title: Enhanced T cell immunity by B7-H4 downregulation in nonsmall-cell lung cancer cell lines.
abstract: OBJECTIVE
  T cell immunity plays a critical role in host immune surveillance of tumour cell growth and metastatic spread. This study used small hairpin (sh)RNA-mediated gene silencing to target VTCN1 (B7-H4) expression in a nonsmall-cell lung cancer (NSCLC) cell line (A549)  and evaluated the effects on T cell immune activity using an in vitro coculture system.
  
  
  METHODS
  VTCN1-specific shRNA-expressing plasmid was transfected into A549 cells. Mock transfected and empty plasmid-transfected A549 cells served as controls. VTCN1 expression in A549  cells was determined by reverse transcription-polymerase chain reaction (RT-PCR) for VTCN1 mRNA and Western blotting for B7-H4 protein. Transfected A549 cells were cocultured with Jurkat cells. Jurkat cells were examined for proliferation, apoptosis, cell cycle distribution and  intracellular cytokine mRNA and protein levels.
  
  
  RESULTS
  VTCN1-specific shRNA efficiently knocked down VTCN1 mRNA and B7-H4 protein levels in A549 cells. This downregulation led to enhanced Jurkat cell proliferation, decreased apoptosis, stimulated cell cycle progression and elevated  production of interferon-γ, interleukin (IL)-10 and IL-2.
  
  
  CONCLUSIONS
  B7-H4 negatively regulates T cell-mediated antitumour immunity in NSCLC.
authors.affiliation: Department of Respiratory Medicine, Zhongda Hospital, Southeast University, Nanjing, China.
authors.forename: S-Q
authors.initials: SQ
authors.lastname: Sun
authors.forename: C-G
authors.initials: CG
authors.lastname: Jiang
authors.forename: Y
authors.initials: Y
authors.lastname: Lin
authors.forename: Y-L
authors.initials: YL
authors.lastname: Jin
authors.forename: P-L
authors.initials: PL
authors.lastname: Huang
mesh_terms: D017209:Apoptosis; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018920:Coculture Techniques; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D019169:Jurkat Cells; D008175:Lung Neoplasms / Q000235:genetics / Q000276:immunology / Q000473:pathology; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D060907:V-Set Domain-Containing T-Cell Activation Inhibitor 1 / Q000235:genetics* / Q000378:metabolism*
chemical_list: D016207:Cytokines; D007376:Interleukin-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D060907:V-Set Domain-Containing T-Cell Activation Inhibitor 1; C475826:VTCN1 protein, human; D016753:Interleukin-10; D007371:Interferon-gamma