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Lipopolysaccharide activates innate immune responses in murine intestinal myofibroblasts
Author(s) -
Walton Kristen LW,
Collins Leisha,
Sartor R Balfour
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1465-c
Subject(s) - lipopolysaccharide , proinflammatory cytokine , secretion , innate immune system , mapk/erk pathway , chemistry , immune system , signal transduction , microbiology and biotechnology , biology , inflammation , immunology , biochemistry
Background Myofibroblasts (MF) play an important role in wound healing in the intestine. A compromised epithelial barrier exposes intestinal subepithelial MF to luminal bacterial products. However, the responses of murine intestinal MF to bacterial adjuvants are not well defined. We investigated the reponsiveness of primary murine MF to lipopolysaccharide (LPS). Methods Primary murine MF lines were established from 129 SvEv mouse ileum or colon by collagenase digestion and mechanical disruption. Expression of toll‐like receptors (TLR) ‐2, ‐4, ‐5, and ‐9 were detected by RT‐PCR. Intracellular responses to 20 ng/ml LPS were assessed by western blotting for phosphorylated NFκB, IκBα, ERK1/2, and cyclooxygenase‐2 (COX‐2). Secretion of prostaglandin E2 (PGE2), IL‐6, IL‐10, and the neutrophil chemoattractant KC/CXCL1 after stimulation with E. coli LPS or E. coli lysate was measured by ELISA. Results All cell lines tested expressed TLR‐2, TLR‐4, TLR‐5, and TLR‐9 mRNA. LPS caused rapid phosphorylation of NFκB p65 and degradation of IκBα. Phosphorylation of ERK 1/2 was detected between 15 – 120 minutes of LPS stimulation. COX‐2 protein was increased in MF after 24 hr of LPS treatment. LPS and E. coli lysate induced secretion of PGE2, IL‐6, and KC, but not IL‐10. Conclusions Primary murine intestinal MF respond to LPS, evidenced by activation of the NFκB and MAPK signaling pathways and induced secretion of the proinflammatory molecules KC, IL‐6, and PGE2. These data support the hypothesis that MF may regulate adjacent epithelial and immune cell responses to luminal bacterial adjuvants. Supported by NIH.