Protective effect of granulocyte-colony stimulating factor against amphotericin B-induced myelosuppression in vitro.

Amphotericin B causes suppression of bone marrow (BM) progenitor cells in vitro. Granulocyte colony stimulating factor (G-CSF) enhances the proliferation of myeloid cells. The present study defines the role of G-CSF in preventing amphotericin B-induced myelosuppression. G-CSF increased the proliferative potential of BM and protected against amphotericin B-induced myelosuppression if it was added to the medium during the early phase of exposure of BM to amphotericin B. Monoclonal antibodies to tumour necrosis factor-alpha (TNF) or interferon-gamma (IFN) inhibited the myelosuppression partially; simultaneous presence of both these antibodies completely abrogated this suppression, suggesting that both TNF alpha and IFN gamma were involved in amphotericin-induced myelosuppression. TNF- or IFN-induced suppression of BM was also inhibited by G-CSF. These data suggest that G-CSF prevents the amphotericin B-induced myelosuppression by antagonizing the suppressive effects of TNF and IFN and by enhancing the proliferative activity of BM.