Abstract: Objective To explore how to improve the mature dendritic cells,we compared the differences between cytokines in promoting the maturation of dendritic cells.We next evaluated the efficacies of several cell penetrating peptides in order to find a high performance CPP with tumor antigens,in order to improve the effectiveness of DC targeted therapy.Methods Several cytokines in different working concentration were in vitro co-cultured with monocytes to induce maturation of dendritic cell.Number and phenotype of the mature dendritic cell were assessed with phase contrast microscope.Surface markers including CD80,CD83,CD86,and HLA-DR were evaluated with flow cytometry.Immunofluorescent staining was used to evaluate the penetrating efficacies of the four peptides TAT,SecPen,PanPro,and Pan.Results GM-CSF in 2 folds concentration didn′t results in increased number of mature dendritic cell when compared with that in conventional concentration(P＞0.05).No statistical significances were found in the expression level of CD80,CD83,CD86,and HLA-DR between the two working concentrations.Compared with conventional method using IL-4,GM-CSF and IFN-γ,number but not functional markers of mature DC was significantly higher when cultured with optimal method(P＜0.05).In comparation with the other three CPPs,SecPen(83.3±3.0%)possess the highest efficacy of internalizing effect(P＜0.05).Conclusion Different concentration of GM-CSF can not increase the number and proportion of mature DC.Compared to the traditional methods,the optimized method is superior in inducing DC maturation than the conventional method.Cell penetrating peptides can efficiently enter DC.However,their penetrating capacity varies significantly.Care must be taken to select the feasible CPP for application in DC vaccines.

Key words: Dendritic cell DC, GM-CSF, Cytokine, CPP