title: Characterization of the modes of action of deoxynivalenol (DON) in the human Jurkat T-cell line.
abstract: Deoxynivalenol (DON) is one of the most abundant mycotoxins worldwide and mostly detected in cereals and grains. As such, DON poses a risk for many adverse health effects to human and animals. In particular, immune cells are very sensitive to DON, with the initiating step leading to toxicity being a binding to the eukaryotic 60S ribosomal subunit and induction of ribotoxic stress. The present study aimed to: (1) extend insight into the mechanism of action (MOA) of DON in immune cells; and (2) understand why immune cells are more sensitive to DON than most other cell types. Previously published microarray studies have described the effects of DON on immune cells. To build upon these findings, here, immunocytological and biochemical studies were performed using human T-lymphocyte Jurkat cells that were exposed for 3 h to 0.5 µM DON. Induction of ER stress by DON was confirmed by immunocytology demonstrating increased protein expression of two major ER stress markers ATF3 and DDIT3. T-cell activation was confirmed by induction of phosphorylation of protein kinases JNK and AKT, activation of NF-κB (p65), and increased expression of NFAT target gene NUR77; each of these are known inducers of the T-cell activation response. Induction of an oxidative stress response was also confirmed by monitoring the nuclear translocation of major oxidative stress markers NRF2 and KEAP1, as well as by changes (i.e. decreases) in cell levels of reduced glutathione. Lastly, this study showed that DON induced cleavage of caspase-3, an event known to mediate apoptosis. Taken together, these results allowed us to formulate a potential mechanism of action of DON in immune cells, i.e. binding to eukaryotic 60S ribosomal subunit → ribotoxic stress → ER stress → calcium release from the ER into cytoplasm → T-cell activation and oxidative stress → apoptosis. It is proposed that immune cells are more sensitive to DON than other cell types due to the induction of a T-cell activation response by increased intracellular calcium levels.
authors.affiliation: RIKILT-Institute of Food Safety, Wageningen University and Research Centre , Wageningen , the Netherlands .
authors.forename: Madhumohan R
authors.initials: MR
authors.lastname: Katika
authors.forename: Peter J M
authors.initials: PJ
authors.lastname: Hendriksen
authors.forename: Henk
authors.initials: H
authors.lastname: van Loveren
authors.forename: Ad
authors.initials: A
authors.lastname: A C M Peijnenburg
mesh_terms: D051700:Activating Transcription Factor 3 / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D002523:Edible Grain / Q000378:metabolism; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D019169:Jurkat Cells; D000072019:Kelch-Like ECH-Associated Protein 1; D008213:Lymphocyte Activation / Q000187:drug effects / Q000235:genetics; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1 / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D054683:Ribosome Subunits, Large, Eukaryotic / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D051742:Transcription Factor CHOP / Q000378:metabolism*; D014255:Trichothecenes / Q000378:metabolism / Q000633:toxicity*
chemical_list: C490449:ATF3 protein, human; D051700:Activating Transcription Factor 3; D015415:Biomarkers; C497249:DDIT3 protein, human; D047908:Intracellular Signaling Peptides and Proteins; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; D016328:NF-kappa B; C495635:NFE2L2 protein, human; C539821:NR4A1 protein, human; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D014255:Trichothecenes; D051742:Transcription Factor CHOP; D053148:Caspase 3; C007262:deoxynivalenol
keywords: Apoptosis; ER stress; Jurkat cells; NF-κB; NFAT; deoxynivalenol; immunotoxicity; oxidative stress