THE HOMING OF HEMATOPOIETIC STEM-CELLS TO THE BONE-MARROW

In this article, the author discusses some of the most notable aspects of the work of Mehdi Tavassoli and others on the homing of intravenou sly transplanted hematopoietic stem cells to the marrow. It is well-re cognized that homing of stem cells is a highly selective process, perh aps similar to the homing of lymphocytes to lympoid tissues, The natur e of the selectivity of stem cell homing is unclear, however, and may be mediated through a specific homing receptor or through a method of selective capture, retainment, or survival advantage afforded by the m arrow. In this article, the focus is on current research in the identi fication of a specific homing receptor, the potential regulation of su ch a receptor by cytokines, the homing phenomenon as a multi-step proc ess, and secondary adhesive interactions mediated by known adhesive mo lecules, These interactions may serve to strengthen the initial recogn ition and engraftment of stem cells within the hematopoietic compartme nt of the marrow.