Hematopoietic stem cells

The adequate production of blood cells is maintained by a set of immature h ematopoietic stem cells (HSC) located in the bone marrow after birth. HSC a re able to reconstitute the hematopoietic system in disease-related bone ma rrow failure and bone marrow aplasia. Nowadays, HSC cells can be mobilized from the bone marrow into the peripheral blood using hematopoietic cytokine s, allowing a convenient harvest of these cells for clinical transplantatio n. This review outlines the development of the hematopoietic system in the embryo and in adults and the characterization, enumeration, purification an d ex vivo expansion of HSC for clinical use. Future directions include the genetic manipulation of HSC and the identification/expansion of bone marrow -derived stem cells capable of generating non-hematopoietic tissues. (C) 20 01 Editions scientifiques et medicales Elsevier SAS.