G-CSF mobilizes CD34+ regulatory monocytes that inhibit Graft-versus-Host Disease

Administration of G-CSF mobilizes a unique population of CD11b+Ly6C+CD34+mature monocytes that can inhibit GVHD in murine models of BMT via an iNOS-dependent mechanism. The transcriptional profiles of flow sorted lineage-CD11b+CD34+ cells from G-CSF treated mice were compared with conventional splenic Ly6C+ and Ly6C- monocytes, progenitor cells and cultured myeloid-derived suppressor cells. Further comparisons were made with lineage-CD11b+CD34+ cells from G-CSF treated mice that had been grown in culture or that were derived from iNOS ko mice.

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