scholarly journals Efficient osteoclast differentiation requires local complement activation

Blood ◽  
2010 ◽  
Vol 116 (22) ◽  
pp. 4456-4463 ◽  
Author(s):  
Zhidan Tu ◽  
Hong Bu ◽  
James E. Dennis ◽  
Feng Lin
Keyword(s):  
Neutralizing Antibodies ◽  
Alternative Pathway ◽  
Osteoclast Differentiation ◽  
Underlying Mechanism ◽  
Complement Components ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Blocking Antibodies ◽  
C3 Receptors ◽  
Stimulating Factor

Previous studies using blocking antibodies suggested that bone marrow (BM)–derived C3 is required for efficient osteoclast (OC) differentiation, and that C3 receptors are involved in this process. However, the detailed underlying mechanism and the possible involvement of other complement receptors remain unclear. In this report, we found that C3−/− BM cells exhibited lower RANKL/OPG expression ratios, produced smaller amounts of macrophage colony-stimulating factor and interleukin-6 (IL-6), and generated significantly fewer OCs than wild-type (WT) BM cells. During differentiation, in addition to C3, WT BM cells locally produced all other complement components required to activate C3 and to generate C3a/C5a through the alter-native pathway, which is required for efficient OC differentiation. Abrogating C3aR/C5aR activity either genetically or pharmaceutically suppressed OC generation, while stimulating WT or C3−/− BM cells with exogenous C3a and/or C5a augmented OC differentiation. Furthermore, supplementation with IL-6 rescued OC generation from C3−/− BM cells, and neutralizing antibodies to IL-6 abolished the stimulatory effects of C3a/C5a on OC differentiation. These data indicate that during OC differentiation, BM cells locally produce components, which are activated through the alternative pathway to regulate OC differentiation. In addition to C3 receptors, C3aR/C5aR also regulate OC differentiation, at least in part, by modulating local IL-6 production.

Perverted responses of the human granulocyte-macrophage colony-stimulating factor receptor in mouse cell lines due to cross-species β-subunit association

Blood ◽  
2001 ◽  
Vol 98 (10) ◽  
pp. 3165-3168 ◽  
Author(s):  
Barbara McClure ◽  
Frank Stomski ◽  
Angel Lopez ◽  
Joanna Woodcock
Keyword(s):  
Cell Lines ◽  
Underlying Mechanism ◽  
Mouse Cell ◽  
Colony Stimulating Factor ◽  
Murine Cell ◽  
Gm Csf ◽  
Murine Cell Line ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Abstract Transfected murine cell lines are commonly used to study the function of many human cytokine or receptor mutants. This study reports the inappropriate activation of the human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor by the human GM-CSF antagonist, E21R, when the human receptor is introduced into the murine cell line BaF-B03. E21R-induced proliferation of the BaF-B03 cells is dependent on transfection with both hGM-CSF receptor α and βc subunits. Studies on the underlying mechanism revealed constitutive association between human and mouse βc and GM-CSF receptor-α, tyrosine phosphorylation of mouse and human βc, and association of phosphorylated mouse βc into an activated human GM-CSF receptor complex in response to E21R and GM-CSF. This interspecies receptor cross-talk of receptor signaling subunits may produce misleading results and emphasizes the need to use cell lines devoid of the cognate endogenous receptors for functional analysis of ligand and receptor mutants.

scholarly journals The Chemotactic Cytokine Eotaxin Acts as a Granulocyte-Macrophage Colony-Stimulating Factor During Lung Inflammation

Blood ◽  
1998 ◽  
Vol 91 (6) ◽  
pp. 1909-1916 ◽  
Author(s):  
Amnon Peled ◽  
Jose Angel Gonzalo ◽  
Clare Lloyd ◽  
Jose-Carlos Gutierrez-Ramos
Keyword(s):  
Neutralizing Antibodies ◽  
Allergic Inflammation ◽  
Colony Stimulating Factor ◽  
Chemotactic Cytokine ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor ◽  
Myeloid Progenitors

Abstract During inflammatory processes, inflamed tissues signal the bone marrow (BM) to produce more mature leukocytes in ways that are not yet understood. We report here that, during the development of lung allergic inflammation, the administration of neutralizing antibodies to the chemotactic cytokine, Eotaxin, prevented the increase in the number of myeloid progenitors produced in the BM, therefore reducing the output of mature myeloid cells from BM. Conversely, the in vivo administration of Eotaxin increased the number of myeloid progenitors present in the BM. Furthermore, we found that, in vitro, Eotaxin is a colony-stimulating factor for granulocytes and macrophages. Eotaxin activity synergized with stem cell factor but not with interleukin-3 or granulocyte-macrophage colony-stimulating factor and was inhibited bypertussis toxin. We report also that CCR-3, the receptor for Eotaxin, was expressed by hematopoietic progenitors (HP). Thus, during inflammation, Eotaxin acts in a paracrine way to shift the differentiation of BM HP towards the myeloid lineage.

