[Effect of lipopolysaccharide of the pseudotuberculosis bacterium on the functional activity of macrophages]

Study of the effect of lipopolysaccharide (LPS) of Y. pseudotuberculosis on the culture of peritoneal macrophages of guinea pigs has established that in concentrations of 1-10 micrograms/ml LPS stimulated the absorption and digestive activity of the macrophages. In concentrations of 50-100 micrograms/ml it had a cytotoxic effect on the cell elements and inhibited their phagocytic function. The study of the LPS effect on absorption and liberation of 14C-labeled bacteria of Y. pseudotuberculosis showed that the biopolymer increased 2-3 times the uptake of the labeled antigen from the macrophages and lowered its elimination. In the experiments on mice infected with a labeled culture of S. aureus no increase in the uptake under the effect of the pseudotuberculosis LPS was observed, whereas an increase in the rate of the label elimination was stated. The difference was statistically significant. The results of the experiments are indicative of the specific effect of LPS. The study demonstrated a significant role of LPS of Y. pseudotuberculosis in the pathogenesis and protection of the host from this infection.