One approach to the treatment of intra-articular pathologies involves the transfer of genes to synovium and their intrasynovial expression [1
]. The development of technologies with which to do this not only opens new therapeutic possibilities but also permits the study of selected gene products within the synovial microenvironment. Here we review briefly the results obtained from such investigations.
Most of these data have been obtained using the rabbit knee as a model. This joint has the advantage of being large enough for efficient intra-articular injection and serial lavage. Moreover, after euthanasia the various intra-articular tissues can be dissected and independently studied ex vivo.
We utilize gene delivery to the joint in two complimentary approaches to the study of joint diseases. In the first, genes whose products have been associated with arthritis are introduced into the synovium of a normal joint to determine whether their gene products can provoke synovitis or other joint disturbances. In the second, the genes are introduced into inflamed joints to determine whether their products have anti-inflammatory properties. Antigen-induced arthritis (aia), using ovalbumin as the inciting antigen, is often employed for these experiments.