Corynebacterium parvum treatment of P388 tumor-bearing mice. I. Lysosomal enzyme levels in adherent peritoneal cells and peritoneal lavage fluid.

BDF1 mice treated with Corynebacterium parvum (C. parvum) 2 days before an implant of 106 P388 leukemic cells had up to an 110% increase in survival time above control; Bacillus Calmette-Guérin (BCG) treatment was ineffective. Acid phosphatase and beta-glucuronidase were measured in adherent peritoneal lavage cells and beta-glucuronidase in peritoneal lavage fluid form mice treated with C. parvum or BCG 2 days before the implant of P388 cells. In the presence of the tumor, adherent peritoneal cells from C. parvum-treated animals had a 250-300% increased specific lysosomal enzyme activity above control values (cells form animals receiving tumor implant alone). Peak enzyme activity which occurred on day 3 was not present in adherent cells from BCG-treated tumor-bearing animals or the control animals. The beta-glucuronidase activity in peritoneal lavage fluid was elevated by the tumor cells, BCG, or C. parvum. Peak levels occurred on day 5 regardless of the treatment with an additive effect present on day 5 in animals receiving the combination of tumor with C. parvum. The evidence indicated the development of a different pattern of enhanced lysosomal enzyme activity if the immunopotentiator protected against the P388 tumor vs one that did not. Protection was associated with an increase in lysosomal enzyme activity in adherent cells with no increase in lavage fluid in the presence of tumor cells. Changes in cellular enzyme activity may prove to be diagnostic for antitumor activity by an immunostimulant.