RAPID COMMUNICATION Pretreatment of Donor Mice With Granulocyte Colony-Stimulating Factor Polarizes Donor T Lymphocytes Toward Type-2 Cytokine Production and Reduces Severity of Experimental Graft-Versus-Host Disease

The incidence and severity of acute graft-versus-host disease (GVHDJ after allogeneic transplantation using peripheral blood progenitor cells mobilized by granulocyte colonystimulating factor (G-CSF) appear t o be no worse than those after bone marrow transplantation, despite the presence of large numbers of T cells in the donor infusion. Experimental studies have shown that type-l T cells (secreting interleukin2 [IL-21 and interferon-y) mediate acute GVHD, whereas type9 T cells (secreting IL-4 and IL-IO) can prevent acute GVHD. We tested the hypothesis that G-CSF modulates Tcell function toward a type-2 response and thus reduces the severity of acute GVHD. B6 mice were injected with G-CSF or diluent for 4 days, and their splenic T cells were stimulated in vitro with alloantigen or mitogen in the absence of GCSF. T cells from G-CSF-treated mice showed a significant