Interleukin-6 production in human intestinal epithelial cells increases in association with the heat shock response

Background. In recent studies, IL-1β stimulated the production of IL-6 in human enterocytes. The heat shock response influences the production of inflammatory mediators in certain cell types. We tested the hypothesis that heat shock regulates IL-1β-induced IL6 production in human intestinal epithelial cells. Materials and methods. Cultured Caco-2 cells, a human intestinal epithelial cell line, were exposed to thermal heat shock at 43°C for 1 h and recovered at 37°C for 1 h. Cells were harvested for analysis of heat shock protein-70 (HSP-70) production by Western blotting. In other experiments, IL-1β (0.5 ng/ml) was added following heat shock and recovery. IL-6 protein was measured in culture medium after 24 h by enzyme-linked immunosorbent assay and IL-6 messenger RNA (mRNA) levels were measured after 4 h by competitive reverse transcriptase polymerase chain reaction. Results. Heat shock resulted in the production of HSP-70 and potentiated IL-1β- induced IL-6 production. The response to heat shock was associated with increased IL-6 mRNA levels. Conclusions. The results suggest that IL-1β- induced IL-6 production in human enterocytes is increased in association with the heat shock response. The biological role of heat shock-potentiated IL-6 production in the enterocyte remains to be determined.