Bleomycin and FK 565 enhance the release of GM-CSF from LPS-stimulated BALB/c peritoneal macrophages.

The anti-tumour antibiotic Bleomycin, the experimental immunostimulatory tripeptide FK 565, and the immunosuppressive agent Cyclosporin A were examined for their in vitro effects on the release of the haemopoietic cytokine Granulocyte Macrophage Colony-Stimulating Factor (GM-CSF) from LPS stimulated BALB/c adherent peritoneal macrophages. FK 565 and Bleomycin produced an increase in GM-CSF release indicating that these agents are capable of stimulating peritoneal macrophage populations. Cyclosporin A was found to have no effect.