Principaux enjeux de la production de cellules hématopoí étiques à partir de cellules souches embryonnaires humaines

Human embryonic stem cells (hESC) exhibit the remarkable property of being pluripotent: they theoretically can be differentiated in all cell types and have generated great hopes for regenerative medicine. Although hESCs were isolated only recently, our understanding of these cells has progressed very rapidly because of previous research on mouse ES cells. Clinical use of hESCs will require advances in the methods of isolation and culture in particular the elimination of components of animal origin. In addition, progress must be made to specifically direct differentiation toward useful cell types. Hematopoietic differentiation of hESC is now routinely obtained in numerous laboratories. Within hematopoiesis, erythropoiesis lineage seems to have the greatest potential for short-term clinical applications because of the relative simplicity of red blood cells and the fact that they do not express HLA antigens. However, hESC-derived erythrocytes obtained up to now exhibit, as revealed by morphological and globin analysis, developmentally immature phenotype similar to cells produced in the yolk sack or the early fetal liver that are probably not suitable for practical application. Clinical application will only become possible after a certain number of practical and fundamental issues are resolved.