Enhancing effect of IL-24 gene modified dendritic cells co-cultured with CIK cells on cytotoxicity against A549 cells / 中华微生物学和免疫学杂志

ABSTRACT

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.