Journal of Leukocyte Biology 2014-10-01

G-CSF preferentially supports the generation of gut-homing Gr-1high macrophages in M-CSF-treated bone marrow cells.

Shahab Meshkibaf, Mark William Gower, Gregory A Dekaban, Sung Ouk Kim

Index: J. Leukoc. Biol. 96(4) , 549-61, (2014)

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Abstract

The G-CSF is best known for its activity in the generation and activation of neutrophils. In addition, studies on G-CSF(-/-) or G-CSFR(-/-) mice and BMC cultures suggested a role of G-CSF in macrophage generation. However, our understanding on the role of G-CSF in macrophage development is limited. Here, using in vitro BMC models, we demonstrated that G-CSF promoted the generation of Gr-1(high)/F4/80(+) macrophage-like cells in M-BMCs, likely through suppressing cell death and enhancing generation of Gr-1(high)/F4/80(+) macrophage-like cells. These Gr-1(high) macrophage-like cells produced "M2-like" cytokines and surface markers in response to LPS and IL-4/IL-13, respectively. Adoptive transfer of EGFP-expressing (EGFP(+)) M-BMCs showed a dominant, gut-homing phenotype. The small intestinal lamina propria of G-CSFR(-/-) mice also harbored significantly reduced numbers of Gr-1(high)/F4/80(+) macrophages compared with those of WT mice, but levels of Gr-1(+)/F4/80(-) neutrophil-like cells were similar between these mice. Collectively, these results suggest a novel function of G-CSF in the generation of gut-homing, M2-like macrophages. © 2014 Society for Leukocyte Biology.