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Enforced granulocyte/macrophage colony-stimulating factor signals do not support lymphopoiesis, but instruct lymphoid to myelomonocytic lineage conversion.

Iwasaki-Arai J, Iwasaki H, Miyamoto T, Watanabe S, Akashi K - J. Exp. Med. (2003)

Bottom Line: We evaluated the effects of ectopic granulocyte/macrophage colony-stimulating factor (GM-CSF) signals on hematopoietic commitment and differentiation.Strikingly, >50% hGM-CSFR+ common lymphoid progenitors (CLPs) and >20% hGM-CSFR+ pro-T cells gave rise to granulocyte, monocyte, and/or myeloid dendritic cells, but not MegE lineage cells in the presence of hGM-CSF.Thus, hGM-CSF transduces permissive signals for myeloerythroid differentiation, whereas it transmits potent instructive signals for the GM differentiation to CLPs and early T cell progenitors.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.

ABSTRACT
We evaluated the effects of ectopic granulocyte/macrophage colony-stimulating factor (GM-CSF) signals on hematopoietic commitment and differentiation. Lineage-restricted progenitors purified from mice with the ubiquitous transgenic human GM-CSF receptor (hGM-CSFR) were used for the analysis. In cultures with hGM-CSF alone, hGM-CSFR-expressing (hGM-CSFR+) granulocyte/monocyte progenitors (GMPs) and megakaryocyte/erythrocyte progenitors (MEPs) exclusively gave rise to granulocyte/monocyte (GM) and megakaryocyte/erythroid (MegE) colonies, respectively, providing formal proof that GM-CSF signals support the GM and MegE lineage differentiation without affecting the physiological myeloid fate. hGM-CSFR transgenic mice were crossed with mice deficient in interleukin (IL)-7, an essential cytokine for T and B cell development. Administration of hGM-CSF in these mice could not restore T or B lymphopoiesis, indicating that enforced GM-CSF signals cannot substitute for IL-7 to promote lymphopoiesis. Strikingly, >50% hGM-CSFR+ common lymphoid progenitors (CLPs) and >20% hGM-CSFR+ pro-T cells gave rise to granulocyte, monocyte, and/or myeloid dendritic cells, but not MegE lineage cells in the presence of hGM-CSF. Injection of hGM-CSF into mice transplanted with hGM-CSFR+ CLPs blocked their lymphoid differentiation, but induced development of GM cells in vivo. Thus, hGM-CSF transduces permissive signals for myeloerythroid differentiation, whereas it transmits potent instructive signals for the GM differentiation to CLPs and early T cell progenitors. These data suggest that a majority of CLPs and a fraction of pro-T cells possess plasticity for myelomonocytic differentiation that can be activated by ectopic GM-CSF signals, supporting the hypothesis that the down-regulation of GM-CSFR is a critical event in producing cells with a lymphoid-restricted lineage potential.

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hGM-CSF signals cannot support pro-B cell differentiation but stimulate large granular lymphocytes with NK phenotype. (A) B220+ CD43+ IgM− pro-B cell fraction was cultured on an S17 stromal layer for 14 d, after which IL-7R+/+ hGM-CSFR+ pro-B cells gave rise to CD19+ IgM+ mature B cells in the absence of additional cytokines. IL-7R−/− hGM-CSFR+ pro-B fraction gave rise to CD19− B220+ NK1.1+ CD3− NK cells, but not mature B cells in the presence of hGM-CSF. (B) Morphology of CD19− B220+ NK1.1+ CD3− NK cells. These cells possess coarse cytoplasmic granules, which are specific to large granular lymphocytes.
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fig4: hGM-CSF signals cannot support pro-B cell differentiation but stimulate large granular lymphocytes with NK phenotype. (A) B220+ CD43+ IgM− pro-B cell fraction was cultured on an S17 stromal layer for 14 d, after which IL-7R+/+ hGM-CSFR+ pro-B cells gave rise to CD19+ IgM+ mature B cells in the absence of additional cytokines. IL-7R−/− hGM-CSFR+ pro-B fraction gave rise to CD19− B220+ NK1.1+ CD3− NK cells, but not mature B cells in the presence of hGM-CSF. (B) Morphology of CD19− B220+ NK1.1+ CD3− NK cells. These cells possess coarse cytoplasmic granules, which are specific to large granular lymphocytes.

