Recipient pretreatment with mammalian IL-10 prolongs mouse cardiac allograft survival by inhibition of anti-donor T cell responses

IL-10 is considered an immunosuppressive cytokine due to its capacity to inhibit production of proinflammatory cytokines and the maturation of antigen-presenting cells (APC). It has been shown, however, that systemic administration of recombinant (r) mouse (m) IL-10 at a dose of 100 mg/d for 7 days after heart allograft transplantation can accelerate graft rejection and reverse the immunosuppressive effect of cyclosporine (CsA). Other recent reports have also challenged an immunosuppressive role of mammalian IL-10. These findings suggest a complex regulatory effect of IL-10 on immune responses. The goal of this study was to further understand the influence of IL-10 on alloresponses.