Chitinase 3-like-1 enhances bacterial adhesion to colonic epithelial cells through the interaction with bacterial chitin-binding protein

Abstract

Dysregulated host/microbial interactions play a pivotal role in the pathogenesis of inflammatory bowel disease. We previously reported that chitinase 3-like-1 (CHI3L1) enhances bacterial adhesion and invasion on/into colonic epithelial cells (CECs). In this study, we designed to identify the exact mechanism of how CHI3L1 enhances the bacterial adhesion on CECs in vitro. As compared with wild type (WT) of Serratia marcescens, chitin binding protein (CBP) 21 knockout strain of S. marcescens significantly decreased the adhesion to SW480 cells that express CHI3L1 endogenously. A CBP21 fusion protein was produced with CBP21-expressing vector, which was transformed into BL21 strain of Escherichia coli. CBP21 overexpression significantly increased the adhesion, but not invasion, of nonpathogenic E. coli. The adhesion of S. marcescens and CBP21-overexpressing E. coli was inhibited by coculture with chitin, but not with other carbohydrates. After overexpressing CHI3L1 on SW480 cells, the adhesion rate of CBP21-overexpressing E. coli was further increased by approximately twofold. Genetically engineered E. coli with a single mutation of either Thy-54 or Glu-55 position of CBP21 exhibited a decreased binding ability, and the binding was 74% diminished by the combined mutations of three amino acids (Thy-54, Glu-55 and Glu-60) as compared with WT. Inhibition of CHI3L1 by anti-CHI3L1 antibody or CHI3L1-specific short interfering RNA reduced the adhesion of CBP21-overexpressing E. coli to CECs. In conclusion, CHI3L1 is involved in the enhancement of CBP-expressing bacterial adhesion to CECs. CBP21 and its homologs may be required for the CHI3L1-mediated enhancement of bacterial adhesion to CECs through the conserved amino-acid residues.

EepR Mediates Secreted-Protein Production, Desiccation Survival, and Proliferation in a Corneal Infection Model

“…Consistent with this idea, chiA mutants of other species of Enterobacteriaceae are less able to attach to epithelial cells in vitro (52). The N terminus of GbpA from Vibrio cholerae shares ϳ50% amino acid sequence identity with Cbp21 of S. marcescens; mutation of the genes for these polysaccharide binding proteins conferred a reduction in attachment to epithelial cells in vitro (54,55). Therefore, it is possible that the chitinases and chitin binding proteins controlled by EepR contribute to pathogenesis under certain circumstances.…”

Serum YKL-40 in Risk Assessment for Colorectal Cancer: A Prospective Study of 4,496 Subjects at Risk of Colorectal Cancer

“…The expression of YKL-40 is highly induced in colonic epithelial cells and macrophages in areas with intestinal inflammation and enhances potentially pathogenic, but not nonpathogenic, bacterial adhesion, and invasion into colonic epithelial cells (17,18). It has been suggested that growth-stimulating effects of epithelial YKL-40 in response to inflammatory or stressful stimuli are a critical and physiologic function in remodeling and maintaining the basic architecture of intestinal epithelium (25). Furthermore, the chitin-binding motif of YKL-40 is specifically associated with activation of Akt signaling in colonic epithelial cells, enhances the secretion of the proinflammatory cytokines IL8, and TNFa, and promotes proliferation of colonic epithelial cells (19).…”

Surface Layers of Clostridium difficile Endospores

“…Peroxiredoxin 1 (a 2-Cys-peroxiredoxin), secreted from tumor cells (22), was shown previously to induce proinflammatory cytokines in macrophages via interactions with Toll-like receptor 4 and to promote chronic inflammation, which could support tumor growth (28). Regarding chitinases, it is now clear that some inflammatory conditions of the gastrointestinal (GI) tract (inflammatory bowel disease [IBD] and ulcerative colitis [UC]) lead to the induction of host cell chitinases by triggering the increased uptake of intracellular bacteria by colonic cells (16,17) and in potentiating the development of epithelial tumorigenesis (8). Considering that some symptoms of CDAD resemble those of both IBD and UC, C. difficile chitinase may play a direct role in infection and not simply in macromolecular degradation.…”