Enhance efficiency of adenovirus on AAV transfering human RPE cells / 中华实验眼科杂志

ABSTRACT

Background Adeno-associated virus-based vector is one of most efficient vehicles.It presents with a long-term and efficient transfer and expression of therapeutic genes with minimal toxicity.But its delayed-and low-efficient transgene expression limits the application of AAV vector.To explore an improving method of AAV infecting RPE cells is the hot spot. Objeetive Present study was to investigate whether adeno-associated virus (AAV)combined with low dose non-replieable adenovirus(Ad-null)can enhance its infection efficieney on RPE ceils in vitro. Methods Human RPE cells were isolated from the donate eyeballs under the approval of the Ethic Committee of this hospital.The cells were cultured in DMEM containing 10%fetal bovine serum.AAV particles with enhanced green fluorescence protein(EGFP)were added into the medium alone or in combination with different amount of adenovirus for 30 days.The cells were detected under the fluorescence microscope,and the protein expression levels of report gene EGFP in RPE cells were analyzed with Western blotting assay. Results Melanin granules could be found in cultured RPE cells.EGFP was expressed in RPE cells at 2 days after AAV-EGFP infection and peaked at 12 days and remained for about 3-week duration,showing the green influorescence under the influorescence mwroscope.After the cells were infected by AAV2-EGFP with 0.01 to 1000 MOI Ad-null respectively,the number of cells with green influorescence was obviously increased with the enhanced infiuorescence intensity.The enhance of the infection efficiency began in the 0.1 MOI Ad-null group and peaked in 10 MOI Ad-null group.Dead cells were exhibited in the 100 or more MOI Ad-nulor group.Western blotting assay demonstrated that the protein expression level of EGFP in RPE cells enhanced significantly in 1 and 10 MOI Ad-null groups compared with only AAV infection group. Conclusion These finding suggested that the infection efficiency of AAV can be improved significantly when it is used with low dose Ad-null in vitro.This offers a basis for further study of gene therapy.