A colitogenic memory CD4⁺ T cell population mediates gastrointestinal graft-versus-host disease

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Abstract

Damage to the gastrointestinal tract is a major cause of morbidity and mortality in graft-versus-host disease (GVHD) and is attributable to T cell–mediated inflammation. In this work, we identified a unique CD4⁺ T cell population that constitutively expresses the β₂ integrin CD11c and displays a biased central memory phenotype and memory T cell transcriptional profile, innate-like properties, and increased expression of the gut-homing molecules α₄β₇ and CCR9. Using several complementary murine GVHD models, we determined that adoptive transfer and early accumulation of β₂ integrin–expressing CD4⁺ T cells in the gastrointestinal tract initiated Th1-mediated proinflammatory cytokine production, augmented pathological damage in the colon, and increased mortality. The pathogenic effect of this CD4⁺ T cell population critically depended on coexpression of the IL-23 receptor, which was required for maximal inflammatory effects. Non–Foxp3-expressing CD4⁺ T cells produced IL-10, which regulated colonic inflammation and attenuated lethality in the absence of functional CD4⁺Foxp3⁺ T cells. Thus, the coordinate expression of CD11c and the IL-23 receptor defines an IL-10–regulated, colitogenic memory CD4⁺ T cell subset that is poised to initiate inflammation when there is loss of tolerance and breakdown of mucosal barriers.

Authors

Vivian Zhou, Kimberle Agle, Xiao Chen, Amy Beres, Richard Komorowski, Ludovic Belle, Carolyn Taylor, Fenlu Zhu, Dipica Haribhai, Calvin B. Williams, James Verbsky, Wendy Blumenschein, Svetlana Sadekova, Eddie Bowman, Christie Ballantyne, Casey Weaver, David A. Serody, Benjamin Vincent, Jonathan Serody, Daniel J. Cua, William R. Drobyski