The general aim of the present study is to test a cell therapy with autologous ex-vivo expanded mesenchymal stromal cells (MSCs) as a strategy to induce tolerance in living-donor kidney transplant recipients. MSCs will be prepared accordingly to established protocols, starting from bone marrow explants of living-donor kidney transplant recipients obtained 3-4 months before kidney transplant. From these samples, MSCs will be expanded in Good Manufacturing Practice (GMP) approved facilities and used for the present study in patients undergoing kidney transplantation.