Recipient IL-33 stimulates donor T cells to promote Type 1 alloimmunity and lethal acute GVHD (TRAN1P.931)

• Published in: The Journal of immunology (1950) 2015-05, Vol.194 (1_Supplement), p.140-140.13
• Main Authors: Matta, Benjamin, Reichenbach, Dawn, Schwarze, Vincent, Tkachev, Victor, Mathews, Lisa, Liu, Quan, Warncke, Max, Ferrara, James, Zeiser, Robert, Blazar, Bruce, Turnquist, Heth
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.194.Supp.140.13

Graft-versus-host disease (GVHD) is a severe and often fatal complication of allogeneic (allo) hematopoietic cell transplantation (HCT). Total body irradiation (TBI) conditioning of the recipient and subsequent GVHD-associated alloimmune responses cause significant gut epithelial cell damage. As IL-33 is an epithelial cell-derived cytokine with pleiotropic functions, we investigated the impact of IL-33 on GVHD pathogenesis. Mice received TBI and alloHCT (allogeneic bone marrow (BM) +/- T cells). Where indicated, recipient mice, donor BM or T cells were deficient for IL-33 or its receptor, ST2. Survival, weight, and clinical score were monitored. Tissues and serum were harvested for IL-33 quantitation and analysis of alloimmune responses. We find that IL-33 expression is increased rapidly in CD45- cells of the gut after TBI, and sustained at least through day 14 in alloHCT recipients. Recipient, but not donor, IL-33 acting on ST2-expressing donor T cells fueled Type 1 responses and GVHD. The IL-33 antagonist ST2-Fc prevented GVHD and reduced Type 1 alloimmune responses, whereas IL-33 administration post-alloHCT (d+3 to d+7) accelerated GVHD lethality and Type 1 alloimmunity. These potent responses overcome regulatory functions of IL-33 to promote GVHD. In summary, our findings are the first to reveal a detrimental role for IL-33 underlying GVHD pathogenesis and establish the IL-33/ST2 axis as a targetable pathway to lessen the risk of GVHD following alloHCT.