Macrophage tumour cell lines (PU5-1.8, P388D1) produced detectable granulocyte macrophage colony-stimulating (CSF-2) activity measured using a factor-dependent cell line FDC-P1. The production of CSF-2 was enhanced by endotoxin and inhibited by serum, and correlated inversely with [3H]TdR incorporation. mRNA isolated from PU5-1.8 or P388D1 cells initiated CSF-2 production when injected into Xenopus laevis oocytes. The specific activity in this assay was unaltered in mRNA isolated from endotoxin-treated cells. The results suggest that endotoxin acts at a post-transcriptional level.
- Cell Division/drug effects
- Cell Line
- Colony-Stimulating Factors/biosynthesis
- Leukemia P388/metabolism
- Leukemia, Experimental/metabolism
- Leukemia, Myeloid/metabolism
- Xenopus laevis