Effects of antifungal agents on the production of cytokines from macrophages stimulated by Aspergillus fumigatu s conidia

Background

We evaluated the immunomodulatory effect of three antifungal agents, amphotericin B (AmB), micafungin (MF) and itraconazole (ITZ), in the aspect of cytokine production and expression of NF-κB in Aspergillus fumigatus conidia-treated RAW264.7 cells, a murine alveolar macrophage cell line.

Materials and methods

We evaluated the cytotoxic effect of antifungal agents using a commercial cell proliferation assay. TNFα and IL-10 production according to stimulation (control, A. fumigatus conidia only, conidia + antifungal drug, conidia + antifungals + GM-CSF) was evaluated and each compared using a commercial ELISA method. NF-κB activation was evaluated by western blot analysis.

Results

AmB, MF and ITZ showed a dose-dependent cytotoxic effect on the tested cells. Stimulation of cells by A. fumigatus conidia induced TNFα production. Pretreatment of AmB at concentrations not affecting cellular survival did not change the production of TNFα compared with conidia-treated cells, but pretreatment of MF or ITZ showed a reduced amount of TNFα production compared with conidia-treated cells. AmB also showed a synergistic effect on TNFα production when simultaneously treated with GM-CSF. IL-10 production was markedly increased when the cells were treated with AmB with conidia. MF and ITZ induced a smaller increase of IL-10 production. AmB also showed a synergistic effect on the production of IL-10 when treated with GM-CSF simultaneously. A. fumigatus conidia enhanced expression of NF-κB. The degree of NF-κB expression was associated with the amount of TNFα and IL-10 produced.

Conclusion

The antifungal agents we used in this experiment showed decreased TNFα production and increased IL-10 production from the RAW264.7 cells stimulated by A. fumigatus conidia after pretreatment of antifungal agents. But more studies such as the association between the immunomodulatory effect and antifungal activity and the difference of the signal pathway of cellular activation according to drugs should be performed.