Effect of T lymphocytes induced by dendritic cells modified by proliferating cell nuclear antigen- Epitope andinterleukin-18 gene on colonic cancer cells

Abstract

Objective To investigate the apoptosis of colonic cancer cells co-cultured with T lymphocytes induced by dendritic cells modified by proliferating cell nuclear antigen (PCNA)-Epitope and interleukin-18 (IL-18) genes.Methods The experiment was divided into four groups,including DCs group,empty vector group,PCNA-Epitope transfection group,and PCNA-Epitope plus IL-18 gene group. Everygroup was operated according to DCs vs.T ratio (1∶ 10).The empty vector plasmid (pIRES-EGFP),PCNA-Epitope plasmid [ plRES-EGFP-PCNA(6) ] and plasmid loaded with PCNA-Epitope and IL-18 gene [ pIRES-EGFP-PCNA(6)/IL-18 ] were transfected into peripheral blood-derived dendritic cells by non-lipid polymer-based reagent,then co-cultured with T lymphocytes,respectively.The supernatants of immunocytes were cultured with colonic cancer cells according to the ratio of T lymphocytes vs.colonic cancer cells (5∶ 1,10∶1,20∶1,40∶1 ).The apoptosis of colonic cancer cells was examined by using flow cytometry.Results The apoptosis of colonic cancer cells could be induced in every group. The apoptosis in the pIRES-EGFP-PCNA(6)/IL-18 group was significantly higher than in DCs group,empty vector group,and PCNA-Epitope transfection group.The optimal ratio of T lymphocytes vs.colonic cancer cells was 40∶ 1.Conclusion The supernatants of T lymphocytes induced by DCs that were treated with the PCNA-Epitope and IL-18 gene can induce apoptosis of more colonic cancer cells. Key words: Colonic carcinoma; Dendritic cells; Proliferating cell nuclear antigen; Interleukin-18; Apoptosis