TY - JOUR

T1 - Differential effect of immune cells on non-pathogenic Gram-negative bacteria-induced nuclear factor-κB activation and pro-inflammatory gene expression in intestinal epithelial cells

AU - Haller, Dirk

AU - Holt, L

AU - Parlesak, Alexandr

AU - Zanga, J

AU - Bäuerlein, A

AU - Sartor, R B

AU - Jobin, C

N1 - (Ekstern)

PY - 2004

Y1 - 2004

N2 - We have previously shown that non-pathogenic Gram negative bacteria induce RelA phosphorylation, nuclear factor (NF)-κB transcriptional activity and pro-inflammatory gene expression in intestinal epithelial cells (IEC) in vivo and in vitro. In this study, we investigated the molecular mechanism of immune-epithelial cell cross-talk on Gram-negative enteric bacteria-induced NF-κB signalling and pro-inflammatory gene expression in IEC using HT-29/ MTX as well as CaCO-2 transwell cultures Interestingly, while differentiated HT-29/MTX cells are unresponsive to non-pathogenic Gram negative bacterial stimulation, interleukin-8 (IL-8) mRNA accumulation is strongly induced in Escherichia coli- but not Bacteroides vulgato-stimulated IEC cocultured with peripheral blood (PBMC) and lamina propria mononuclear cells (LPMC). The presence of PBMC triggered both E. coli- and B. vulgatus-inAuceA mRNA expression of the Toll-like receptor-4 accessory protein MD-2 as well as endogenous IκBα phosphorylation, demonstrating similar capabilities of these bacteria to induce proximal NF-κB signalling. However, B. vulgatus failed to trigger IκBa degradation and NF-κB transcriptional activity in the presence of PBMC. Interestingly, B. vulgatus- and E. coli-derived lipopolysaccharide-induced similar IL-8 mRNA expression in epithelial cells after basolateral stimulation of HT-29/PBMC cocultures. Although luminal enteric bacteria have adjuvant and antigenic properties in chronic intestinal inflammation, PBMC from patients with active ulcerative colitis and Crohn's disease differentially trigger epithelial cell activation in response to E. coli and E. coli-derived LPS. In conclusion, this study provides evidence for a differential regulation of non-pathogenic Gram-negative bacteria-induced NF-κB signalling and IL-8 gene expression in IEC cocultured with immune cells and suggests the presence of mechanisms that assure hypo-responsiveness of the intestinal epithelium to certain commensally enteric bacteria.

AB - We have previously shown that non-pathogenic Gram negative bacteria induce RelA phosphorylation, nuclear factor (NF)-κB transcriptional activity and pro-inflammatory gene expression in intestinal epithelial cells (IEC) in vivo and in vitro. In this study, we investigated the molecular mechanism of immune-epithelial cell cross-talk on Gram-negative enteric bacteria-induced NF-κB signalling and pro-inflammatory gene expression in IEC using HT-29/ MTX as well as CaCO-2 transwell cultures Interestingly, while differentiated HT-29/MTX cells are unresponsive to non-pathogenic Gram negative bacterial stimulation, interleukin-8 (IL-8) mRNA accumulation is strongly induced in Escherichia coli- but not Bacteroides vulgato-stimulated IEC cocultured with peripheral blood (PBMC) and lamina propria mononuclear cells (LPMC). The presence of PBMC triggered both E. coli- and B. vulgatus-inAuceA mRNA expression of the Toll-like receptor-4 accessory protein MD-2 as well as endogenous IκBα phosphorylation, demonstrating similar capabilities of these bacteria to induce proximal NF-κB signalling. However, B. vulgatus failed to trigger IκBa degradation and NF-κB transcriptional activity in the presence of PBMC. Interestingly, B. vulgatus- and E. coli-derived lipopolysaccharide-induced similar IL-8 mRNA expression in epithelial cells after basolateral stimulation of HT-29/PBMC cocultures. Although luminal enteric bacteria have adjuvant and antigenic properties in chronic intestinal inflammation, PBMC from patients with active ulcerative colitis and Crohn's disease differentially trigger epithelial cell activation in response to E. coli and E. coli-derived LPS. In conclusion, this study provides evidence for a differential regulation of non-pathogenic Gram-negative bacteria-induced NF-κB signalling and IL-8 gene expression in IEC cocultured with immune cells and suggests the presence of mechanisms that assure hypo-responsiveness of the intestinal epithelium to certain commensally enteric bacteria.

KW - Gene expression

KW - Gram negative bacteria

KW - Inflammatory bowel disease: intestinal epithelial cells

KW - NF-κB

KW - Signalling

U2 - 10.1111/j.1365-2567.2004.01874.x

DO - 10.1111/j.1365-2567.2004.01874.x

M3 - Journal article

C2 - 15147574

AN - SCOPUS:2542583822

VL - 112

SP - 310

EP - 320

JO - Immunology

JF - Immunology

SN - 0019-2805

IS - 2

ER -