Mentions: IL-7−/− mice displayed a differentiation block at the transition from the pro-B to pre-B stage. The impaired differentiation was not restored by the hGM-CSF injection (Fig. 3 B). Next, we purified IL-7Rα−/− hGM-CSFR+ and IL-7Rα+/+ hGM-CSFR+ B220+ CD43+ IgM− pro-B cells, and tested their differentiation on an S17 stromal layer (Fig. 4) . IL-7Rα+/+ hGM-CSFR+ pro-B cells differentiated into mature CD19+ IgM+ B cells in the absence of cytokines. The addition of 20 ng/ml hGM-CSF in the culture resulted in an unexpected expansion of CD19− B220+ CD3− NK1.1+ LGL (Fig. 4 B), which also expressed Mac-1 at a low level (not depicted). IL-7Rα−/− hGM-CSFR+ pro-B cells did not mature into B cells in vitro in the presence of hGM-CSF, indicating that GM-CSF signals cannot substitute for the nonredundant IL-7 in B lymphopoiesis. Instead, IL-7Rα−/− hGM-CSFR+ pro-B cells only gave rise to morphologically mature LGL cells in the presence of hGM-CSF. Thus, enforced hGM-CSF signals cannot substitute for IL-7 signals in T and B cell development but can stimulate proliferation of an NK-LGL subset. The NK-LGL population was phenotypically identical to the minor CD19− B220+ CD3-NK1.1+ population that is reportedly included in the B220+ CD43+ IgM− pro-B fraction (39). This is consistent with a report by Nishijima et al. (36), in which in vivo injection of a high dose of hGM-CSF into hGM-CSFR transgenic mice resulted in an expansion of Mac-1+ NK1.1+ NK-LGL cells.


Enforced granulocyte/macrophage colony-stimulating factor signals do not support lymphopoiesis, but instruct lymphoid to myelomonocytic lineage conversion.

Iwasaki-Arai J, Iwasaki H, Miyamoto T, Watanabe S, Akashi K - J. Exp. Med. (2003)

hGM-CSF signals cannot support pro-B cell differentiation but stimulate large granular lymphocytes with NK phenotype. (A) B220+ CD43+ IgM− pro-B cell fraction was cultured on an S17 stromal layer for 14 d, after which IL-7R+/+ hGM-CSFR+ pro-B cells gave rise to CD19+ IgM+ mature B cells in the absence of additional cytokines. IL-7R−/− hGM-CSFR+ pro-B fraction gave rise to CD19− B220+ NK1.1+ CD3− NK cells, but not mature B cells in the presence of hGM-CSF. (B) Morphology of CD19− B220+ NK1.1+ CD3− NK cells. These cells possess coarse cytoplasmic granules, which are specific to large granular lymphocytes.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2193786&req=5

