Relationship between macrophage oxidative metabolism and antitularemia activity influenced by inflammatory agents.

Abstract

A comparative study on the effects of inflammatory agents on oxidative metabolism as it relates to bactericidal function of murine peritoneal macrophages was conducted. Four groups of mice were used for the study. Three groups were injected with different inflammatory agents, peptone (PEP), thioglycollate (TG), and glycogen (GLY), 72 h prior to harvesting of macrophage., from the perito~eal cavity. The fourth group served as the control group and provided resident macrophages. Macrophages were examined for in vitro intracellular killing of Francisella tularensis, phagocytic index, oxidative metabolism, and nitroblue tetra" zolium (NBT) reduction. A relationship between oxidative metabolism and degree of resistance by macrophages was exhibited. PEP-elicited macrophages had the greatest increase in resistance to F. tularensis, greatest increase in superoxide production, and the most macrophages able to reduce NBT when compared to resident macrophages. TG-elicited macrophages had a significant increase in the susceptibility to F. tularemis, smallest increase in superoxide production and the fewest macrophages able to reduce NBT when compared to resident macrophages. GLY-elicited macrophages did not have a significant difference in the intracellular killing of F. tularensis from resident macrophages. Elicited macrophages had a significant increase in the uptake of F. tularensis when compared to the resident macrophages. Preliminary evidence indicates that F. tularensis is able to circumvent oxidative metabolism of murine macrophages.