Distribution of cells bearing receptors for a colony-stimulating factor (CSF-1) in murine tissues.
ABSTRACT CSF-1 is a subclass of the colony-stimulating factors that specifically stimulates the growth of mononuclear phagocytes. We used the binding of 125I-CSF-1 at 0 degrees C by single cell suspensions from various murine tissues, in conjunction with radioautography, to determine the frequency of binding cells, their identity, and the number of binding sites per binding cell. For all tissues examined, saturation of binding sites was achieved within 2 h at 2--3 x 10(-10) M 125I-CSF-1. The binding was irreversible and almost completely blocked by a 2 h preincubation with 5 x 10(-10) M CSF-1. 125I-CSF-1 binding was exhibited by 4.3% of bone marrow cells, 7.5% of blood mononuclear cells, 2.4% of spleen cells, 20.5% of peritoneal cells, 11.8% of pulmonary alveolar cells and 0.4% of lymph node cells. Four morphologically distinguishable cell types bound 125I-CSF-1: blast cells; mononuclear cells with a ratio of nuclear to cytoplasmic area (N/C) greater than 1; cells with indented nuclei; and mononuclear cells with N/C less than or equal to 1. No CSF-1 binding cells were detected among blood granulocytes or thymus cells. Bone marrow promyelocytes, myelocytes, neutrophilic granulocytes, eosinophilic granulocytes, nucleated erythroid cells, enucleated erythrocytes, and megakaryocytes also failed to bind. The frequency distribution of grain counts per cell for blood mononuclear cells was homogenous. In contrast, those for bone marrow, spleen, alveolar, and peritoneal cells were heterogeneous. The monocytes in blood or bone marrow (small cells, with either indented nuclei or with N/C greater than 1) were relatively uniformly labeled, possessing approximately 3,000 binding sites per cell. Larger binding cells (e.g., alveolar cells) may possess higher numbers of receptors. It is concluded that CSF-1 binding is restricted to mononuclear phagocytic cells and their precursors and that it can be used to identify both mature and immature cells of this series.
Full-textDOI: · Available from: E. Richard Stanley, Jul 02, 2015
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ABSTRACT: This unit provides protocols for measuring the abundance and growth of macrophage precursors in agar cultures and the proliferation of isolated mature macrophages in vitro, by either direct cell counting or by DNA measurement. Methods for the immunohistochemical identification of macrophages and the determination of their proliferative status in vivo by immunofluorescence are also included. It also describes methods for characterization of macrophage differentiation through the immunofluorescence analysis of cell-surface expression of CSF-1 receptor.Current protocols in immunology / edited by John E. Coligan ... [et al.] 02/2011; Chapter 14:Unit 14.20.1-26. DOI:10.1002/0471142735.im1420s92
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ABSTRACT: Uropathogenic Escherichia coli (UPEC), the causative agent of approximately 85% of urinary tract infections (UTI), is a major health concern primarily affecting women. During infection, neutrophils infiltrate the bladder, but the mechanism of recruitment is not well understood. Here, we investigated the role of UPEC-induced cytokine production in neutrophil recruitment and UTI progression. We first examined the kinetics of cytokine expression during UPEC infection of the bladder, and their contribution to neutrophil recruitment. We found that UPEC infection induces expression of several pro-inflammatory cytokines including granulocyte colony-stimulating factor (G-CSF, CSF-3), not previously known to be involved in the host response to UTI. G-CSF induces neutrophil emigration from the bone marrow; these cells are thought to be critical for bacterial clearance during infection. Upon neutralization of G-CSF during UPEC infection, we found fewer circulating neutrophils, decreased neutrophil infiltration into the bladder and, paradoxically, a decreased bacterial burden in the bladder. However, depletion of G-CSF resulted in a corresponding increase in macrophage-activating cytokines, such as monocyte chemotactic protein-1 (MCP-1, CCL-2) and Il-1beta, which may be key in host response to UPEC infection, potentially resolving the paradoxical decreased bacterial burden. Thus, G-CSF acts in a previously unrecognized role to modulate the host inflammatory response during UPEC infection.Cellular Microbiology 09/2008; 10(12):2568-78. DOI:10.1111/j.1462-5822.2008.01230.x · 4.82 Impact Factor
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ABSTRACT: Signal-transducing adaptor protein-2 (STAP-2) is a recently identified adaptor protein as a c-Fms/M-CSF receptor-interacting protein and constitutively expressed in macrophages. Our previous studies also revealed that STAP-2 binds to MyD88 and IKK-alpha/beta, and modulates NF-kappaB signaling in macrophages. In the present study, we examined physiological roles of the interaction between STAP-2 and c-Fms in Raw 264.7 macrophage cells. Our immunoprecipitation has revealed that c-Fms directly interacts with the PH domain of STAP-2 independently on M-CSF-stimulation. Ectopic expression of STAP-2 markedly suppressed M-CSF-induced tyrosine phosphorylation of c-Fms as well as activation of Akt and extracellular signal regulated kinase. In addition, Raw 264.7 cells over-expressing STAP-2 showed impaired migration in response to M-CSF and wound-healing process. Taken together, our findings demonstrate that STAP-2 directly binds to c-Fms and interferes with the PI3K signaling, which leads to macrophage motility, in Raw 264.7 cells.Biochemical and Biophysical Research Communications 08/2007; 358(3):931-7. DOI:10.1016/j.bbrc.2007.05.030 · 2.28 Impact Factor