The effects of
deoxynivalenol (DON or
vomitoxin) and four closely related 8-ketotrichothecenes on proinflammatory
cytokine and
chemokine production were evaluated in a clonal human macrophage model. U-937 cells, which represent a human monocytelike histocytic
lymphoma, were differentiated into macrophages by preincubation with
phorbol 12-myristate 13-acetate (PMA). Differentiated macrophages were incubated with DON in the absence or presence of
lipopolysaccharide (LPS), and supernatant was analyzed by
enzyme-linked
immunosorbent assay (ELISA) for the proinflammatory
cytokines interleukin-6 (IL-6) and
tumor necrosis factor-alpha (
TNF-alpha), and for the
chemokine interleukin-8 (IL-8). In the absence of LPS, DON at 500 or 1,000 ng/ml upregulated
TNF-alpha production as early as 3 h and up to 6 h, whereas 100 to 1,000 ng/ml of DON significantly increased production of
IL-6 from 3 to 24 h and
IL-8 from 6 to 48 h. In cells costimulated with 0.2 microg/ml LPS, DON at 500 or 1000 ng/ml markedly superinduced
TNF-alpha and
IL-8 production. Although 100 ng/ml of DON also potentiated LPS-induced
IL-6 production, 500 or 1,000 ng/ ml of the toxin suppressed the LPS-induced
IL-6 response. Four other 8-ketotrichothecenes,
fusarenon X,
nivalenol, 3-acetyl DON, and 15-acetyl DON, were also capable of upregulating or suppressing
TNF-alpha,
IL-6, and
IL-8 production at concentrations similar to that of DON. In total, the results suggest that DON and other 8-ketotrichothecenes have the potential to both directly induce and superinduce proinflammatory
cytokine and
chemokine expression in human macrophages, even at toxin concentrations that are cytotoxic.