Production of polyclonal antibodies to the trichothecene mycotoxin 4,15-diacetylnivalenol with the carrier-adjuvant cholera toxin

Abstract

The trichothecene mycotoxin 4,15-diacetylnivalenol (DNIV) was conjugated to cholera toxin (DNIV-CT) for use as an immunogen and as an adjuvant for specific antibody production. Repeated intravenous injection of 7.5 micrograms of the conjugate was effective at generating specific antibodies to DNIV in rabbits as determined by enzyme-linked immunosorbent assay (ELISA). When small amounts (1 to 10 micrograms per animal) of DNIV-CT were used to immunize mice, polyclonal antibodies were observed as early as 4 weeks of immunization. The relative affinity of the antibodies to DNIV increased with the immunogen dose in mice. Antibodies were not detectable in either rabbits or mice that were injected with DNIV conjugated to the carrier protein bovine serum albumin or when DNIV-CT was blocked with glutaraldehyde. Competitive ELISA of mouse and rabbit serum revealed that the antibodies were most specific for DNIV but reacted to a small extent with fusarenone-X, deoxynivalenol, and nivalenol. No reactivity was observed with 3- or 15-acetyldeoxynivalenol. The results suggest that specific polyclonal antibodies can be prepared against a trichothecene when CT is used as an adjuvant and carrier protein. DNIV antibodies will be useful for monitoring the compound in food in conjunction with other trichothecene antibodies, detection of DNIV-producing cultures, and investigation of 8-ketotrichothecene biosynthesis.