G-CSF-treated donor CD4+ T cells attenuate acute GVHD through a reduction in Th17 cell differentiation

► G-CSF-treated donor CD4+ T cells attenuated the skin GVHD. ► G-CSF-treated donor CD4+ T cells reduced Th17 responses after transplantation. ► G-CSF-treated donor CD4+ T cells increased SOCS3 expression. ► The mechanism explains the effect of G-CSF on CD4+ T cell-mediated acute GVHD.