fig4: hGM-CSF signals cannot support pro-B cell differentiation but stimulate large granular lymphocytes with NK phenotype. (A) B220+ CD43+ IgM− pro-B cell fraction was cultured on an S17 stromal layer for 14 d, after which IL-7R+/+ hGM-CSFR+ pro-B cells gave rise to CD19+ IgM+ mature B cells in the absence of additional cytokines. IL-7R−/− hGM-CSFR+ pro-B fraction gave rise to CD19− B220+ NK1.1+ CD3− NK cells, but not mature B cells in the presence of hGM-CSF. (B) Morphology of CD19− B220+ NK1.1+ CD3− NK cells. These cells possess coarse cytoplasmic granules, which are specific to large granular lymphocytes.
Mentions: IL-7−/− mice displayed a differentiation block at the transition from the pro-B to pre-B stage. The impaired differentiation was not restored by the hGM-CSF injection (Fig. 3 B). Next, we purified IL-7Rα−/− hGM-CSFR+ and IL-7Rα+/+ hGM-CSFR+ B220+ CD43+ IgM− pro-B cells, and tested their differentiation on an S17 stromal layer (Fig. 4) . IL-7Rα+/+ hGM-CSFR+ pro-B cells differentiated into mature CD19+ IgM+ B cells in the absence of cytokines. The addition of 20 ng/ml hGM-CSF in the culture resulted in an unexpected expansion of CD19− B220+ CD3− NK1.1+ LGL (Fig. 4 B), which also expressed Mac-1 at a low level (not depicted). IL-7Rα−/− hGM-CSFR+ pro-B cells did not mature into B cells in vitro in the presence of hGM-CSF, indicating that GM-CSF signals cannot substitute for the nonredundant IL-7 in B lymphopoiesis. Instead, IL-7Rα−/− hGM-CSFR+ pro-B cells only gave rise to morphologically mature LGL cells in the presence of hGM-CSF. Thus, enforced hGM-CSF signals cannot substitute for IL-7 signals in T and B cell development but can stimulate proliferation of an NK-LGL subset. The NK-LGL population was phenotypically identical to the minor CD19− B220+ CD3-NK1.1+ population that is reportedly included in the B220+ CD43+ IgM− pro-B fraction (39). This is consistent with a report by Nishijima et al. (36), in which in vivo injection of a high dose of hGM-CSF into hGM-CSFR transgenic mice resulted in an expansion of Mac-1+ NK1.1+ NK-LGL cells.

Bottom Line: We evaluated the effects of ectopic granulocyte/macrophage colony-stimulating factor (GM-CSF) signals on hematopoietic commitment and differentiation.Strikingly, >50% hGM-CSFR+ common lymphoid progenitors (CLPs) and >20% hGM-CSFR+ pro-T cells gave rise to granulocyte, monocyte, and/or myeloid dendritic cells, but not MegE lineage cells in the presence of hGM-CSF.Thus, hGM-CSF transduces permissive signals for myeloerythroid differentiation, whereas it transmits potent instructive signals for the GM differentiation to CLPs and early T cell progenitors.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.

ABSTRACT
We evaluated the effects of ectopic granulocyte/macrophage colony-stimulating factor (GM-CSF) signals on hematopoietic commitment and differentiation. Lineage-restricted progenitors purified from mice with the ubiquitous transgenic human GM-CSF receptor (hGM-CSFR) were used for the analysis. In cultures with hGM-CSF alone, hGM-CSFR-expressing (hGM-CSFR+) granulocyte/monocyte progenitors (GMPs) and megakaryocyte/erythrocyte progenitors (MEPs) exclusively gave rise to granulocyte/monocyte (GM) and megakaryocyte/erythroid (MegE) colonies, respectively, providing formal proof that GM-CSF signals support the GM and MegE lineage differentiation without affecting the physiological myeloid fate. hGM-CSFR transgenic mice were crossed with mice deficient in interleukin (IL)-7, an essential cytokine for T and B cell development. Administration of hGM-CSF in these mice could not restore T or B lymphopoiesis, indicating that enforced GM-CSF signals cannot substitute for IL-7 to promote lymphopoiesis. Strikingly, >50% hGM-CSFR+ common lymphoid progenitors (CLPs) and >20% hGM-CSFR+ pro-T cells gave rise to granulocyte, monocyte, and/or myeloid dendritic cells, but not MegE lineage cells in the presence of hGM-CSF. Injection of hGM-CSF into mice transplanted with hGM-CSFR+ CLPs blocked their lymphoid differentiation, but induced development of GM cells in vivo. Thus, hGM-CSF transduces permissive signals for myeloerythroid differentiation, whereas it transmits potent instructive signals for the GM differentiation to CLPs and early T cell progenitors. These data suggest that a majority of CLPs and a fraction of pro-T cells possess plasticity for myelomonocytic differentiation that can be activated by ectopic GM-CSF signals, supporting the hypothesis that the down-regulation of GM-CSFR is a critical event in producing cells with a lymphoid-restricted lineage potential.

Show MeSH
Related in: MedlinePlus