Enhancement of IL-6 receptor β chain (gp130) expression by IL-6, IL-1 and TNF in human epithelial cells

Analysis of the IL-6 Receptor β chain (gp130) mRNA expression on the two human epithelial cell lines UAC and Hep3B reveals that it is enhanced by IL-6, IL-1 and TNF treatment. In the case of UAC cells, TNF action might be mediated by IL-6. For Hep3B cells, TNF seems to exert a direct effect on gp130, as no IL-6 expression is detected after stimulation by this cytokine. On the same cells, increase of the binding of an anti-gp130 monoclonal antibody was observed after treatment by TNF, which denotes the effective appearance of new gp130 molecules on the cell surface. All this cytokines seem to act selectively on the β chain of the IL-6 receptor. This probably reflects the importance for some cells to have gp130 represented on their membrane in inflammatory contexts.