title: An increased number of PD-1+ and Tim-3+ CD8+ T cells is involved in immune evasion in gastric cancer.
abstract: OBJECTIVE
  Co-signaling molecules play an important role in T cells. This study was designed to investigate PD-1 and Tim-3 expression on T cells and the relationships between PD-1 and Tim-3 expression and immune evasion in patients with gastric cancer.
  
  
  METHODS
  Using multicolor flow cytometry, we analyzed PD-1 and Tim-3 expression on CD8+ T cells obtained from peripheral blood mononuclear cells (PBMCs) and gastric cancer tissue.
  
  
  RESULTS
  Significantly more PD-1+ and Tim-3+ CD8+ T cells in peripheral blood were found in gastric cancer patients than in healthy controls. PD-1+ CD8+ T cells were significantly correlated with Tim-3+ CD8+ T cells in peripheral blood from the gastric cancer patients (r = 0.29, p = 0.036). Furthermore, significantly greater numbers of PD-1+ and Tim-3+ CD8+ T cells were seen in the gastric cancer tissue samples than in the PBMCs. CD8+ T cells positive for both PD-1 and Tim-3 produced significantly less IFN-gamma than cells negative for both and cells positive for PD-1 and negative for Tim-3.
  
  
  CONCLUSIONS
  An increased number of PD-1+ and Tim-3+ CD8+ T cells is closely related to impaired function of CD8+ T cells in gastric cancer patients.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Tottori University School of Medicine, 36-1 Nishi-cho, Yonago, 683-8504, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Takano
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Tottori University School of Medicine, 36-1 Nishi-cho, Yonago, 683-8504, Japan. sai10@med.tottori-u.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Saito
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Tottori University School of Medicine, 36-1 Nishi-cho, Yonago, 683-8504, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Ikeguchi
mesh_terms: D000368:Aged; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D002478:Cells, Cultured; D005260:Female; D000072597:Hepatitis A Virus Cellular Receptor 2 / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor / Q000276:immunology* / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000276:immunology* / Q000473:pathology*
chemical_list: C448908:HAVCR2 protein, human; D000072597:Hepatitis A Virus Cellular Receptor 2; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D007371:Interferon-gamma
keywords: Gastric cancer; PD-1; T cell; Tim-3