A distinct glycoform of CD44 is an L-selectin ligand on human hematopoietic cells

We previously have obtained operational evidence of a hematopoietic cell L- selectin ligand expressed on normal human hematopoietic cells and on leukem ic blasts. Using a technique developed in our laboratory for analyzing and identifying adhesion molecules, we show here that hematopoietic cell L-sele ctin ligand is a specialized glycoform of CD44. This L-selectin ligand acti vity of CD44 requires sialofucosylated N-linked glycans and is sulfation-in dependent. These data provide important insights on the structural biology of CD44 and reveal a role for this protein as an L-selectin ligand on human hematopoietic cells.