scholarly journals Identification of functionally distinct domains of human granulocyte- macrophage colony-stimulating factor using monoclonal antibodies

Blood ◽  
1991 ◽  
Vol 77 (5) ◽  
pp. 1033-1043 ◽  
Author(s):  
Y Kanakura ◽  
SA Cannistra ◽  
CB Brown ◽  
M Nakamura ◽  
GF Seelig ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Solid Phase ◽  
Receptor Interaction ◽  
Enzyme Linked Immunosorbent Assay ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Abstract Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a glycoprotein that is required for the survival, growth, and differentiation of hematopoietic progenitor cells. Although the primary structure of GM-CSF is known from cDNA cloning, the relationship between structure and function of GM-CSF is not fully understood. Fifteen different monoclonal antibodies (MoAbs) to human GM-CSF were generated to map immunologically distinct areas of the molecule. Each of the MoAbs was biotinylated and shown by enzyme-linked immunosorbent assay to bind to recombinant GM-CSF that had been affixed to a solid phase. Each of the 15 unconjugated MoAbs was then used to compete with each biotinylated MoAb for binding to GM-CSF. These cross-blocking studies identified eight distinct epitopes of native GM-CSF. Seven of these epitopes were also present in denatured GM-CSF by Western blotting, and four of the epitopes were at least partially conserved on GM-CSF that was reduced in beta-mercaptoethanol. MoAbs to four of eight epitopes neutralized both recombinant (glycosylated and nonglycosylated) and natural human GM-CSF in a GM colony-forming unit (CFU-GM) assay and blocked GM-CSF-induced activation of neutrophils. For most of the antibodies there was a good correlation between neutralizing activity and the capacity to block binding of 125I-GM-CSF to neutrophils or blasts. Non-neutralizing antibodies to one epitope partially blocked binding of 125I-GM-CSF to neutrophils. None of the MoAbs neutralized interleukin-3, G-CSF, or M-CSF. The locations of seven of the epitopes could be partially mapped with regard to the amino acid structure by determining reactivity to GM-CSF synthetic peptides or to human-mouse chimeric GM-CSFs. The neutralizing antibodies were found to map to amino acids 40–77, 78–94, or 110–127. Thus, these MoAbs are useful to identify functional domains of GM-CSF and in identifying regions that are likely to be involved in receptor interaction.

scholarly journals Leucocytosis and Stroke in a Lung Cancer Patient

2020 ◽  
Author(s):  
Neha Akkad ◽  
Yang Jiang ◽  
Daniel Shin
Keyword(s):  
Paraneoplastic Syndrome ◽  
Underlying Mechanism ◽  
Tumour Resection ◽  
Bone Marrow Stimulation ◽  
Interleukin 5 ◽  
Gm Csf ◽  
Underlying Malignancy ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Significant leucocytosis in the setting of an underlying malignancy may be attributed to several causes and is not uncommon; however, extreme leucocytosis (>50×109 cells/l) and hypereosinophilia is less common and may represent a paraneoplastic syndrome. The underlying mechanism is thought to be bone marrow stimulation by tumour-produced cytokines, most notably interleukin-5 (IL-5) and granulocyte-macrophage colony-stimulating factor (GM-CSF). This paraneoplastic syndrome is likely reflective of extensive disease and dissemination, and options for treatment are limited but include tumour resection, corticosteroids and hydroxyurea. In this report, we discuss an unusual case of known stage III lung adenocarcinoma presenting with an ischaemic stroke and extreme leucocytosis and hypereosinophilia. 

Local concentrations of macrophage colony-stimulating factor mediate osteoclastic differentiation

1995 ◽  
Vol 269 (6) ◽  
pp. E1024-E1030 ◽  
Author(s):  
S. L. Perkins ◽  
S. J. Kling
Keyword(s):  
Bone Marrow ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nonspecific Esterase ◽  
Colony Stimulating Factor ◽  
Murine Bone Marrow ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Macrophage colony-stimulating factor (M-CSF) is essential for differentiation of osteoclasts and macrophages from a common bone marrow precursor. Using ST-2 stromal cell/murine bone marrow coculture, we studied the effects of increasing amounts of M-CSF on differentiation of macrophages and osteoclasts. Addition of exogenous M-CSF caused a dose-dependent 98% decrease in tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells, accompanied by a 2.5-fold increase in nonspecific esterase-staining macrophages. Similar decrease in osteoclastic functional activity, including 125I-labeled calcitonin binding and calcitonin-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) production, were observed. Addition of exogenous M-CSF beyond 6 days in coculture had a decreasing ability to inhibit osteoclast formation, suggesting that M-CSF exerts its effects early in osteoclast differentiation, during the proposed proliferative phase of osteoclast formation. Similarly, early addition of neutralizing anti-M-CSF inhibited osteoclast formation, with diminishing effects beyond day 9. These results suggest that local high concentrations of M-CSF may influence the early determination of terminal differentiation into either macrophages or osteoclasts.

