Developments in our comprehension of the autoimmune and inflammation mechanisms in rheumatoid arthritis (RA) have produced targeted therapies that block aberrant immune cells and cytokine networks, and improved treatment of RA patients considerably. Nevertheless, limitations of these treatments include incomplete treatment response, adverse effects requiring drug withdrawal, and refractory cases. Hence, many researchers have redirected efforts towards investigation of other biological aspects of RA, including the mechanisms driving joint tissue repair and balanced immune regulation. This investigation focuses on mesenchymal stem cell (MSC) research, with the ultimate goal of developing interventions for immune modulation and repair of damaged joints. MSCs are multipotent cells capable of differentiating into mesodermal lineage cells. These cells have also attracted interest for their anti-inflammatory and immunomodulatory capacities. They have many distinctive immunological properties, inhibiting the proliferation and production of cytokines by T, B, natural killer, and dendritic cells. Indeed, MSCs have the capacity to regulate immunity-induced peripheral tolerance, suggesting they can be used as therapeutic tools in RA. This review discusses properties of MSCs, in vitro studies, animal studies, and clinical trials involving MSCs. Our review discusses the current knowledge of the mechanisms of MSC-mediated immunosuppression and potential therapeutic uses of MSCs in RA.

Keywords: Inflammation, Mesenchymal stem cells, Rheumatoid arthritis