Radiation-induced cytokine release from human bone marrow

Irradiation (RT) of bone marrow hemopoietfc oeUs and strorna Induces release of growth factors. Transforming growth factor (TGF), platelet derived growth factor (PDGF), and tumor necrosis factor (TNF) are thought to play a rote in radiation-Induced changes In marrow. Their pattern of release after marrow RT was examined. Light density marrow ceHs from normal donors were Irradiated at 0 Gy, 10 Gy, 20 Gy, and 30 Gy. Supernatant were harvested at 1,7,14,21, and at 33 days of culture, at which time an adherent layer had formed. The supematants were assayed by ELISA for TGF-G (Isoform 2), PDGF A/B, and TNF-a Cells were also assayed for counts, viability, and granulocyte/macrophage colony forming units (CFU-GM). Levels of PDGF-A/B and TNF-o, but not of TGF-B2 progressively Increased by day 14 and then declined. Cell counts In the RT flasks decreased after day 14 to numbers lower than controls. Patterns of GM-CSF, SCF, and IL-1a and IL-18 were not significantly different in Irradiated flasks vs. controls. These results suggest that RT induces human marrow hemopotetic and stromaf cells to release PDGF-A/B and TNFa, a production which persists for several days. This pattern of cytoUne stimulation may have Implications for the observed character of radiation-Induced marrow damage.