Local delivery of beta interferon using an adeno-associated virus type 5 effectively inhibits adjuvant arthritis in rats.

Beta interferon (IFN-beta) is a cytokine with potent immunomodulatory properties and has been described as a promising therapeutic molecule for the treatment of rheumatoid arthritis (RA). IFN-beta was previously overexpressed intra-articularly using an adenoviral vector in rats with adjuvant arthritis (AA) as a model of RA. This effect was powerful, albeit transient due to the vector chosen. Therefore, in the context of pre-clinical development, a delivery vector optimized for intra-articular gene transfer, recombinant adeno-associated virus type 5 (rAAV5), was selected. To exert an optimal effect, protein production should parallel the course of the disease. For this reason, the gene for IFN-beta was placed under the control of an inflammation-responsive [nuclear factor (NF)-kappaB] promoter. After intra-articular injection of the rAAV5 constructs in rats with AA, local transcription of the transgene and production of the IFN-beta protein was found, leading to a pronounced and sustained effect on paw swelling when the expression was under the control of the NF-kappaB-responsive promoter. Additionally, a significant beneficial effect was observed on proteoglycan depletion and erosions. Thus, intra-articular overexpression of IFN-beta using a rAAV5 vector exhibits potential as an innovative therapy for the treatment of RA.

Reduction of arthritis following intra-articular administration of an adeno-associated virus serotype 5 expressing a disease-inducible TNF-blocking agent.

BACKGROUND: In the context of preclinical development, we studied the potential of intra-articular gene delivery using a recombinant adeno-associated virus 5 (rAAV5) encoding a chimeric human tumour necrosis factoralpha (TNFalpha) soluble receptor I linked to a mouse immunoglobulin heavy chain Fc portion (TNF receptor I; TNFRI-Ig). METHODS: Expression was under control of a nuclear factor kappa B (NFkappaB)-responsive promoter and compared with a cytomegalovirus (CMV) promoter (rAAV5.NFkappaB-TNFRI-Ig and rAAV5.CMV-TNFRI-Ig, respectively). RESULTS: Fibroblast-like synoviocytes transduced in vitro with rAAV5.NFkappaB-TNFRI-Ig were able to produce TNFRI-Ig protein in response to several stimuli, and this was inhibited upon treatment with a specific NFkappaB blocking agent. A bioassay revealed that the synthesised TNFRI-Ig was bioactive, showing a higher affinity for human than for rat TNFalpha. Transcription of the transgene and protein production were detectable in joints injected with both constructs. No dissemination of the vector was observed outside the joints. A significant reduction in paw swelling was seen in rats treated with rAAV5.NFkappaB-TNFRI-Ig. This clinical effect was accompanied by a decrease in pro-inflammatory cytokine levels and an increase in IL10 expression in the synovium. CONCLUSION: These results provide evidence that intra-articular gene therapy using rAAV5 encoding TNFRI-Ig may be a safe and feasible approach for the treatment of rheumatoid arthritis. The higher affinity for human TNFalpha suggests that in patients with rheumatoid arthritis the therapeutic effect might be even more pronounced than in rat adjuvant arthritis.