Characterization of regulatory T cells in neonatally induced cardiac allograft acceptance

Heart transplantation in our days has become an accepted therapy for end stage heart failure. However, decreasing numbers of donor organs and lifelong immunosuppressive therapy with undesirable side-effects for graft and recipient enforce the need for new treatment strategies. Therefore developing a protocol leading to acceptance of grafts from any potential organ donor without global immunodeficiency or immunosuppression is a major goal in transplant-related research.; Our previous work demonstrated a novel pattern of 'non-donor-specific' cardiac allograft acceptance induced in mice injected as neonates with allogeneic fetal liver cells.; This project was aimed to explore in more detail this unexpected pattern of third-party cardiac allograft acceptance.; Our work shows that in this setting transferable CD4 +CD25+Foxp3+ T cells mediate unrelated cardiac graft acceptance in a dose- and cell-contact-dependent manner. These regulatory cells seem to be induced by the cardiac graft and appear to mediate in vivo acceptance of cardiac tissue specifically.