Chitinase 3-like-1 enhances bacterial adhesion to colonic epithelial cells through the interaction with bacterial chitin-binding protein
Chitinase 3-like-1 enhances bacterial adhesion to colonic epithelial cells through the interaction with bacterial chitin-binding protein
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DOI：
10.1038/labinvest.2008.47
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发表时间：
2008-08-01
影响因子：
5
通讯作者：
Mizoguchi, Emiko
中科院分区：
文献类型：
--
作者：
Kawada, Mayumi;Chen, Chun-Chuan;Mizoguchi, Emiko
失调的宿主/微生物相互作用在炎症性肠病的发病机制中起关键作用。我们以前报道过几丁质酶3-like-1（CHI 3L 1）可增强细菌在结肠上皮细胞（CEC）上的粘附和侵袭。本研究旨在探讨CHI 3L 1在体外增强细菌对CEC粘附的确切机制。与野生型粘质沙雷氏菌（WT）相比，几丁质结合蛋白（CBP）21基因敲除的粘质沙雷氏菌（S. marcescens显著降低对内源性表达CHI 3L 1的SW 480细胞的粘附。将重组表达载体转化大肠杆菌BL 21，获得重组蛋白。CBP 21过表达显著增加非致病性大肠杆菌的粘附，但不增加侵袭。杆菌S. marcescens和过量表达CBP 21的E.与甲壳素共培养对大肠杆菌的生长有抑制作用，而与其他碳水化合物共培养则无抑制作用。在SW 480细胞上过表达CHI 3L 1后，过表达CBP 21的E.大肠杆菌的感染进一步增加了约两倍。基因工程E.与野生型相比，突变后的CBP 21结合力下降74%，突变后的CBP 21结合力下降74%。通过CHI 3L 1抗体或CHI 3L 1特异性短干扰RNA抑制CHI 3L 1，可降低CBP 21过表达的E. coli转化为CEC。总之，CHI 3L 1参与增强表达CBP的细菌对CEC的粘附。CBP 21及其同源物可能是CHI 3L 1介导的通过保守氨基酸残基增强细菌粘附于CEC所必需的。
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.