Production of chemotactic factor for lymphocyte by digestion of IgG with a highly purified polymorphonuclear leukocyte neutral thiol proteinase.

In the present study, we purified a neutral thiol proteinase from dog PMN leukocytes and indicated that the proteinase elaborated the chemotactic factor for lymphocytes by cleavage of IgG. The neutral thiol proteinase was purified about 744-fold by ion-exchange chromatographies and affinity chromatography, and the final preparation was over 70% pure. After incubation of dog IgG with the proteinase, three distinct protein peaks were seen by the gel filtration on Sephadex G-200. Only the third peak, perhaps a dialyzable peptide, showed a significant chemotactic activity for dog lymphocytes.