Enhanced transgene expression in the mouse skeletal muscle infected by the adeno-associated viral vector with the human elongation factor 1α promoter and a human chromatin insulator

✍ Scribed by Mayuyo Mori-Uchino; Takamasa Takeuchi; Isao Murakami; Tetsu Yano; Toshiharu Yasugi; Yuji Taketani; Keiichi Nakagawa; Tadahito Kanda

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 215 KB
• Volume: 11
• Category: Article
• ISSN: 1099-498X
• DOI: 10.1002/jgm.1337

✦ Synopsis

Abstract

Background

Efficient and continuous expression of a therapeutic transgene is a key factor for improving the efficacy of gene therapy. Some insulators are known to contribute to continuous high‐level expression of a therapeutic transgene.

Methods

Using the human AAVS1 insulator (DHS) found in the AAVS1 DNase I hypersensitive site, chicken β‐globin insulator (cHS4) and sea urchin arylsufatase insulator (Ars), we newly constructed three recombinant adeno‐associated virus vectors (rAAV) and examined their capability of transducing the mouse quadriceps muscle.

Results

DHS increased transgene expression from the human elongation factor 1α promoter (EF) by 1000‐fold, up to the high level achieved by the human cytomegalovirus immediate early promoter/enhancer (CMV), which comprises an extremely strong promoter for driving a transgene. cHS4 enhanced the expression by 100‐fold, whereas Ars did not. The enhanced expression was maintained for at least 24 weeks. Vector copy numbers were similar with and without DHS or cHS4; thus, the enhancement is most likely due to up‐regulated transcription. Neither DHS, nor cHS4 affected transgene expression from CMV. DHS enhanced expression from the human muscle creatine kinase promoter/enhancer by 100‐fold in mice, as did DHS from EF.

Conclusions

Although DHS was unable to further enhance high expression from the strong viral enhancer/promoter, it enhanced low expression from the human promoters by 100‐ to 1000‐fold. Thus, DHS may be useful for constructing rAAVs that express a therapeutic transgene from less efficient, tissue specific promoters. Copyright © 2009 John Wiley & Sons, Ltd.