CD164 - A novel sialomucin on CD34(+) cells

Hematopoiesis in adult bone marrow is a tightly regulated process involving interactions between cytokine and adhesion receptors on hematopoietic prog enitor cells and their cognate ligands in the immediate microenvironment. T hese interactions control hematopoietic stem cell self-renewal, quiescence, commitment and migration. Recently, sialomucins have assumed some importan ce in hematopoiesis, with six of these receptors, CD34, PSGL-1, CD43, PCLP, CD45RA and CD164, having been identified on primitive hematopoietic pre cu rsor cells and/or their associated stromal/endothelial elements. This artic le reviews the cloning, expression and function of the recently identified sialomucin, CD164, which is highly expressed by primitive hematopoietic pro genitor cells. The CD164 receptor is implicated in mediating or regulating hematopoietic precursor cell adhesion to stroma, and may serve as a potent negative regulator of hematopoietic progenitor cell proliferation.