Isolation and characterization of recombinant variable domain of heavy chain anti-idiotypic antibodies specific to aflatoxin B1

Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain (VHH). The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F(ab')2 fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic (anti-Id) responses. Antigen-specific elution method was used for panning private anti-Id VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay (ELISA). Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.