Enzymatic degradation of tumor cells damaged by antibody plus complement.

Rapid degradation of ascites tumor cells damaged by the action of antibody plus complement was found to be accomplished by all proteolytic enzymes active at physiologic pH that were tested. For three types of murine ascites tumor cells (Ehrlich ascites, sarcoma-180, and L1210 leukemia), this rate of degradation at low trypsin concentrations was proportional to a high power of enzyme concentration. This suggests that the simultaneous action of two or more enzyme molecules at adjacent cell surface sites is necessary. Cell degradation was assayed by determination of cell volume distribution with a Coulter multi-channel particle size analyzer. The present study may offer clues to in vivo mechanisms of cell degradation.