BLOOD MONOCYTES MAINTAIN STEM CELL PLASTICITY AFTER REPEATED GROWTH FACTOR CHALLENGE

• Published in: The FASEB journal 2006-03, Vol.20 (5), p.A1106-A1107
• Main Authors: Bluth, Martin H, Meeus, Sarah, Chapman, Michael, Pierre, Joelle, Mueller, Cathy M, Stanek, Albert, Zenilman, Michael E
• Format: Article
• Language: English
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.20.5.A1106-d

Background Non‐embryonic stem cells continue to be of interest in providing an alternate source of pluripotent progenitor cells. However, little is known regarding the resiliency, longevity and the ability to continuously revert to stem cell phenotype of select non‐embryonic stem cell populations. We investigated the ability of blood monocyte‐derived stem cells to maintain their plasticity in culture at differing dosing regimens, culture intervals and repeated growth factor challenge. Methods Blood monocytes were isolated by density centrifugation (Ficoll) with subsequent positive selection (confirmed by flow cytometry, CD14+). Cells were reverted to fibroblastic‐like macrophage (f‐macs) stem cells after culture with growth factors, M‐CSF and LIF. F‐macs were cultured in the absence of growth factors with addition of growth factors after starvation intervals, and morphology, viability, and the ability to maintain or revert to f‐mac status was determined. Cultures were performed in triplicate by independent investigators. Data are expressed as proportion of cells demonstrating changes (+/− SD). Results Addition of growth factors effectively induced monocytes to become f‐macs within 5 days in culture (>80%). Subsequent growth factor starvation of f‐macs induced reversion to monocyte‐like phenotypic changes (83 + 9%). Cells which were starved for 7, 14 and 21 days with subsequent addition of growth factors reverted to f‐mac status (83 + 11%, 75+ 15%, 78+ 15%, respectively). Viability was >92% at all time points in all conditions. Conclusions Blood monocyte derived stem cells demonstrate the ability to revert to f‐mac status despite prolonged starvation conditions. Further investigation of these robust cells may provide another mode of obtaining and propagating stem cells for future therapy.