roridin-a and deoxynivalenol

The macrocyclic trichothecenes are a group of potent protein synthesis inhibitors that have been encountered in indoor air and food as a result of infestation by the fungus Stachybotrys. To evaluate the capacity of these mycotoxins to alter immune functions, the effects of satratoxin G, H, F, roridin A, and verrucarin A on interleukin 2 (IL-2) production and viability were evaluated in a murine T-cell model. EL-4 thymoma cells were stimulated with phorbol 12-myristate 13-acetate and ionomycin and concurrently exposed to various concentrations of the trichothecenes. Enzyme-linked immunosorbent assay (ELISA) of supernatants revealed that IL-2 concentrations at 24 and 72 h were significantly increased in cultures that were incubated in the presence of 0.5 to 1 ng/ml of satratoxin H, 1 to 5 ng/ml of isosatratoxin F, 0.1 to 0.5 ng/ml of roridin A, and 0.25 to 0.5 ng/ml of verrucarin A. However, IL-2 levels at these time points were significantly depressed when incubated in the presence of higher concentrations of satratoxin G (> or =2.5 ng/ml), satratoxin H and isosatratoxin F (> or =5 ng/ml), and roridin A and verrucarin A (> or =1 ng/ml). Cell viability, as measured by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, was depressed by each of the trichothecenes in a concentration-dependent manner. MTT responses were significantly decreased by as little as 0.5 ng/ml satratoxin G, roridin A, and verrucarin A and by 2.5 ng/ml of isosatratoxin F and satratoxin H. When these data were compared to those found in EL-4 cells for the 8-ketotrichothecene vomitoxin (deoxynivalenol), a common food contaminant, the macrocyclic trichothecenes were at least 100 times more potent. The results indicate that, at low concentrations, macrocyclic trichothecenes as a group could superinduce IL-2 production even while partially decreasing cell viability, whereas higher concentrations suppressed cytokine production and were markedly cytotoxic. The capacity of these compounds to dysregulate cytokine production in a biphasic fashion may play an etiologic role in outbreaks of human illnesses associated with indoor Stachybotrys contamination.

Topics: Air Microbiology; Air Pollution, Indoor; Animals; Cell Line; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Food Microbiology; Humans; Immunosuppressive Agents; Interleukin-2; Mice; Protein Synthesis Inhibitors; Stachybotrys; T-Lymphocytes, Helper-Inducer; Trichothecenes

A capillary supercritical fluid chromatography/mass spectrometry interface incorporating a heated frit restrictor is described. The trichothecene mycotoxins T-2 toxin, deoxynivalenol and roridin A were used to evaluate the effect of restrictor temperature and carbon dioxide mobile phase on the negative ion chemical ionization (CI) spectra of these compounds under electron capture, proton abstraction and chloride attachment conditions. Restrictor temperatures less than 100 degrees C above the melting point of the samples retarded sample transfer into the mass spectrometer, but neither restrictor temperature nor carbon dioxide mobile phase significantly affected negative ion CI conditions.

Topics: Anti-Bacterial Agents; Gas Chromatography-Mass Spectrometry; Mycotoxins; Sesquiterpenes; Trichothecenes