Potential role of chitinases and chitin-binding proteins in host-microbial interactions during the development of intestinal inflammation
Hoa T. Tran1, Nicolas Barnich2,3 and Emiko Mizoguchi1,4
1Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA, 2Universite Clermont 1, Pathogenic Bacterienne Instinale, JE2526, Unite Sous Contrat Institut National de la Recheche Agnomique 2018, Clermont-Ferrand, France, 3Institut Universitaire de Technologie en Genie Biologique, Aubiere, France and 4Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, USA.
Offprint requests to: Emiko Mizoguchi, MD, PhD, Assistant Professor of Medicine, Harvard Medical School, Massachusetts General Hospital, GRJ 825D, 55 Fruit Street, Boston, MA 02114, USA. e-mail: emizoguchi@partners.org
Summary. The small and large intestines contain an abundance of luminal antigens derived from food products and enteric microorganisms. The function of intestinal epithelial cells is tightly regulated by several factors produced by enteric bacteria and the epithelial cells themselves. Epithelial cells actively participate in regulating the homeostasis of intestine, and failure of this function leads to abnormal and host-microbial interactions resulting in the development of intestinal inflammation. Major determinants of host susceptibility against luminal commensal bacteria include genes regulating mucosal immune responses, intestinal barrier function and microbial defense. Of note, it has been postulated that commensal bacterial adhesion and invasion on/into host cells may be strongly involved in the pathogenesis of inflammatory bowel disease (IBD). During the intestinal inflammation, the composition of the commensal flora is altered, with increased population of aggressive and detrimental bacteria and decreased populations of protective bacteria. In fact, some pathogenic bacteria, including Adherent-Invasive Escherichia coli, Listeria monocytogenes and Vibrio cholerae are likely to initiate their adhesion to the host cells by expressing accessory molecules such as chitinases and/or chitin-binding proteins on themselves. In addition, several inducible molecules (e.g., chitinase 3-like 1, CEACAM6) are also induced on the host cells (e.g. epithelial cells, lamina proprial macrophages) under inflammatory conditions, and are actively participated in the host-microbial interactions. In this review, we will summarize and discuss the potential roles of these important molecules during the development of acute and chronic inflammatory conditions. Histol Histopathol 26, 1453-1464 (2011)
Key words: Chitinase, Inflammatory bowel disease, Bacteria, Colonic epithelial cells, CEACAM
DOI: 10.14670/HH-26.1453