title: Cholangiocarcinoma-derived exosomes inhibit the antitumor activity of cytokine-induced killer cells by down-regulating the secretion of tumor necrosis factor-α and perforin.
abstract: OBJECTIVE
  The aim of our study is to observe the impact of cholangiocarcinoma-derived exosomes on the antitumor activities of cytokine-induced killer (CIK) cells and then demonstrate the appropriate mechanism.
  
  
  METHODS
  Tumor-derived exosomes (TEXs), which are derived from RBE cells (human cholangiocarcinoma line), were collected by ultracentrifugation. CIK cells induced from peripheral blood were stimulated by TEXs. Fluorescence-activated cell sorting (FACS) was performed to determine the phenotypes of TEX-CIK and N-CIK (normal CIK) cells. The concentrations of tumor necrosis factor-α (TNF-α) and perforin in the culture medium supernatant were examined by using an enzyme-linked immunosorbent assay (ELISA) kit. A CCK-8 kit was used to evaluate the cytotoxic activity of the CIK cells to the RBE cell line.
  
  
  RESULTS
  The concentrations of TNF-α and perforin of the group TEX-CIK were 138.61 pg/ml and 2.41 ng/ml, respectively, lower than those of the group N-CIK 194.08 pg/ml (P<0.01) and 3.39 ng/ml (P<0.05). The killing rate of the group TEX-CIK was 33.35%, lower than that of the group N-CIK (47.35% (P<0.01)). The population of CD3(+), CD8(+), NK (CD56(+)), and CD3(+)CD56(+) cells decreased in the TEX-CIK group ((63.2±6.8)%, (2.5±1.0)%, (0.53±0.49)%, (0.45±0.42)%) compared with the N-CIK group ((90.3±7.3)%, (65.7±3.3)%, (4.2±1.2)%, (15.2±2.7)%), P<0.01.
  
  
  CONCLUSIONS
  Our results suggest that RBE cells-derived exosomes inhibit the antitumor activity of CIK cells by down-regulating the population of CD3(+), CD8(+), NK (CD56(+)), and CD3(+)CD56(+) cells and the secretion of TNF-α and perforin. TEX may play an important role in cholangiocarcinoma immune escape.
authors.affiliation: Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China.
authors.forename: Jiong-Huang
authors.initials: JH
authors.lastname: Chen
authors.affiliation: Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China.
authors.forename: Jian-Yang
authors.initials: JY
authors.lastname: Xiang
authors.affiliation: Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China.
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Ding
authors.affiliation: Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Cao
mesh_terms: D001650:Bile Duct Neoplasms / Q000276:immunology*; D045744:Cell Line, Tumor; D018281:Cholangiocarcinoma / Q000276:immunology*; D055612:Cytokine-Induced Killer Cells / Q000276:immunology*; D015536:Down-Regulation; D055354:Exosomes / Q000502:physiology*; D006801:Humans; D016130:Immunophenotyping; D054353:Perforin / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
chemical_list: D014409:Tumor Necrosis Factor-alpha; D054353:Perforin
keywords: Cholangiocarcinoma; Cytokine-induced killer cells; Immune escape; Tumor-derived exosomes