title: [Soluble PD-1 can augment anti-tumor immunity induced by HSP70-peptide complex in tumor-bearing mice].
abstract: OBJECTIVE
  To explore the effect of soluble PD-1 (sPD-1) on the anti-tumor immunity induced by HSP70-peptide.
  
  
  METHODS
  BALB/c mice were immunized with HSP70-peptide, then the cytotoxic activity of splenocytes was detected by MTT colorimetry. Expression of PD-1 and its ligand on splenocytes was determined by semi-quantitative RT-PCR. For some mice, sPD-1 plasmid was injected alone or in combination with HSP70-peptide and then the tumor weight and cytotoxic activity of splenocytes were measured.
  
  
  RESULTS
  sPD-1 alone had anti-tumor effect. HSP70-peptide complex not only induced tumor-specific cytotoxic T lymphocytes(CTLs), but also promoted expression of PD-1 and its ligand. The combination of sPD-1 with HSP70-peptide complex induced much more stronger anti-tumor effect as compared with sPD-1 or HSP70-peptide alone. sPD-1 transfection in mice could enhance the cytotoxic activity of splenocytes from immunized mice.
  
  
  CONCLUSIONS
  sPD-1 enhanced the anti-tumor efficacy of HSP70-peptide.
authors.affiliation: Department of Biochemistry & Molecular Biology, Tongji Medical College of Huazhong University of Sciences and Technology, Wuhan 430030, China. zhy1024@21cn.com
authors.forename: Xiao-hong
authors.initials: XH
authors.lastname: Wang
authors.forename: Gui-mei
authors.initials: GM
authors.lastname: Zhang
authors.forename: Yu-fei
authors.initials: YF
authors.lastname: He
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Zuo-hua
authors.initials: ZH
authors.lastname: Feng
mesh_terms: D000818:Animals; D015703:Antigens, CD; D000954:Antigens, Surface / Q000378:metabolism / Q000494:pharmacology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology* / Q000494:pharmacology; D006801:Humans; D007114:Immunization; D008024:Ligands; D008113:Liver Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D010446:Peptide Fragments / Q000276:immunology / Q000494:pharmacology; D010957:Plasmids; D061026:Programmed Cell Death 1 Receptor; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection
chemical_list: D015703:Antigens, CD; D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; D018840:HSP70 Heat-Shock Proteins; D008024:Ligands; C105992:PDCD1 protein, human; D010446:Peptide Fragments; D061026:Programmed Cell Death 1 Receptor