Title: Production of anti-idiotype antibodies for deoxynivalenol and their evaluation with three immunoassay platforms Author
Submitted to: Mycotoxin Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 17, 2014
Publication Date: N/A
Interpretive Summary: Deoxynivalenol (DON) is a toxin produced by certain species of fungi that can infest wheat, barley, and corn worldwide. Because of this the U.S. conducts extensive monitoring of commodities. As part of efforts to improve monitoring of the toxin, kits for detecting DON based upon specific antibodies (immunoassays) have been widely developed. In such kits, the toxin is generally included as a standard against which test samples are compared. This means that the toxin is shipped with the test kits, and that analysts have the potential to be exposed to the toxin when the kits are used. However, materials other than the toxin can potentially be used, provided they mimic the toxin in the assay. Scientists with the Bacterial Foodborne Pathogens and Mycology research unit in Peoria, IL, developed a material (an anti-idiotype antibody) that mimics the effects of the toxin in assays and evaluated the material in three immunoassay formats. This material has the potential to replace the toxin in diagnostic test kits, which would make the kits safer to use and to ship.
Technical Abstract: Immunoassays for deoxynivalenol (DON) that involve the competition for binding to DON-specific antibodies have been widely developed. In such assays, the responses of samples are generally compared to calibration curves generated by using DON in competition with labeled reagents such as enzymatic or fluorescent conjugates of the toxin. However, materials that mimic the toxin can also be used, provided that they compete effectively with the labeled reagents for the DON-specific antibodies. Examples include certain types of anti-idiotype antibodies, obtained by the immunization of animals with toxin-specific antibodies. In the present work, anti-idiotype antibodies were developed which mimicked DON in the ability to bind to a DON-specific monoclonal antibody (Mab). Fab fragments of the Mab (Ab1) were used to immunize rabbits. Sera were screened by competitive direct enzyme linked immunosorbent assay (CD-ELISA) for the presence of anti-idiotype antibodies (Ab2). In order to determine the most effective screening format and also the potential efficacy in various forms of biosensors, the sera were further evaluated in biolayer interferometry (BLI) and fluorescence polarization immunoassay (FPIA) formats. All three formats were used to demonstrate the presence of anti-idiotypes capable of binding to the paratope of the DON antibody (subtypes Ab2ß or Ab2'). Such materials have the potential to replace DON as calibrants in immunoassays for this toxin.