Use of monoclonal antibodies to identify thymopoietin in cultured human thymic epithelial cells.

Murine monoclonal antibodies (mAbs) were developed to discriminate thymopoietin, a human thymic hormone, and thysplenin, a closely related molecule found in spleen. Three of these recognized both native and synthetic thymopoietin as well as thysplenin. Together they define two non-overlapping epitopes which withstand sodium dodecyl sulfate denaturation and can be detected by western blotting. We used these three mAbs to demonstrate the production of thymopoietin by cultured thymic epithelial cells for up to several weeks. Three additional mAbs were selective for thysplenin. Highly specific mAbs will be useful for characterizing further these physiologically distinct polypeptides.