Expansion of human NOD/SCID-repopulating cells by stem cell factor, Flk2/Flt3 ligand, thrombopoietin, IL-6, and soluble IL-6 receptor.

:Here, we demonstrate a significant ex vivo expansion of human hematopoietic stem cells capable of repopulating in NOD/SCID mice. Using a combination of stem cell factor (SCF), Flk2/Flt3 ligand (FL), thrombopoietin (TPO), and a complex of IL-6 and soluble IL-6 receptor (IL-6/sIL-6R), we cultured cord blood CD34(+) cells for 7 days and transplanted these cells into NOD/SCID mice. Bone marrow engraftment was judged successful when recipient animals contained measurable numbers of human CD45(+) cells 10-12 weeks after transplantation. When cells were cultured with SCF+FL+TPO+IL-6/sIL-6R, 13 of 16 recipients were successfully engrafted, and CD45(+) cells represented 11.5% of bone marrow cells in engrafted recipients. Cells cultured with a subset of these factors were less efficiently engrafted, both as measured by frequency of successful transplantations and prevalence of CD45(+) cells. In animals receiving cells cultured with all 4 factors, human CD45(+) cells represented various lineages, including a large number of CD34(+) cells. The proportion of CD45(+) cells in recipient marrow was 10 times higher in animals receiving these cultured cells than in those receiving comparable numbers of fresh CD34(+) cells, and the expansion rate was estimated at 4.2-fold by a limiting dilution method. Addition of IL-3 to the cytokine combination abrogated the repopulating ability of the expanded cells. The present study may provide a novel culture method for the expansion of human transplantable hematopoietic stem cells suitable for clinical applications.

Ueda T ，Tsuji K ，Yoshino H ，Ebihara Y ，Yagasaki H ，Hisakawa H ，Mitsui T ，Manabe A ，Tanaka R ，Kobayashi K ，Ito M ，Yasukawa K ，Nakahata T ... -  《JOURNAL OF CLINICAL INVESTIGATION》

Signal through gp130 activated by soluble interleukin (IL)-6 receptor (R) and IL-6 or IL-6R/IL-6 fusion protein enhances ex vivo expansion of human peripheral blood-derived hematopoietic progenitors.

Kimura T ，Wang J ，Minamiguchi H ，Fujiki H ，Harada S ，Okuda K ，Kaneko H ，Yokota S ，Yasukawa K ，Abe T ，Sonoda Y ... -  《STEM CELLS》

Differential kinetics of primitive hematopoietic cells assayed in vitro and in vivo during serum-free suspension culture of CD34+ blood progenitor cells.

Möbest D ，Goan SR ，Junghahn I ，Winkler J ，Fichtner I ，Hermann M ，Becker M ，de Lima-Hahn E ，Henschler R ... -  《STEM CELLS》

Differentiation of hematopoietic progenitor cells towards the myeloid and B-lymphoid lineage by hepatocyte growth factor (HGF) and thrombopoietin (TPO) together with early acting cytokines.

Grassinger J ，Mueller G ，Zaiss M ，Kunz-Schughart LA ，Andreesen R ，Hennemann B ... -  《EUROPEAN JOURNAL OF HAEMATOLOGY》

Role of different medium and growth factors on placental blood stem cell expansion: an in vitro and in vivo study.

Berger M ，Fagioli F ，Piacibello W ，Sanavio F ，Mareschi K ，Biasin E ，Bruno S ，Gammaitoni L ，Gunetti M ，Nesi F ，Madon E ，Aglietta M ... -  《BONE MARROW TRANSPLANTATION》