Inhibition of the multiplication of Listeria monocytogenes in a murine hepatocyte cell line (ATCC TIB73) by IFN-gamma and TNF-alpha.

The effects of IFN-gamma and TNF-alpha on intracellular multiplication of Listeria monocytogenes in a murine enbryonic hepatocyte cell line (ATCC TIB 73) were investigated. Neither IFN-gamma nor TNF-alpha alone (10, 25, or 100 ng/ml) significantly inhibited intracellular multiplication of L. monocytogenes. In contrast, addition of both IFN-gamma and TNF-alpha (10, 25, or 100 ng/ml) significantly inhibited intracellular listerial multiplication. The anti-listerial effects of IFN-gamma and TNF-alpha were not blocked by adding aminoguanidine or catalase. Nor did IFN-gamma and TNF-alpha treated hepatocyte monolayers produce detectable amounts of nitric oxide or hydrogen peroxide. These findings suggest that the effects of IFN-gamma and TNF-alpha may be independent of reactive oxygen (ROI) and nitrogen (RNI) intermediates.