Targetting the production of monoclonal antibodies to the hemagglutinating adhesin of Bacteroides (Porphyromonas) gingivalis by injection of an immunoprecipitate from crossed immunoelectrophoresis.

This study has demonstrated that the production of monoclonal antibodies (MAbs) can be targetted to a predetermined antigen by immunization with the relevant immunoprecipitate (IP) excised from an agarose gel. The target antigen was the hemagglutinating adhesin HA-Ag2 of Bacteroides (Porphyromonas) gingivalis precipitated from a crude antigen extract with a rabbit antiserum in crossed immunoelectrophoresis. The immunization protocol used included: subcutaneous injection of 1 IP in Freund's complete adjuvant to Balb/c mice on day 0 and of 0.5 IP on day 8, followed by an intravenous booster injection of outer membranes on day 15, 4 days before the fusion. Of the 9 MAbs obtained, 8 were specific for HA-Ag2 since they reacted with its characteristic electrophoretic bands at 43 and 49 kDa. The ninth MAb was specific for the B. gingivalis lipopolysaccharide. The method allows for easy obtention of MAbs of predetermined specificity without purification of the antigen.