ISOLATION, PURIFICATION, AND PARTIAL CHARACTERIZATION OF AN AUTOCRINEPERIODONTAL-LIGAMENT CELL CHEMOTACTIC FACTOR

Periodontal ligament (PDL) cells are believed to play a critically imp ortant role in the regeneration of the periodontium. We have suggested that polypeptide growth factors can enhance periodontal regeneration by stimulating PDL cell chemotaxis and mitogenesis. This manuscript de scribes the identification of a novel chemotactic factor isolated from human PDL cells which we named PDL-CTX. PDL-CTX induces the directed migration of human PDL cells in vitro and was found to be a more poten t chemotactic agent than other known growth factors. Additionally, PDL -CTX has no chemotactic effect on gingival fibroblasts or gingival epi thelial cells. Both tryptic digestion and boiling abolished PDL-CTX's biological activity. The designed purification method included Mono-S cation exchange, heparin-sepharose affinity, and microbore reverse-pha se HPLC. The purified factor has a relative molecular weight of approx imately 7000 daltons based on sodium dodecyl sulfate (SDS) gel analysi s. The amino acid composition and partial amino acid sequence were det ermined from HPLC-purified material. These were determined to be uniqu e. Further investigation of the biological functions of PDL-CTX on PDL cells and other ligament cells should help improve our understanding of Ligament repair.