The Role of Eph Receptor Tyrosine Kinases and Ephrin Ligands in Hematopoietic Cell Development and Function

Abstract

The Eph receptor tyrosine kinases form the largest sub-family of the Receptor tyrosine kinases. Eph receptors interact with membrane bound ligands, termed ephrins. Eph-ephrin interactions have significant roles during mammalian development where they mediate such processes as cell adhesion and migration. Although Eph/ephrin expression is low in adult tissues evidence is accumulating which indicates that Eph and ephrins continue to play significant roles in postembryonic tissues. In this review we describe the current understanding of the function of Eph-ephrin signaling in human and mouse hematopoiesis. Ephs and ephrins have been shown to regulate the differentiation of hematopoietic cells, to direct lymphoid development as well as immune function. Whilst much still remains to be learned about the role of Ephephrin signaling in hematopoieis it is already clear that this system exerts important regulatory effects on differentiation, cell migration and effector function. The possibility that these molecules may be therapeutic targets is also discussed.