Acute graft-versus-host disease (GVHD) represents a severe, T cell–driven inflammatory complication following allogeneic hematopoietic cell transplantation (allo-HCT). GVHD often affects the intestine and is associated with a poor prognosis. Although frequently detectable, proinflammatory mechanisms exerted by intestinal tissue–infiltrating Th cell subsets remain to be fully elucidated. Here, we show that the Th17-defining transcription factor basic leucine zipper transcription factor ATF-like (BATF) was strongly regulated across human and mouse intestinal GVHD tissues. Studies in complete MHC-mismatched and minor histocompatibility–mismatched (miHA-mismatched) GVHD models revealed that BATF-expressing T cells were functionally indispensable for intestinal GVHD manifestation. Mechanistically, BATF controlled the formation of colon-infiltrating, IL-7 receptor–positive (IL-7R+), granulocyte-macrophage colony-stimulating factor–positive (GM-CSF+), donor T effector memory (Tem) cells. This T cell subset was sufficient to promote intestinal GVHD, while its occurrence was largely dependent on T cell–intrinsic BATF expression, required IL-7–IL-7R interaction, and was enhanced by GM-CSF. Thus, this study identifies BATF-dependent pathogenic GM-CSF+ effector T cells as critical promoters of intestinal inflammation in GVHD and hence putatively provides mechanistic insight into inflammatory processes previously assumed to be selectively Th17 driven.
Evelyn Ullrich, Benjamin Abendroth, Johanna Rothamer, Carina Huber, Maike Büttner-Herold, Vera Buchele, Tina Vogler, Thomas Longerich, Sebastian Zundler, Simon Völkl, Andreas Beilhack, Stefan Rose-John, Stefan Wirtz, Georg F. Weber, Sakhila Ghimire, Marina Kreutz, Ernst Holler, Andreas Mackensen, Markus F. Neurath, Kai Hildner