Recipient interleukin-1β production is critical for lung allograft acceptance

We observed that human and mouse neutrophils from lung transplant recipients suppress T cell responses in an NO-dependent fashion. Finally, recipients deficient in Il1b, but not Tnfa or Il6, acutely rejected lung allografts despite receiving immunosuppression that results in tolerance when administered to wildtype hosts. Thus, contrary to the widely held notion that proinflammatory cytokines promote deleterious outcomes after transplantation, our findings uncovered a previously unknown role for recipient IL-1β as a critical mediator of pulmonary allograft acceptance.

Our findings inform future studies developing lung-specific immunosuppressive strategies.