Fig. 1.

Diagram representing the probable mechanisms of IL-33/ST2 signaling in liver transplantation. Constitutively expressed IL-33 is released upon liver damage and binds to either the ST2/IL-1 receptor accessory protein (IL-1RAP) heterodimer, recruiting MyD88 to its intracellular domain, or the sST2 decoy receptor, which does not signal. Through NF-κB and Foxp3 activation, IL-33 enhances Th2-associated cytokines and promotes Treg differentiation, which induces alloimmune suppression and graft tolerance