Effects of mycotoxins on cytokine production and proliferation in EL-4 thymoma cells.
The thymoma cell line EL4.IL-2 (EL-4) was used as a T-cell model to assess the immunotoxic effects of several mycotoxins produced by the Aspergillus-Penicillium and the Fusarium groups. EL-4 cells were stimulated with phorbol 12-myristate 12-acetate (PMA) in the presence of mycotoxins at various concentrations for 5 d and culture supernatants were analyzed for interleukins (IL) IL-2 and IL-5 by enzyme-linked immunosorbent assay (ELISA). The cytokine effects were further related to proliferation and cell viability using the MTT [3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide] assay with absorbance at 570 nm (A570) as the endpoint indicator. IL-2 and IL-5 levels were dramatically increased by cyclopiazonic acid at 50-1000 ng/ml, whereas IL-2 was significantly decreased at 10 microgram/ml. Proliferation was slightly increased at 100-1000 ng/ml cyclopiazonic acid but markedly depressed at 5 and 10 microgram/ml. When EL-4 cells were exposed to 5 and 10 microgram/ml of ochratoxin A, IL-2 production was markedly increased while IL-5 production was significantly decreased. The A570 was significantly decreased by ochratoxin A at 10 microgram/ml. IL-2 and Il-5 production was almost totally suppressed by patulin at concentrations > or = 500 ng/ml and by T-2 toxin at > or = 5 ng/ml. These effects occurred concurrently with marked depression of A570 in the MTT assay. Although A570 was unaffected by either zearalenone or alpha-zearalenol exposure, both IL-2 and IL-5 levels were significantly elevated by these toxins at 5 or 10 microgram/ml. IL-2 and IL-5 production were not affected in EL-4 cells cultured with either the Aspergillus-Penicillium toxins aflatoxin B1 and secalonic acid or the Fusarium toxins wortmannin, fumonisin B1, or fusaric acid at concentrations up to 10 microgram/ml. In total, the EL-4 culture studies indicated that cyclopiazonic acid, ochratoxin A, zearalenone, and alpha-zearalenol could stimulate cytokine production whereas patulin and T-2 toxin were inhibitory. Cytokine dysregulation was not always related directly to perturbations in proliferation. The results suggest that the EL-4 thymoma cell line could be a simple and effective in vitro model for evaluating immunotoxicity of various classes of environmental chemicals.
Marin
M L
ML
Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824-1224, USA.
Murtha
J
J
Dong
W
W
Pestka
J J
JJ
D000730:Androstadienes / Q000633:toxicity; D000818:Animals; D001230:Aspergillus / Q000378:metabolism; D002273:Carcinogens / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D037341:Fumonisins; D005669:Fusaric Acid / Q000633:toxicity; D005670:Fusarium / Q000378:metabolism; D007211:Indoles / Q000633:toxicity; D007376:Interleukin-2 / Q000096:biosynthesis*; D015848:Interleukin-5 / Q000096:biosynthesis*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D009183:Mycotoxins / Q000633:toxicity*; D009793:Ochratoxins / Q000633:toxicity; D010365:Patulin / Q000633:toxicity; D010407:Penicillium / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity; D013945:Thymoma / Q000276:immunology* / Q000473:pathology; D013953:Thymus Neoplasms / Q000276:immunology* / Q000473:pathology; D014407:Tumor Cells, Cultured; D000077191:Wortmannin; D015025:Zearalenone / Q000633:toxicity; D015029:Zeranol / Q000031:analogs & derivatives / Q000633:toxicity
D000730:Androstadienes; D002273:Carcinogens; D037341:Fumonisins; D007211:Indoles; D007376:Interleukin-2; D015848:Interleukin-5; D009183:Mycotoxins; D009793:Ochratoxins; C029659:zearalenol; C025589:ochratoxin A; C056933:fumonisin B1; D015025:Zearalenone; D015029:Zeranol; D010365:Patulin; D005669:Fusaric Acid; D013755:Tetradecanoylphorbol Acetate; C000543:cyclopiazonic acid; D000077191:Wortmannin