Expression of cytokine mRNA during immuno-modulation of murine suppressor macrophages

In order to analyze the mechanism of immuno-modulation by LPS on murine peritoneal suppressor macrophages, we have, using RNase protection assay, checked the changes of mRNA expression pattern of several cytokine genes during the immuno-modulation. It has been found that, after treating peritoneal suppressor macrophages with LPS, mRNAs of IL-12 p35, IL-12 p40, IL-6 and IFN-gamma are newly appeared, while those of IL-1 alpha, IL-1 beta and IL-1Ra are increased and those of other cytokines, like TGF-beta 1 and MIF are not changed at all. It seems certain that those cytokines, whose expression is increased by LPS stimulation, may be responsible for the functional changes of suppressor macrophages during immuno-modulation. Among these changes, the appearance of IL-12 mRNA may play a critical role, and, in this regard, the synergetic effect between IFN-gamma and LPS on the increase of IL-12 p35 and Il-12 p40 mRNA expression is an interesting finding.