The role of superoxide anion and lysosomal enzymes in anti-listerial activity of elicited peritoneal macrophages

Abstract

The in vitro effect of superoxide anion and lysosomal enzyme activity on the killing of Listeria monocytogenes EGD (listeria) by peritoneal macrophages (PM) was investigated. Generation of superoxide anion by PM stimulated with phorbol myristate acetate (PMA) was significantly increased by intraperitoneal injection of Lactobacillus casei YIT 9018 (LC9018) or Corynebacterium parvum (CP), but not by injection of peptone. However, superoxide anion generation by LC9018-elicited PM stimulated with listeria was not increased any more than that by peptone-elicited PM, and generation of superoxide anion by the PM was affected by the difference in stimuli. The killing of listeria by LC9018- or CP-elicited PM in vitro was significantly less than that by peptone-elicited PM or resident PM. Significant correlation was observed between the anti-listerial activity of PM and the intracellular killing of listeria by PM. On the other hand, beta-glucuronidase and beta-N-acetyl-D-glucosaminidase activities of LC9018-elicited, CP-elicited, or resident PM were significantly weaker than those of peptone-elicited PM, and no significant correlation was observed between the increase in beta-glucuronidase and beta-N-acetyl-D-glucosaminidase activities and the increase in anti-listerial activity. These results suggest that increase in the activity of lysosomal enzymes such as beta-glucuronidase and beta-N-acetyl-D-glucosaminidase is not correlated with the anti-listerial activity of PM, and that superoxide anion has very little effect on the anti-listerial activity of PM in vitro.