STAT3 signaling in CD4+ T cells is critical for the pathogenesis of chronic sclerodermatous graft-versus-host disease in a murine model

V Radojcic, MA Pletneva, HR Yen, S Ivcevic… - The journal of …, 2010 - journals.aai.org
V Radojcic, MA Pletneva, HR Yen, S Ivcevic, A Panoskaltsis-Mortari, AC Gilliam, CG Drake
The journal of immunology, 2010journals.aai.org
Donor CD4+ T cells are thought to be essential for inducing delayed host tissue injury in
chronic graft-versus-host disease (GVHD). However, the relative contributions of distinct
effector CD4+ T cell subpopulations and the molecular pathways influencing their
generation are not known. We investigated the role of the STAT3 pathway in a murine model
of chronic sclerodermatous GVHD. This pathway integrates multiple signaling events during
the differentiation of naive CD4+ T cells and impacts their homeostasis. We report that …
Abstract
Donor CD4+ T cells are thought to be essential for inducing delayed host tissue injury in chronic graft-versus-host disease (GVHD). However, the relative contributions of distinct effector CD4+ T cell subpopulations and the molecular pathways influencing their generation are not known. We investigated the role of the STAT3 pathway in a murine model of chronic sclerodermatous GVHD. This pathway integrates multiple signaling events during the differentiation of naive CD4+ T cells and impacts their homeostasis. We report that chimeras receiving an allograft containing STAT3-ablated donor CD4+ T cells do not develop classic clinical and pathological manifestations of alloimmune tissue injury. Analysis of chimeras showed that abrogation of STAT3 signaling reduced the in vivo expansion of donor-derived CD4+ T cells and their accumulation in GVHD target tissues without abolishing antihost alloreactivity. STAT3 ablation did not significantly affect Th1 differentiation while enhancing CD4+ CD25+ Foxp3+ T cell reconstitution through thymus-dependent and-independent pathways. Transient depletion of CD25+ T cells in chimeras receiving STAT3-deficient T cells resulted in delayed development of alloimmune gut and liver injury. This delayed de novo GVHD was associated with the emergence of donor hematopoietic stem cell-derived Th1 and Th17 cells. These results suggest that STAT3 signaling in graft CD4+ T cells links the alloimmune tissue injury of donor graft T cells and the emergence of donor hematopoietic stem cell-derived pathogenic effector cells and that both populations contribute, albeit in different ways, to the genesis of chronic GVHD after allogenic bone marrow transplantation in a murine model.
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