title: [Construction of genetically modified dendritic cell vaccine expressing bcr/abl fusion gene and inducing specific cytotoxic T lymphocytes to kill K562 cells in vitro].
abstract: OBJECTIVE
  Specific immunological effect mediated by T lymphocytes plays an important role in treating chronic myelocytic leukemia (CML). Dendritic cells (DCs)-based immunotherapy has become popular in treating tumors. This study was to construct DC vaccines by transducing with replication-defective recombinant adenoviruses expressing bcr/abl fusion gene of CML, observe the lethal effects of specific cytotoxic T lymphocytes (CTLs) triggered by genetically modified DC vaccines expressing bcr/abl fusion gene against K562 cells in vitro.
  
  
  METHODS
  DNA fragment of bcr/abl fusion gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) to construct a recombinant adenovirus vector and produce recombinant adenoviruses. DCs were induced from peripheral blood monocytes in vitro, and transfected with recombinant adenoviruses or pulsed with peptide to induce specific CTLs. The lethal effect of CTLs against leukemic K562 cells in vitro was observed.
  
  
  RESULTS
  We successfully constructed the replication-defective recombinant adenoviral vector expressing bcr/abl fusion gene. The recombinant adenoviruses we produced had a high virus titer of 2.0 x 10(10) pfu/mL. Transfection efficiency of DCs in vitro was 50%-60%. DC vaccines expressing bcr/abl fusion gene were successfully prepared and used to induce specific CTLs. With effector:target cell ratios of 40:1 and 20:1, the killing rates of K562 cells by CTLs were (47.6+/-4.7)% and (47.5+/-1.6)% in genetically modified DCs group, (25.8+/-4.4)% and (24.6+/-6.3)% in peptide-pulsed DCs group, and were (5.7+/-1.3)% and (4.5+/-1.6)% in control DCs group. The differences between every two groups were significant (all P<0.05).
  
  
  CONCLUSIONS
  Genetically modified DC vaccine expressing bcr/abl fusion gene has a stronger contribution than peptide-pulsed DCs in triggering specific CTLs against K562 cells.
authors.affiliation: Department of Hematology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 510630, P.R. China.
authors.forename: Wen-Wen
authors.initials: WW
authors.lastname: Wang
authors.forename: Ren-Wei
authors.initials: RW
authors.lastname: Huang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Hu
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Li
authors.forename: Dong-Ning
authors.initials: DN
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: He
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Liu
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D019496:Cancer Vaccines / Q000276:immunology*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D016044:Fusion Proteins, bcr-abl / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016313:Genes, abl; D006801:Humans; D020014:K562 Cells; D010957:Plasmids; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology*; D014162:Transfection
chemical_list: D019496:Cancer Vaccines; D016044:Fusion Proteins, bcr-abl