Wnt/β-catenin regulates alloreactive T cells for the treatment of hematological malignancies

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most widely applied forms of adaptive immunotherapy. Both the detrimental graft-versus-host disease (GVHD) and the beneficial graft-versus-leukemia (GVL) effects occurring after allo-HSCT are largely mediated by alloantigen-reactive donor T cells in the graft. Separating GVHD from GVL effects is a formidable challenge, and a greater understanding of donor T cell biology is required to accomplish the uncoupling of GVHD from GVL. Here, we tested a novel mouse model of {beta}-catenin (Cat-Tg) in an allo-HSCT model. Our data show that T cells from Cat-Tg mice did not cause GVHD. Surprisingly, Cat-Tg T cells maintained the GVL effect. Donor T cells from Cat-Tg mice exhibited significantly lower inflammatory cytokine production and reduced donor T cell proliferation, while upregulating cytotoxic mediators that resulted in enhanced cytotoxicity. RNA sequencing data revealed changes in the expression of over 150 genes for CD4, and over 250 genes for CD8+T cells involved in essential aspects of immune response and GVHD pathophysiology. Transgenic over-expression of human {beta}-catenin primarily affects CD8+ T cell phenotype. Altogether, our data suggest that {beta}-catenin is a druggable target for developing therapeutic strategies to reduce GVHD while preserving the beneficial GVL effects following allo-HSCT treatment.