Protection of Mice against Brucella Abortus by Immunization with Polyclonal Anti-Idiotype Antibodies

Abstract

Polyclonal goat anti-idiotypic antibodies containing internal images which mimic Brucella abortus antigens were generated from rabbit polyclonal idiotypes specific for partially purified extract of B. abortus (PX III). The anti-idiotypic antibodies were purified using two-step immunoaffinity column chromatography. The presence of internal images was demonstrated by competitive inhibition analysis using an enzyme-linked immunosorbent assay. Several groups of BALB/c mice were vaccinated with the anti-idiotypic antibodies. The vaccinated mice showed a high serum titer of antibodies specific for B. abortus. When the vaccinated mice were challenged with a virulent B. abortus strain 2308, > 90 % reduction of bacteria in the spleen as compared to the unvaccinated control groups was seen. Immunoblotting experiments using antiserum from vaccinated mice demonstrate the ability to distinguish vaccinated mice from B: abortus infected mice. Our data indicate that the anti-idiotypic antibody containing internal images of B. abortus may be used as a vaccine and the induced antibody can be distinguished by immunoblotting from antibodies generated by natural infection with B. abortus.