Abstract
The S17 murine stromal cell line was infected with retroviral vectors encoding the v-src and c-src oncogenes and cells expressing high levels of either pp60v-src or pp60c-src were isolated. Long-term bone marrow cultures (LTBMCs) established with these different stromal cell lines showed that progenitor cells proliferated to a greater extent in cultures with stromal cells that over-expressed either c-src or v-src. An increase in the number of granulocytes, monocytes, and colony-forming units granulocyte-macrophage (CFU-GM) in the nonadherent cell population of LTBMCs prepared with S17/v-src or S17/c-src stromal cells was observed. Conditioned media from the S17/v-src and S17/c-src stromal cell lines stimulated the formation of CFU-GM in the absence of additional hematopoietic cell growth factors. Conditioned media from S17/v-src and S17/c-src stimulated proliferation of the granulocyte-macrophage colony-stimulating factor (GM-CSF)-responsive cell line FDCP-1 and this stimulation was inhibited by neutralizing antisera to murine GM-CSF. An increase in the concentration of GM-CSF was confirmed by enzyme-linked immunosorbent assay. No secretion of interleukin-1α (IL-1α) or tumor necrosis factor-α was detected by any of the stromal cell lines. There was no increase in the secretion of either CSF-1 or IL-6 by either S17/v-src or S17/c-src. The addition of 1 μg/mL monoclonal anti-GM-CSF antibody to LTBMCs caused a decrease in the number of nonadherent cells in cultures established with each of the different stromal cell lines. Northern blot analysis showed no difference in the level of GM-CSF RNA among the different stromal cell lines. These studies suggest that the increased proliferation of hematopoietic progenitor cells in LTBMCs with S17/v-src or S17/c-src cells may result from a posttranscriptional event that elevates production of GM-CSF by the S17/c-src and S17/v-src stromal cells.
Original language | English (US) |
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Pages (from-to) | 3079-3089 |
Number of pages | 11 |
Journal | Blood |
Volume | 80 |
Issue number | 12 |
State | Published - Dec 15 1992 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Immunology
- Hematology
- Cell Biology