Anti-idiotypic antibody as potential serodiagnostic reagent for detection of bluetongue virus infection.

Polyclonal anti-idiotypic antibodies (anti-Ids) were generated by the sequential immunization of rabbits with three mouse monoclonal antibodies (MAb1s) specific for a major bluetongue virus (BTV) protein, VP7. The anti-Ids, designated RAb2s, recognized idiotopes which were located within or near the antigen-combining sites of the MAb1s and were associated with both heavy and light chains of MAb1s. RAb2s inhibited the MAb1s from binding to BTV antigens, and their interaction with MAb1s was inhibited by BTV antigens. By recognizing the common idiotopes, RAb2s detected anti-BTV antibodies from bovine antisera; their interaction was also partially inhibited by BTV antigens. These results indicated that RAb2s recognized the common idiotopes on anti-VP7 antibodies obtained from mice and cattle and that at least a portion of RAb2s were internal-image anti-Ids that functionally mimicked VP7. RAb2s may be used to substitute for the tissue culture-derived viral antigen in currently used serological assays for the detection of antibodies to BTV.