The gene delivery system for rheumatoid synovium.

A gene therapy of synovial tissue is potentially a novel therapeutic method in rheumatoid arthritis (RA). The method induces expression of anti-arthritic molecules in target cells, and is also useful for the investigation of novel therapeutic targets in vitro. Previous studies showed that viral vectors, which can infect non-proliferative cells well, i.e. adenovirus-based vector, were effective in gene transfer to synovial tissue. In this review, we discuss the properties and effectiveness of these methods and our investigations in forcing expression in synovial tissue or cells. The methods of gene transfer are classified into two categories : virus vectors and virus-free vectors. The virus vectors seem to be more applicable to clinical approaches since clinical trials of adeno-associated virus mediated gene therapy were performed in 2007. At the same time, many effective novel virus-free vectors have been developed. Although these gene transfer technologies still have to be improved more to warrant their safety, the gene therapy is an ideal technique in performing "Bench to Clinic and Clinic to Bench" research studies. We hope that it will be applied to RA therapy in near future.