Production of monoclonal antibody against FimA protein from Porphyromonas gingivalis in rice cell suspension culture

Major fimbriae (FimA) of Porphyromonas gingivalis play an important role in the adherence of the bacterium to oral surfaces, making them a target for the development of a vaccine against periodontal disease. In our previous study, monoclonal antibodies to FimA were expressed in tobacco plants using the agroinfiltration method. In this report, for easy purification, monoclonal antibodies to FimA were produced and accumulated in rice callus suspension culture. The accumulated antibodies were purified by protein G-affinity chromatography. The plant-produced monoclonal antibodies inhibited the binding of P. gingivalis to saliva-coated hydroxyapatite beads, as well as the invasion of oral epithelial KB cells due to the bacterium. The antibodies enhanced the intracellular killing of P. gingivalis by polymorphonuclear neutrophils. These results suggest that FimA-specific monoclonal antibodies produced in a rice suspension culture were easily purified and biologically active against P. gingivalis, and thus may be used for passive immunization to prevent P. gingivalis-induced periodontal disease.