Production and characterization of monoclonal antibodies against major allergens of American cockroach.

From several fusion experiments between spleen cells obtained from BALB/c mice immunized with partially purified Cr-PI of American cockroach and NS-1 cells, growth was observed in many wells. Seven stable subclones secreting monoclonal antibodies (mAbs) against Cr-PI, as determined by enzyme-linked immunosorbent assay (ELISA) with high absorbance values and immunoblot analysis, were obtained. All seven mAbs were characterized as IgG1 subclass by immunodiffusion, and reacted strongly with 72 kilodaltons (kD) of Cr-PI which have been identified as a major allergen of American cockroach. Six mAbs were found to have similar epitope specificities against Cr-PI by ELISA. The remaining mAb was found to have different epitope specificities with others. Interestingly, all mAbs did not react with any components of crude extracts of Oriental and German cockroaches as determined by immunoblot analysis and ELISA. A mAb-based double-antibody sandwich ELISA was developed, and the ELISA was dose-dependent and capable of detecting as little as 140 ng of Cr-PI allergen.