Immune-adhesion molecules in the prevention of allograft rejection and reperfusion injury

Control of the immune system is of indispensable importance for graft accep tance and function. Immunological changes in the graft before and after org an harvesting, the transplantation procedure itself and the organ recipient s clinical state contribute to the immune response. Leukocyte trafficking [ 1] into a graft is regulated by various signal transducing molecules, which have been characterised during the past years. Ligand molecules on endothe lial cells and in the organ parenchyma are the counterparts for leukocyte a dhesion and tissue infiltration. The expression of these ligand molecules i s regulated by soluble factors and cell-cell interactions [2]. The regulati on of tissue inflammation and repair mechanisms involving components of the immune system therefore depends on a number of cell-surface interactions. The processes of intravascular adhesion, transmigration and infiltration by leukocytes and platelets are mainly mediated by receptor ligand interactio ns with target cells (cell-cell) and extracellular matrix proteins (cell-ma trix). The main molecular families of adhesion receptor/ligand molecules ha ve been identified. Today, we are still far from understanding this network of interactions. The numbers of molecules and factors involved are still i ncreasing. This review summarises the currently available knowledge on the intervention in this system by monoclonal antibodies (mAbs), peptides and b locking agents. From this review, it is evident that further investigations are justified.