Regulation of cytokine-induced neutrophil chemoattractant in rat bone marrow-derived macrophages by inflammatory mediators

During the course of inflammation, macrophages are highly influenced by their local environment and changes in the cytokine milieu. Exposure of macrophages to various factors during different phases of the inflammatory response may have a strong influence on the pattern of gene expression, which a macrophage exhibits. We examined how these mediators affect the regulation of the expression and production of cytokine-induced neutrophil chemoattractant (CINC). Our study demonstrates that CINC can be induced in bone marrow-derived macrophages by lipopolysaccharide, interleukin-lp, tumor necrosis factor-alpha (TNF alpha), and interferon-gamma/TNF alpha. These mediators are factors which a macrophage would be expected to encounter early in an inflammatory process. In contrast, transforming growth factor-beta (TGF beta), which is expressed late in the inflammatory process during mesenchymal cell proliferation and tissue repair, did not induce detectable amounts of CINC and functioned to suppress CINC production stimulated by early inflammatory mediators. Suppression of CINC production occurred whether TGF beta was added simultaneously, 12 or 24 h prior to the stimulus.