Unilineage megakaryocytic proliferation and differentiation of purified hematopoietic progenitors in serum-free liquid culture.

摘要: Cellular and molecular analysis of megakaryocytopoiesis has been hampered thus far by the lack pure abundant megakaryocyte (MK) cell populations. In this study, hematopoietic progenitor cells (HPCs), stringently purified from peripheral blood, were induced to megakaryocytic differentiation/maturation in serum-free liquid suspension culture treated with a growth factor cocktail (interleukin-3 [IL-3], c-kit ligand, IL-6) and/or recombinant mpl ligand (mpIL). particular, (1) 40% MK population, ie, 4 x 10(4) at day 0 generated 2 10(5) terminal maturation; (2) further addition mpIL increased purity level 80% final yield MKs; (3) treatment alone resulted 97% 99% mild increase number (to 1.5 cells). mpIL-supplemented culture, morphological evaluation indicated presence putative mononuclear precursors then mature polynucleated platelet- forming MKs, peaking days 5 12, respectively. Membrane phenotype showed gradual decrease CD34+ HPCs, coupled an inverse MK-specific antigens (eg, CD61/62/42b) starting before detection morphology analysis. situ hybridization expression von Willebrand gene both MKs. Furthermore, MKs synthesize secrete low but significant amounts IL-6 granulocyte- macrophage colony-stimulating factor. Comparative studies performed on bone marrow CD34+/38hi or CD34+/38lo stimulated alone. Both populations highly enriched progeny (62% 93% 12 respectively) either little no proliferation. conclusion, blood HPC differentiation system allows for relatively large “pure” providing vitro experimental tool dissect cellular basis megakaryocytopoiesis.