Arsenic trioxide is a novel agent for combination therapy to prolong heart allograft survival in allo-primed T cells transferred mice

► The accelerated rejection will be prevented by the combination therapy with As2O3. ► The combination therapy inhibits the Th1 immunity and function of memory T cells. ► This combination will increase the secretion of TGF-β and generation of Tregs. ► The protective effect is due to both clonal anergy and a gain of regulatory cells.