title: Cell origins and significance of IL-17 in malignant pleural effusion.
abstract: OBJECTIVE
  T cells are dominant in the immune regulation of malignant pleural effusion (MPE). However, it is unclear about the role of IL-17+ T cells, particularly for IL-17+CD8+ Tc17 cells in antitumor immunity. This retrospective study is aimed at evaluating the prognostic significance of IL-17+ T cells in patients with MPE.
  
  
  METHODS
  The frequency of IL-17+CD4+ Th17 and IL-17+CD8+ Tc17 cells in peripheral blood (PB), pleural fluids (PF), and tumor tissues in 24 patients undergoing thoracoscopy was determined by flow cytometry, immunohistochemistry, and ELISA. The association among the different measures was analyzed by Spearman's correlation tests.
  
  
  RESULTS
  The percentages of PF Th17 and Tc17 cells were significantly higher than those in the PB of MPE patients and healthy controls (p < 0.01). Analysis of Th17 and Tc17 cells in the tumor tissues indicated that the percentages of Th17 and Tc17 cells in the invading tumor edge were significantly higher than those in the non-tumor tissues and intra-tumor regions (p < 0.05). More importantly, the percentages of IL-17+ T cells were associated with prolonged survival of patients with MPE.
  
  
  CONCLUSIONS
  Both Th17 and Tc17 cells were involved in the tumor immunity against MPE. Increased frequency of Tc17 cells may serve as a biomarker for the prognosis of patients with MPE.
authors.affiliation: Department of Respiratory Medicine, The First College of Clinical Medical Science, Yichang Central People's Hospital, China Three Gorges University, Yi Ling Road 183#, Yi Chang, 443003, Hubei, People's Republic of China, 236766535@qq.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Gong
authors.forename: S X
authors.initials: SX
authors.lastname: Chen
authors.forename: B A
authors.initials: BA
authors.lastname: Gao
authors.forename: R C
authors.initials: RC
authors.lastname: Yao
authors.forename: L
authors.initials: L
authors.lastname: Guan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D020381:Interleukin-17 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000276:immunology*; D012189:Retrospective Studies; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology*
chemical_list: D020381:Interleukin-17