Objective: To determine the efficacy of local therapy with human angiostatin gene in murine collagen-induced arthritis (CIA).
Methods: DBA/1 mice were immunized with bovine type II collagen. Before the onset of arthritis, NIH3T3 fibroblasts, transduced with angiostatin-expressing retroviral vectors or control vectors, were transplanted into the knee cavity. The incidence of arthritis in the knee joints was evaluated histologically based on pannus formation and cartilage destruction. Paws were evaluated macroscopically for redness, swelling, and deformities and immunologically for levels of interleukin-1 beta. Angiogenesis in paws and knee joints was studied by immunohistochemistry using anti-CD31 antibody and measurement of von Willebrand factor levels.
Results: Pannus formation and cartilage erosion were dramatically reduced in knees transplanted with angiostatin-expressing cells. In addition, the onset of CIA in the ipsilateral paws below the knees injected with the angiostatin gene was significantly prevented. Furthermore, angiostatin gene transfer inhibited arthritis-associated angiogenesis.
Conclusion: Local production of angiostatin in the knee was able to prevent the onset of CIA not only in the knee injected with genetically engineered cells, but also in the uninjected ipsilateral paw. This suggests that transfer of the angiostatin gene, and potentially also its protein, may provide a new, effective approach to the treatment of rheumatoid arthritis.