Gene therapy of rheumatoid arthritis via cytokine regulation: future perspectives.

Following many years of research using isolated human tissues and animal models, sufficient knowledge concerning rheumatoid arthritis has accumulated so that novel immunotherapies have been proposed. Biological agents are being tested in clinical trials and include antibodies to T cells and cytokines. Currently the most promising of these is intravenously administered neutralizing anti-TNF antibody. In order to establish disease modification, however, therapy needs to be delivered continuously over the long term. The prospect of delivering cytokine inhibitors as genetic material (naked DNA), viruses or in engineered autologous cells is considered as one option for achieving this goal. We compare two strategies, firstly, using immobile cells such as fibroblasts, myoblasts or keratinocytes, and secondly, the migratory cells of the immune system. The former provides a reservoir of systemic delivery of the therapeutic protein whereas the latter provides targeted delivery determined by the antigen specificity of the immune cells. Early validation has begun in animal models of rheumatoid arthritis.