Cellular effects of human leukocyte hydrolases. I. Human gingival fibroblasts.

Experiments were carried out to determine whether lysosomal enzymes had the ability to adversely affect the viability of human gingival fibroblasts. These studies were accomplished in vitro using lysosomal enzymes derived from human polymorphonuclear leukocytes. The results strongly indicated that under the conditions of these experiments, lysosomal enzymes were incapable of mediating cell destruction. In fact, the only measurable effect was to release the cells from their growth surface in a manner similar to other known proteases. Even this capability was not expressed in the presence of naturally occurring inhibitors which are widely distributed in many body fluids, such as serum and inflammatory exudates. These results suggest that PMN leukocyte granule enzymes may not contribute significantly as mediators of the cellular destruction observed in inflammatory diseases in general, and inflammatory periodontal disease in particular.