Expansion and clinical use of hematopoietic progenitor cells in human marrow and peripheral blood

An ideal ex vivo product for infusion would contain sufficient numbers of Pluripotent Hematopoietic Stem Cell (PHSC), progenitors and precursor cells including megakaryocyte progenitors which would hopefully lead to a shortening of the time to hematological reconstitution following the administration of myelosuppressive or myeloablative therapy. Since PHSC have a greater proliferative and self-renewal capacity than any other cell in the hematopoietic hierarchy, the cellular output of such cell population would be anticipated to be greater than that observed with the use of more differentiated cell populations. Such grafts will be required to contain sufficient numbers of PHSC to ensure early, short term and delayed, sustained engraftment. Transfer of genetically modified somatic cells will likely play an important role in the treatment of a growing number diseases. Ex vivo expansion of mobilized peripheral blood hematopoietic cells obtained after one apheresis could be used to decrease the numbers of leukophereses performed, to expand the grafts of patients who do not mobilize adequately.