Gene transfer characteristics and cell tropism of recombinant adenovirus in the hippocampus of adult mouse / 中华神经医学杂志

ABSTRACT

Objective To explore the gene transfer characteristics and different cell tropism of the recombinant adenovirus serotype 5 (rAd5) driven by murine cytomegalovirus (mCMV) immediate-early promoter in the hippocampus of adult mouse,and provide a basis for adenovirus-mediated transgene research in the hippocampus of mouse in the future.Methods Forty-two male healthy adult C57BL/6 mice were injected with the titre and volume matched rAd5 vectors which contained enhanced green fluorescent protein (EGFP) sequences as a reporter gene.Then animals (n=6 for each point) were killed 1,3,7,14,30,45,60 days after injection.The coronal cryosections of brains were processed,and EGFP expression was observed with fluorescence microscopy.Double-label immunofluorescence method was used to observe the EGFP expression in different types of cells to identify the cell tropism in the hippocampus.Results The expression of EGFP carried by rAd5 vectors was detected on the first day after the transfection,with peak expression between days 3 and 45,while EGFP activity decreased sharply 60 days after transfection.EGFP highly expressed in the dentate subgranular zone (SGZ) of the hippocampus but rarely in the granule cell layer (GCL) of the dentate gyrus.Moreover,no EGFP was detected in the pyramidal cell layers of CA1 to CA3 area.The counterstaining showed that rAd5 mainly transduced neuronal precursor cells in the SGZ of the hippocampus and rarely transduced neurons in the GCL.Conclusion The rAd5-mediated gene transfer is rapid and efficient and can keep for a long time in suitable titre; moreover,rAd5 has a highly specific tropism with the neuronal precursor cells in the SGZ of the hippocampus in mice.