Strategies for gene delivery and treatment of rheumatoid arthritis.

摘要

Rheumatoid Arthritis (RA) is an autoimmune disease with no known etiology, which causes chronic erosive synovitis in the peripheral joints and leads to pain and disability. RA affects 1–2% of the population worldwide. Although conventional pharmacologic therapies and surgical interventions provide temporary relief from pain, they are ineffective in stopping the progression of disease or restoring bone function. Failure of treatment by traditional methods has led to the pursuit of novel remedial techniques such as gene therapy. Direct gene transfer of immunomodulatory cytokines to the synovium would lead to accumulation of the anti-arthritic product in and around the diseased tissue, maximizing its effect, reducing potential side effects and circumventing repeat dosing.; Several pro- and anti-inflammatory cytokines play an important role in the pathophysiology of RA. IL-10 is a key protein in the anti-inflammatory response. Human IL-10 is anti-inflammatory as well as immunostimulatory, whereas vIL-10, the viral homologue of hIL-10, is only anti-inflammatory. The immunostimulatory characteristic of hIL-10 is attributed to isoleucine at position 87, (which in vIL-10 is alanine). Isoleucine was substituted with alanine (I87A) in hIL-10, leaving the biologically active mutant human IL-10 with immunosuppressive activity and a potential for being a superior therapeutic for inflammatory disorders. In Chapter I, I have compared the therapeutic efficacy of adenovirally delivered hIL-10, vIL-10 and mut.hIL-10 in the antigen induced arthritis (AIA) rabbit model.; IL-6, a pleiotropic cytokine, plays a role in regulating the immune response. IL-6 acts on target cells via its receptor consisting of two transmembrane glycoproteins: the ligand binding α-receptor—IL6R and the signal transducer—gp130. The IL-6/IL-6R complex triggers homodimerization of gp130 activating signal transduction. IL-6 plays an important but controversial role in the progression of RA. In Chapter II, I have evaluated the efficacy of SuperIL-6, a biologically active fusion protein of IL-6 and sIL-6R, to block the progression of RA. SuperIL-6 was delivered intra-articularly using a replication defective adenovirus, in naive and AIA rabbits.; Although viral-based vectors have shown potential as gene-delivery vehicles, there are limiting factors such as specificity, infectivity and immunogenecity. The advent of DNA-transposon systems has presented the opportunity for transposon-tagged delivery and stable transgene integration in host chromosomes. Himar1 , a reconstructed active transposon, belonging to the Tc1/ mariner superfamily, has been used as a prokaryotic genetic tool but has not been as successful in eukaryotes due to its low level of activity. In Chapter III, I evaluated the potential of a 50-fold hyperactive mutant mariner transposase, C9, in combination with a miniHimar1 transposon as a gene delivery vehicle in vitro as well as in vivo.