Marker of cemento-periodontal ligament junction associated with periodontal regeneration

Objective: The purpose of this study was to identify factors promoting formation of the cemento‐periodontal ligament junction. Background: Regeneration of the cemento‐periodontal ligament junction is an important factor in recovery of the connective tissue attachment to the cementum and it is important to identify all specific substances that promote its formation. To clarify the substances involved in cemento‐periodontal ligament junction formation, we produced a monoclonal antibody (mAb) to human cemento‐periodontal ligament junction (designated as the anti‐TAP mAb) and examined its immunostaining properties and reactive antigen. Methods: Hybridomas producing monoclonal antibody against human cemento‐periodontal ligament junction antigens were established by fusing P3U1 mouse myeloma cells with spleen cells from BALB/c mice immunized with homogenized human cemento‐periodontal ligament junction. The mAb, the anti‐TAP mAb for cemento‐periodontal ligament junction, was then isolated. The immunoglobulin class and light chain of the mAb were examined using an isotyping kit. Before immunostaining, antigen determination using an enzymatic method or heating was conducted. Human teeth, hard tissue‐forming lesions, and animal tissues were immunostained by the anti‐TAP mAb. Results: The anti‐TAP mAb was positive in human cemento‐periodontal ligament junction and predentin but negative in all other human and animal tissues examined. In the cemento‐osseous lesions, the anti‐TAP mAb was positive in the peripheral area of the cementum and cementum‐like hard tissues and not in the bone and bone‐like tissues. The anti‐TAP mAb showed IgM (kappa) and recognized phosphoprotein. Conclusion: The anti‐TAP mAb is potentially useful for developing new agents promoting cementogenesis and periodontal regeneration.