ABSTRACT
Tissues that are mismatched for major histocompatibility complex (MHC) molecules can induce uniquely strong primary immune responses in vitro, as reflected by the mixed lymphocyte reaction (MLR), and provoke allograft rejection, graftversus-host disease (GVHD), and the graft-versus-leukemia effect (GVL) in vivo. In fact, the investigation of the targets of the immune responses to allografts led to the discovery of MHC molecules, which were initially called transplantation antigens.
