Anti‐idiotypic antibody identifies the structural similarity between the phosphatidylcholine‐specific monoclonal antibody and phosphatidylcholine‐specific lipid transfer protein

Abstract

The polyclonal anti‐idiotypic antibody (Anti‐Id) has been raised against a monoclonal antibody (mAb) that specifically binds to phosphatidylcholine (PC). The anti‐Id bound strongly to PC‐specific mAbs, but not to the other mAbs that bind to phosphatidylserine, indicating that the anti‐Id recognizes the cross‐reactive idiotopes expressed on the PC‐specific mAbs. The anti‐Id also showed an extensive cross‐reaction with the PC‐specific lipid transfer protein isolated from bovine liver and inhibited the lipid transfer activity of the protein. These results strongly suggest that the anti‐Id recognizes a common structure shared between PC‐specific mAbs and the PC‐specific lipid transfer protein.