Adhesion molecules: key players in Mesenchymal stem cell-mediated immunosuppression.

Adhesion molecules are known to be important components of an active T cell-mediated immune response. Signals generated at a site of inflammation cause circulating T-cells to respond by rolling, arrest, and then transmigration through the endothelium, all of which are mediated by adhesion molecules. Consequently, strategies have been developed to treat immune disorders with specific antibodies that block the interaction of adhesion molecules. However, the therapeutic effects of such remedies are not always achieved. Our recent investigations have revealed that intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) work together with chemokines to induce immunosuppression mediated by mesenchymal stem cells (MSCs), thus demonstrating the dual role of adhesion molecules in immune responses. Since MSCs represent an important component of the stromal cells in an inflammatory microenvironment, our findings provide novel information for understanding the regulation of immune responses and for designing new strategies to treat immune disorders.