Application of polybrene to increase transfection efficiency of lentiviral vector in bone marrow derived dendritic cells

Objective To investigate the toxicity and optimal concentration of polybrene on lentiviral vector transduction of bone marrow derived dendritic cells (BMDCs). Methods The BMDCs suspensions in mice were prepared and randomly divided into experimental and control groups. The BMDCs in experimental groups were treated with different concentrations of polybrene, and those in control groups were added with phosphate buffer (PBS). Cell counting kit-8 (CCK-8) assay and annexin V-fluoresceine isothiocyanate (FITC)/propidium iodide (PI) staining were performed to detect cells viability and apoptosis. Add to BMDCs suspensions were added with lentiviral vector [multiplicity of infection (MOI)=10] and the mixture was divided into experimental and control groups. The mixture in experimental groups was treated with different concentrations of polybrene, and that in control groups was given PBS. The expression of green fluorescent protein (GFP) was observed by fluorescence microscope every day. After the BMDCs were stimulated to mature, the GFP expression was detected using flow cytometry. The t test was used for comparison between two groups. Results The number of living cells in experimental group was significantly less than in control group when polybrene ≥11 mg/L [The absorbance (A) values were 0.881±0.007 vs. 1.031±0.017, t=7.832, P<0.05]. The GFP expression in experimental groups was significantly higher than in control groups. The highest GFP expression was observed when polybrene at 8 mg/L. Conclusion Polybrane shows dose-dependent toxicity on BMDCs, and in the safe range of concentration, polybrane can significantly increase the transfection efficacy of lentiviral vector to BMDCs and the optimal concentration is 8 mg/L. Key words: Polybrene; Lentiviral vector; Bone marrow derived dendritic cells