Studies on infiltrating host cells harvested from acutely rejecting rat cardiac allografts.

Although the cellular events of rejection of organ allografts have been fully described histologically, little information exists regarding actual mechanisms of graft destruction. Available concepts are based primarily upon assays performed in vitro. This study describes a model designed to correlate such in vitro information with events occurring in vivo within acutely rejecting organ allografts. Infiltrating host cells had been harvested by two techniques from heterotopic cardiac allografts in rats. The various cell classes have been noted and their differential rates of accumulation compared to serial histological observations. Subpopulations of cells have been identified by surface markers, and specific cytotoxicity against donor alloantigen has been determined as a T lymphocyte function. These techniques may be of aid in unraveling the complexities of graft rejection.