Evaluation of antibovine IgG subclass specific antisera from guinea pigs and goats

A technique for producing specific antibovine IgG2 antibodies is described. The method relies on the abrogation of the class-specific antibody response of guinea pigs to bovine IgG1 by intravenous injection of goat serum immediately before immunisation in the foot pads with bovine IgG2 in adjuvant. Of the 10 resulting antisera, six were judged monospecific for IgG2 by immunoelectrophoresis but, of these, two antisera gave a very faint line in gel diffusion using IgG1 as the antigen. Radial immunodiffusion studies indicated that the strength of the antisera, using IgG2 as the antigen, was similar to antisera of guinea pigs not injected with goat serum before absorption with bovine IgG1. For guinea pigs injected with goat serum, using bovine IgG1 as an immunogen did not result in the production of subclass specific antisera, rather, the specificities were similar to those of animals not receiving goat serum. This data is compared to absorption studies of goat antibovine IgG1 and IgG2 antisera. The relationships of goat and bovine IgG subclasses are discussed.