Experimental Animal Models for Rheumatoid Arthritis: Methods and Applications

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by synovitis and joint damage. The etiology of RA is multi-factorial including various genetic and environmental factors, and the pathogenesis is complex involving lymphocyte infiltration, synovial cell proliferation, pannus formation, and cartilage and bone destruction. Various animal models have been used to study potential etiopathogenetic mechanisms in RA. They are also extensively used to test new potential therapeutic agents. Despite some limitations, those animal models have significantly progressed our understanding of the basic mechanisms and have contributed to several current major advances in the treatment of RA. These models include the induced arthritis models such as collagen-induced arthritis (CIA), antibody-induced arthritis, the genetically manipulated or spontaneous arthritis models, and humanized mouse models. The choice regarding the proper model should be performed carefully, taking into account the biology of the animal model and the therapeutic target under evaluation in order to make better predictions of efficacy in human RA. Thus, in this review, we describe important mouse models of RA, focusing on the underlying mechanisms, methods, advantages and limitations, and usefulness.