Exacerbation of non‐steroidal anti‐inflammatory drug‐induced enteropathy in C‐C chemokine receptor type 7‐deficient mice

Abstract

Non-steroidal anti-inflammatory drugs (NSAIDs) induce intestinal enteropathy and the pathophysiology is related to immune-mediated mechanisms. We aimed to investigate the role of C-C chemokine receptor type 7 (CCR7) which regulates immune cell migration in NSAID-induced enteropathy. Injury of the small intestine was evaluated 24h after the subcutaneous injection of indomethacin in CCR7-deficient (Ccr7-/- ) and wild-type (WT) mice. The cellular profile and cytokine production in intestinal cells were analyzed. Indomethacin-induced enteropathy was evaluated in mice adoptively transferred with CD103+ dendritic cells (DCs) from Ccr7-/- or WT mice. Indomethacin induced more severe intestinal injury in Ccr7-/- mice than in WT mice. The major inflammatory cytokines were not increased and the proportion of regulatory T cells following indomethacin injection was not decreased in Ccr7-/- mice compared with WT mice. The expression of interleukin (IL)-22 binding protein (IL-22BP), which inhibits IL-22 activity, was significantly higher in CD103+ DCs from Ccr7-/- mice than those from WT mice. Mice adoptively transferred with CD103+ DCs isolated from Ccr7-/- mice exhibited more severe intestinal injury following indomethacin injection compared with those adoptively transferred with CD103+ DCs of WT mice. Ccr7-/- mice injected with indomethacin showed a significant reduction in regenerating islet-derived 1 (Reg1) mRNA expression, which is regulated by IL-22, in intestinal epithelial cells. C-C chemokine receptor type 7 deficiency exacerbated NSAID-induced enteropathy in association with an altered phenotype of CD103+ DCs that produces IL-22BP. CCR7 contributes to protect the small intestine from NSAID-induced mucosal injury.