Mesenchymal stem cells: Emerging mechanisms of immunomodulation and therapy

Core Tip

Core tip: Mesenchymal stem cells (MSCs) comprise a mixture of different stromal cell types that display remarkable pleiotropic properties, including those of anti-apoptosis, angiogenesis, growth factor production, anti-fibrosis, and chemo-attraction. It is because of these diverse biological properties that these cells have been intensively studied in the hopes of their utilization as a platform of cellular therapy in disease settings. Early experimental and preclinical studies focused on their stem cell renewal, differentiation, and regenerative properties for potential use in degenerative diseases of mesenchymal origin. Afterwards, MSCs were found to increase the success of bone marrow transplantation, reduce rejection of engrafted tissues, and display remarkable anti-inflammatory properties. Currently, much work centers on the immune-modulatory facets of MSCs, especially in reducing inflammation and suppressing immune cell function in preclinical injury and autoimmune disease settings. However, emerging reports suggest a multifunctional quality to MSC immune-modulation. This review dissects MSC manipulation of immune responses, which result in either immunosuppression or immuno-stimulation.