Fumonisin B1 alters cell cycle progression and interleukin‐2 synthesis in swine peripheral blood mononuclear cells

Fumonisin B 1 (FB 1 ) is a mycotoxin produced by Fusarium verticillioides, a fungus that commonly contaminates maize. In the present study, we investigated the effects of FB 1 on swine peripheral blood mononuclear cells (PBMC) by measuring cell proliferation, cell cycle progression and interleukin (IL)‐2 production. Forty‐eight hours after treatment in vitro , FB 1 induced a decrease of PBMC proliferation as measured by cell counting and dehydrogenase enzyme activity. This effect was observed starting with 10 μM FB 1 . The effect of FB 1 on cell cycle progression was analyzed by flow cytometry. Incubation of PBMC with FB 1 increased the percentage of cells blocked in G0/G1 phase of the cell cycle. Treatment with 200 μM FB 1 induces a high blockade of the cell cycle, with 92.4% of cells in G0/G1 phase. This blockade was observed in all lymphocyte subsets tested (CD2 + , CD4 + , CD8 + and Ig + ) as evidenced by dual staining for DNA and membrane surface molecules. A significant decrease of IL2 production was also observed in the supernatants of ConA stimulated PBMC treated with 100 or 200 μM FB 1 . In conclusion, these data suggest that FB 1 may affect immune functions by inhibiting lymphocyte proliferation and IL2 production, suggesting a possible role of FB 1 exposure during infectious disease and cancer.