Donor-type CD4+CD25+ Regulatory T Cells Suppress Lethal Acute Graft-Versus-Host Disease after Allogeneic Bone Marrow Transplantation

Acute graft-versus-host disease (aGVHD) is still a major obstacle in clinical allogeneic bone marrow (BM) transplantation. CD4(+)CD25(+) regulatory T (T(reg)) cells have recently been shown to suppress proliferative responses of CD4(+)CD25(-) T cells to alloantigenic stimulation in vitro and are required for ex vivo tolerization of donor T cells, which results in their reduced potential to induce aGVHD. Here we show that CD4(+)CD25(+) T cells isolated from the spleen or BM of donor C57BL/6 (H-2(b)) mice that have not been tolerized are still potent inhibitors of the alloresponse in vitro and of lethal aGVHD induced by C57BL/6 CD4(+)CD25(-) T cells in irradiated BALB/c (H-2(d)) hosts in vivo. The addition of…

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  National Institutes of Health