Gene therapy with an improved doxycycline regulated plasmid encoding a TNFalpha inhibitor in experimental arthritis

Gould DJ, Yousaf N, Fatah R, Subang MC, Chernajovsky Y
Source: Arthritis Res Ther
Publication Date: (2007)
Issue: 9(1): R7
Research Area:
Cancer Research/Cell Biology
Cells used in publication:
Species: mouse
Tissue Origin: skeletal muscle
Nucleofector® I/II/2b
Inhibition of TNFalpha with biological molecules has proven an effective treatment for rheumatoid arthritis achieving a 20% improvement in ACR score in up to 65% of patients. The main drawback to these and many other biological treatments has been their expense, which has precluded their widespread application. Biological molecules could alternatively be delivered by gene therapy as the encoding DNA. We have developed novel plasmid vectors termed pGTLMIK and pGTTMIK from which luciferase and a dimeric TNFRII (dTNFR) are respectively expressed in a doxycycline (Dox) regulated manner. Regulated expression of luciferase from the self-contained plasmid pGTLMIK was examined in vitro in a variety of cell lines and in vivo following intramuscular delivery with electroporation in DBA/1 mice. Dox regulated expression of luciferase from pGTLMIK was in the region of 1000 fold was demonstrated in vitro and efficient regulation was observed in vivo. The vector pGTTMIK encoding dTNFR was delivered by the same route to mice with collagen-induced arthritis with and without administration of Dox. When pGTTMIK was delivered after the onset of arthritis, progression of the disease in terms of both paw thickness and clinical score was inhibited when Dox was also administered. Vectors with similar regulation characteristics may be suitable for clinical application.