Regular Article TRANSPLANTATION Absence of STAT1 in donor-derived plasmacytoid dendritic cells

GVHD induced by delayed donor lymphocyte infusion via the expansion of CD92Siglec Hhi pDCs, which are low producers of IFNa and IL-12. pDCs recovered from STAT12/2 BM chimeras show increased expression of S100A8, S100A9, and STAT3. Selective targetingofnon-Tcells, includingantigen-presentingcells (APCs), isapotential strategy to prevent graft-versus-host-disease (GVHD) but tomaintain graft-versus-tumor (GVT) effects. Because type I and II interferons signal through signal transducer and activator of transcription-1 (STAT1), and contribute to activation of APCs after allogeneic bonemarrow transplant (alloBMT), we examined whether the absence of STAT1 in donor APCs could prevent GVHD while preserving immune competence. Transplantation o