PHAGOCYTOSIS OF OPSONIZED YEAST INDUCES TUMOR-NECROSIS-FACTOR-ALPHA MESSENGER-RNA ACCUMULATION AND PROTEIN RELEASE BY HUMAN POLYMORPHONUCLEAR LEUKOCYTES

In this report we show that phagocytosis of yeast particles opsonized with IgG (Y-IgG) by human polymorphonuclear cells (PMN) results in the selective induction of tumor necrosis factor (TNF-alpha) messenger RNA (mRNA) and release of its mature protein. Lipopolysaccharide (LPS) was also found able to induce TNF-alpha secretion by PMN, but was a less potent stimulus compared with Y-IgG. There was no evidence of interleukin-6 (IL-6) gene expression in PMN after phagocytosis of Y-IgG or in response to LPS, whereas IL-6 mRNA expression and secretion were induced by either stimulus in monocytes. These findings demonstrate that a physiological function such as phagocytosis modulates the gene expression for a cytokine in PMN and shed new light on the understanding of the pathogenesis of the inflammatory process.