Production of β-defensin-2 by human colonic epithelial cells induced by Salmonella enteritidis flagella filament structural protein

We recently showed that FliC of Salmonella enteritidis increased human beta -defensin-2 (hBD-2) expression, and now describe the signaling responsible pathway. FliC increased the intracellular Ca2+ concentration ([Ca2+](in)) in Caco-2 cells. The [Ca2+](in) increase induced by FliC was prevented by U73122 and heparin, but not by chelating extracellular Ca2+ or pertussis toxin. The FliC-induced increase in hBD-2 promoter activity via nuclear factor kappaB (NF-kappaB) was also inhibited by chelation of intracellular Ca2+ or by U73122. We conclude that FliC increased [Ca2+](in). via inositol 1,4,5-trisphosphate, which was followed by up-regulating hBD-2 mRNA expression via an NF-kappaB-dependent pathway. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.