IL-22-dependent dysbiosis and mononuclear phagocyte depletion contribute to steroid-resistant gut graft-versus-host disease in mice.

Song, Qingxiao; Wang, Xiaoning; Wu, Xiwei; Kang, Tae Hyuk; Qin, Hanjun; Zhao, Dongchang; Jenq, Robert R; van den Brink, Marcel R M et al. · Nat Commun · 2021

basic_science · Level V

Where this comes from

Abstract

Efforts to improve the prognosis of steroid-resistant gut acute graft-versus-host-disease (SR-Gut-aGVHD) have suffered from poor understanding of its pathogenesis. Here we show that the pathogenesis of SR-Gut-aGVHD is associated with reduction of IFN-γ<sup>+</sup> Th/Tc1 cells and preferential expansion of IL-17<sup>-</sup>IL-22<sup>+</sup> Th/Tc22 cells. The IL-22 from Th/Tc22 cells causes dysbiosis in a Reg3γ-dependent manner. Transplantation of IFN-γ-deficient donor CD8<sup>+</sup> T cells in the absence of CD4<sup>+</sup> T cells produces a phenocopy of SR-Gut-aGVHD. IFN-γ deficiency in donor CD8<sup>+</sup> T cells also leads to a PD-1-dependent depletion of intestinal protective CX3CR1<sup>hi</sup> mononuclear phagocytes (MNP), which also augments expansion of Tc22 cells. Supporting the dual regulation, simultaneous dysbiosis induction and depletion of CX3CR1<sup>hi</sup> MNP results in full-blown Gut-aGVHD. Our results thus provide insights into SR-Gut-aGVHD pathogenesis and suggest the potential efficacy of IL-22 antagonists and IFN-γ agonists in SR-Gut-aGVHD therapy.

Medical subject headings