Clonorchis sinensis excretory/secretory products promote the secretion of TNF-alpha in the mouse intrahepatic biliary epithelial cells via Toll-like receptor 4.
BACKGROUND
Toll-like receptor 4 (TLR4), as one of the most important pathogen pattern recognitions (PPRs) plays a central role in elicitation of innate immunity and mediation of adaptive responses against foreign antigens. However, little is known of the roles of TLR4 in the immune responses of biliary epithelial cells (BECs) induced by Clonorchis sinensis, a parasite of significance in human health.


METHODS
In the present study, the primary mouse intrahepatic biliary epithelial cells (MIBECs) were pre-treated with TLR4 inhibitor peptide or control peptide and then stimulated by excretory/secretory products (ESP) of C. sinensis, respectively. The expressions of TLR4 and relative cytokines were determined using western blot and a bead-based analytic detection system, respectively.


RESULTS
The results showed that ESP of C. sinensis significantly increased the expression of TLR4 which promoted the expression of MyD88 and NF-κB in BECs; the levels of TNF-α but not IL-6 from MIBECs stimulated by ESP alone were also considerably increased, compared with the group of the medium stimulated. However, the concentration of TNF-α was significantly decreased when MIBECs were pre-treated with TLR4 inhibitor. In addition, ESP could depress the level of IL-6 in MIBECs which was elevated by LPS.


CONCLUSIONS
Our data for the first time demonstrate that ESP of C. sinensis can potently induce secretion of pro-inflammatory cytokines via TLR4 in MIBECs, which suggests that TLR4 plays an important role in host defenses against C. sinensis and the pathogenesis of clonorchiasis.
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. yanchao6957@163.com.
Chao
C
Yan
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. 316987724@qq.com.
Yan-Hong
YH
Wang
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. 714693211@qq.com.
Qian
Q
Yu
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. 253392563@qq.com.
Xiao-Dan
XD
Cheng
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. 1097526129@qq.com.
Bei-Bei
BB
Zhang
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. 413923975@qq.com.
Bo
B
Li
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. 1262179198@qq.com.
Bo
B
Zhang
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. Tangrenxian-t@163.com.
Ren-Xian
RX
Tang
Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, Xuzhou 221004, Jiangsu Province, People's Republic of China. ZKY02@163.com.
Kui-Yang
KY
Zheng
D000818:Animals; D001659:Biliary Tract / Q000473:pathology; D015153:Blotting, Western; D002478:Cells, Cultured; D003003:Clonorchiasis / Q000473:pathology; D003004:Clonorchis sinensis / Q000502:physiology*; D004847:Epithelial Cells / Q000276:immunology*; D054884:Host-Pathogen Interactions; D051379:Mice; D008954:Models, Biological; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha