These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Comparative effects of retroviral-mediated gene transfer into primary human stromal cells of Flt3-ligand, interleukin 3 and GM-CSF on production of cord blood progenitor cells in long-term culture.
    Author: Balduini A, Braun SE, Cornetta K, Lyman S, Broxmeyer HE.
    Journal: Stem Cells; 1998; 16 Suppl 1():37-49. PubMed ID: 11012147.
    Abstract:
    The effects of different cytokines on growth of human cord blood CD34 cells was studied by performing long-term culture (LTC) with primary human stromal cells transduced with genes for either Flt3-ligand (L) (human transmembrane, murine soluble or murine membrane-bound forms), human interleukin 3 (IL-3) or human GM-CSF. Molecular analysis of genomic DNA from transduced stromal cells using neo-specific polymerase chain reaction demonstrated gene transfer of G418-selected stromal cell populations. Enzyme-linked immunosorbent assay and biological assays of conditioned media from transduced stromal cells indicated expression and release of soluble cytokines. Numbers of both immature and more mature progenitors (colony-forming unit-granulocyte, erythroid, macrophage, megakaryocyte; CFU-GEMM, BFU-E, CFU-GM) were increased threefold compared to control in the Flt3-L (transmembrane) LTC throughout five weeks of culture. IL-3 and GM-CSF feeders increased progenitor cell output also, but these effects were significantly lower than Flt3-L feeders. The two Flt3-L isoform engineered feeders, Ex6 (soluble isoform) and 5H (membrane-bound isoform), showed a decreased effect compared to the transmembrane Flt3-L feeders and, in particular, Ex6 feeders were similar to control feeders and 5H feeders were comparable to Flt3-L feeders only in the first two weeks of LTC. These results were apparent also by limiting dilution assays that showed a higher frequency of pre-CFU in the transmembrane Flt3-L feeders compared to control and the other cytokine feeders. Exogenous addition of soluble growth factors to suspension cultures without feeder layers, while superior to stromal feeders for short-term expansion of early progenitors, were inferior to the long-term maintenance/output on stromal feeders. Pre-CFU analysis supported these data. These results may be of some significance to understanding the actions of Flt3-L on blood cell production.
    [Abstract] [Full Text] [Related] [New Search]