ABSTRACT
E ndothelial cells forming the interface between donor and recipient are the first donor cells to be recognized by the host s immune system. This fact plus the observation that they are highly responsive to cytokines and express numerous molecules which interact with ligands on lymphocytes (Tables 3 .1 ,3 .2) has stimulated much research into their precise role in transplant rejection. It is our view that endothelial cells are pivotal both in controlling the egress of inflamma tory cells into the allografted organ but also as specific antigen presenting cells, by present ing foreign molecules to the immune (Fig. 3.1).