What Part Can Mesenchymal Stem Cells Play in Transplantation Tolerance Induction?

Abstract

ell therapy and regenerative medicine have emergedover recent years and are proving to be exciting areasof biochemical research. These proceedings summarize theSeventh Beaune Seminar in Transplantation Research that wasonceagaindevotedtotransplantationtoleranceinduction.Speakersatthisseminarfocusedtheirpresentationsonthepotential clinical applications of mesenchymal stem cells(MSC)intoleranceinductionforbothorganandhemato-poietic transplantations.MSCaretheprogenitorsofmultiplemesenchymallin-eages (bone, cartilage, muscle, fat tissue, and marrowstroma). Adult bone marrow and fat tissue are both richsources of human MSC.Although the immune regulatory properties of MSChave been clearly demonstrated both in vitro and in vivo,theyare not inherently immunogenic. For instance, inthe context of allogeneic hematopoietic stem-cell trans-plantation, the co-infusion of hematopoietic stem cellsand MSC promotes a rapid hematologic reconstitution.Both in animal models and in clinical settings, this co-infusion may well explain the reduced incidence of graftversus host disease. On the other hand, a possible effect ofMSC on organ transplant survival remains questionable,and justifies further investigations. Interestingly, clinicalcomplicationshavenotbeenreportedafterthistypeofcelltherapy.The seventh seminar was divided into three parts: thefirst covered the classification and the function of MSC(homing, differentiation potential, immunomodulary prop-erties);inthesecondpart,speakersspokeabouttheengineer-ingofMSCforcelltherapyinthetransplantationsetting,andthe third part focused on clinical approaches for measuringthe impact of MSC on graft survival and donor-specific tol-erance induction.International speakers led a stimulating discussionwiththeattendees(physiciansandresearchworkers).Wesin-cerelyhopethatreaderswillappreciatethisprospectivereflexion.