounced increase in granulocyte LeY expression. Analysis of CEA-related glycoproteins immunoprecipitated with anti-CD66 mAbs followed by immunoblotting with mAb ABL 364 showed that granulocyte LeY is attached to members of the CD66 cluster, in particular to the 160/90 kD glycoprotein recognized by anti-CD66 mAb CBL/gran 10. The activation-associated increase in LeY attached to CD66 adhesion molecules implicates a role of the LeY determinant in the cytoadhesive properties of granulocytes.