FLT3 ligand can substitute for macrophage colony-stimulating factor in support of osteoclast differentiation and function

Blood ◽  
2001 ◽  
Vol 98 (9) ◽  
pp. 2707-2713 ◽  
Author(s):  
Jeny Maree Lean ◽  
Karen Fuller ◽  
Timothy John Chambers
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Bone Marrow Cells ◽  
Osteoclast Differentiation ◽  
Colony Stimulating Factor ◽  
Flt3 Ligand ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor ◽  
Marrow Cells

Abstract Although bone resorption and osteoclast numbers are reduced in osteopetrotic (op/op) mice, osteoclasts are nevertheless present and functional, despite the absence of macrophage colony-stimulating factor (M-CSF). This suggests that alternative factors can partly compensate for the crucial actions of M-CSF in osteoclast induction. It was found that when nonadherent bone marrow cells were incubated in RANKL with Flt3 ligand (FL) without exogenous M-CSF, tartrate-resistance acid phosphatase (TRAP)–positive cells were formed, and bone resorption occurred. Without FL, only macrophagelike TRAP-negative cells were present. Granulocyte-macrophage CSF, stem cell factor, interleukin-3, and vascular endothelial growth factor could not similarly replace the need for M-CSF. TRAP-positive cell induction in FL was not due to synergy with M-CSF produced by the bone marrow cells themselves because FL also enabled their formation from the hemopoietic cells of op/op mice, which lack any M-CSF. FL appeared to substitute for M-CSF by supporting the differentiation of adherent cells that express mRNA for RANK and responsiveness to RANKL. To determine whether FL can account for the compensation for M-CSF deficiency that occurs in vivo, FL signaling was blockaded in op/op mice by the injection of soluble recombinant Flt3. It was found that the soluble receptor induced a substantial decrease in osteoclast number, strongly suggesting that FL is responsible for the partial compensation for M-CSF deficiency that occurs in these mice.

Engineering a monomeric variant of macrophage colony-stimulating factor (M-CSF) that antagonizes the c-FMS receptor

2017 ◽  
Vol 474 (15) ◽  
pp. 2601-2617 ◽  
Author(s):  
Yuval Zur ◽  
Lior Rosenfeld ◽  
Anna Bakhman ◽  
Stefan Ilic ◽  
Hezi Hayun ◽  
...  
Keyword(s):  
Bone Metastasis ◽  
Tyrosine Kinase ◽  
Osteoclast Differentiation ◽  
Bone Diseases ◽  
Tyrosine Kinase Receptor ◽  
Colony Stimulating Factor ◽  
Starting Point ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Enhanced activation of the signaling pathways that mediate the differentiation of mononuclear monocytes into osteoclasts is an underlying cause of several bone diseases and bone metastasis. In particular, dysregulation and overexpression of macrophage colony-stimulating factor (M-CSF) and its c-FMS tyrosine kinase receptor, proteins that are essential for osteoclast differentiation, are known to promote bone metastasis and osteoporosis, making both the ligand and its receptor attractive targets for therapeutic intervention. With this aim in mind, our starting point was the previously held concept that the potential of the M-CSFC31S mutant as a therapeutic is derived from its inability to dimerize and hence to act as an agonist. The current study showed, however, that dimerization is not abolished in M-CSFC31S and that the protein retains agonistic activity toward osteoclasts. To design an M-CSF mutant with diminished dimerization capabilities, we solved the crystal structure of the M-CSFC31S dimer complex and used structure-based energy calculations to identify the residues responsible for its dimeric form. We then used that analysis to develop M-CSFC31S,M27R, a ligand-based, high-affinity antagonist for c-FMS that retained its binding ability but prevented the ligand dimerization that leads to receptor dimerization and activation. The monomeric properties of M-CSFC31S,M27R were validated using dynamic light scattering and small-angle X-ray scattering analyses. It was shown that this mutant is a functional inhibitor of M-CSF-dependent c-FMS activation and osteoclast differentiation in vitro. Our study, therefore, provided insights into the sequence–structure–function relationships of the M-CSF/c-FMS interaction and of ligand/receptor tyrosine kinase interactions in general.

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