Objective:To study the antitumor effect and mechanism of cocultured CIK cells modified with IL-24 gene and autologous DCs on HL-60 cells in vitro.Methods:DCs and CIK cells were prepared routinely from human peripheral blood mononuclear cells ( PBMC).IL-24 gene was transferred into CIK cells via electroporation.The cells obtained were named CIK-IL24.RT-PCR and ELISA were used to evaluate expression of IL-24 gene in transfected CIK cells.The phenotypic changes of CIK cells were identified by flowcytometry analysis.The concentration of IFN-γ and TNF-α in supernatant of CIK was determined by ELISA.FCM was used to determine the cytotoxicity of cocultured CIK cells modified with IL-24 gene and autologous DCs against HL-60 cells.Results:Eukaryotic expressing plasmid pcDNA3.0-IL24 was transferred into CIK cells successfully via electroporation.The expressing rate of CD3~+、CD3~+CD56~+ cells had no significant change in CIK cells.However,the rate of CD4~+CD25~+ cells was significantly decreased compared with that of the control group.Expression of adhesion molecules CD54,CXCR4 were significantly increased on CD3+CD56+ cells.CIK-IL24 cells produced markedly higher levels of IFN-γ and TNF-α as compared with the CIK cells.By comparison with non-transfected CIK cells co-cultured with DCs,transfected CIK cells co-cultured with DCs had a significantly higher lytic activity against HL-60 cells.Conclusion:IL-24 gene modification can enhance the anti-tumoral immunity of CIK cells,the mechanism of which might be related to the increased secretion of IFN-γ,TNF-α,up-regulation of adhesion molecule expression,and reduction of the rate of CD4~+CD25~+ cells in CIK cells.

Objective To study the antitumor effect and mechanism of co-cultured cytokine-induced killer(CIK) cells and autologous DC modified with IL-24 gene on A549 cells in vitro. Methods DC and CIK cells were prepared routinely from human peripheral blood mononuclear cells(PBMC). Recombinant adenovirus vector pAdEasy-1-pTrack-CMV-IL-24 was extracted from DH5α, it was lineared with Pac I and transfected into A293 cells, and then the IL-24 recombined adenovirus(Ad-IL-24) was obtained. Ad-IL-24 was used to infect DC. The cells obtained were named DC-IL-24. RT-PCR and ELISA were used to evaluate the expression of IL-24 gene in transfected DC. The phenotypes change of DC were identified by flow cytometry analysis, the concen-tration of IL-12 and TNF-α in supernatant of DC were determined by EIJSA. The ability of CIK producing per-forin was measured by homolysis method. FCM was used to determine the cytotoxicity of cocultured CIK cells and autologous DC modified with IL-24 gene to A549 cells. Results We obtained the high titre of Ad-IL-24.IL-24 gene was transfered into DC successfully via Ad-IL-24. The green fluorescence was observed on DC by fluorescence microscope. The expression rate of CD80, CD83, HI.A-DR, CD40, CXCR4 on DC-IL-24 was sig-nificantly increased compared with that of the control group. DC-IL-24 produced markedly higher levels of IL-12 and TNF-α as compared with DC. DC-IL-24 can enhance the ability of CIK cells producing perforin. On com-parison with non-transfected DC co-cultured with CIK cells, transfected DC co-cultured with CIK cells had a sig-nificantly higher lytic activity against A549 cells. Conclusion IL-24 gene modification can enhance the anti-tu-moral immunity of DC. The mechanism of which might be related to the increased secretion of IL-12 and TNF-α, up-regulation expression of co-stimulatory molecules and MHC Ⅱ class molecules on DC, promoting the acti-vation and maturation of DC, and then enhancing CIK cells to generate specific anti-tumoral immunity.