TLR4 signaling in cancer cells promotes chemoattraction of immature dendritic cells via autocrine CCL20.
Toll-like receptors (TLRs) are involved in the production of inflammatory mediators upon specific ligands stimuli. Chemokines are important inflammatory mediators capable of chemoattracting diverse immune cells. In addition to normal immune cells, the expression of TLRs and chemokines has been detected in various tumor cells. However, the roles of TLRs and chemokines expressed by tumor cells in the processes of tumor progression and immune escape have not been fully elucidated. Here we report that TLR4 ligation by lipopolysaccharide (LPS) significantly promotes CT-26 colon cancer cells to produce chemokine CCL20 via activation of TLR4 signaling pathways. We find that LPS treatment of CT-26 cells can significantly increase the chemoattraction of immature dendritic cells (DC) by the autocrine CCL20. Our studies suggest that TLR4 expressed by tumor cells may be involved in the induction of chemokines like CCL20, providing a potential linkage between chronic inflammation and tumor immune escape.
Wang
Li
L
Institute of Immunology, Zhejiang University School of Medicine, 388 Yuhangtang Road, Hangzhou, 310058, PR China; Institute of Immunology and National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai 200433, PR China.
Liu
Qiuyan
Q
Sun
Qiaoling
Q
Zhang
Chaoxiong
C
Chen
Taoyong
T
Cao
Xuetao
X
D000818:Animals; D019898:Autocrine Communication / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology*; D045744:Cell Line, Tumor; D054418:Chemokine CCL20 / Q000276:immunology*; D002630:Chemotactic Factors / Q000276:immunology*; D003110:Colonic Neoplasms / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D051379:Mice; D051197:Toll-Like Receptor 4 / Q000276:immunology*
C493447:CCL20 protein, mouse; D054418:Chemokine CCL20; D002630:Chemotactic Factors; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4