Inflammatory Cytokine-Induced Intercellular Adhesion Molecule-1 and Vascular Cell Adhesion Molecule-1 in Mesenchymal Stem Cells Are Critical for Immunosuppression

Cell-cell adhesion mediated by ICAM-1 and VCAM-1 is critical for T cell activation and leukocyte recruitment to the inflammation site and, therefore, plays an important role in evoking effective immune responses. However, we found that ICAM-1 and VCAM-1 were critical for mesenchymal stem cell (MSC)-mediated immunosuppression. When MSCs were cocultured with T cells in the presence of T cell Ag receptor activation, they significantly upregulated the adhesive capability of T cells due to the increased expression of ICAM-1 and VCAM-1. By comparing the immunosuppressive effect of MSCs toward various subtypes of T cells and the expression of these adhesion molecules, we found that the greater expression of ICAM-1…