Lipopolysaccharide binding protein and serum amyloid a secretion by human intestinal epithelial cells during the acute phase response

The acute phase proteins LPS binding protein (LBP) and serum amyloid A (SAA ) are produced by the liver and are present in the circulation, Roth protei ns have been shown to participate in the immune response to endotoxins, The intestinal mucosa forms a large surface that is continuously exposed to th ese microbial products, By secret-ion of antimicrobial and immunomodulating agents, the intestinal epithelium contributes to the defense against Bacte ria and their products, The aim of this study was to explore the influence of the inflammatory mediators TNF-alpha, IL-6, and IL-1 beta on the release of LBP and SAA by intestinal epithelial cells (IEC), In addition, the indu ction of LBP and SAA release by cell lines of intestinal epithelial cells a nd hepatic cells was compared, The data obtained show that in addition to l iver cells, IEC also expressed LBP mRNA and released bioactive LBP and SAA upon stimulation, Regulation of LBP and SAA release by IEC and hepatocytes was typical for class 1 acute phase proteins, although differences in regul ation between the cell types were observed. Endotoxin did not induce LBP an d SAA release, Glucocorticoids mere demonstrated to strongly enhance the cy tokine-induced release of LBP and SAA by IEC, corresponding to hepatocytes, The data horn this study, which imply that human IEC can produce LBP and S AA, suggest a role for these proteins in the local defense mechanism of the gut to endotoxin. Furthermore, the results demonstrate that tissues other than the liver are involved in the acute phase response.