Physiological neutrophilia of pregnancy is not associated with a rise in plasma granulocyte colony-stimulating factor (G-CSF)
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Female↗
Biomedical subjects
J E Layton
Publications and source records attributed to J E Layton.
Differential alterations in plasma colony-stimulating factor concentrations in meningococcaemia.
To determine whether circulating levels of any of the colony-stimulating factors (CSF) might contribute to the host response in severe sepsis, plasma concentrations of granulocyte CSF (G-CSF), granulocyte-macrophage CSF (GM-CSF), and macrophage CSF (M-CSF) were measured by immunoassays in 20 subjects with meningococcaemia, a bloodstream infection caused by Neisseria meningitidis, that has proven to be a valuable model to study the responses of other inflammatory mediators during sepsis and septic shock in humans. Plasma G-CSF concentrations were transiently elevated in most subjects during the early phase of meningococcaemia, and were higher in subjects with septic shock (mean +/- s.d. = 165 +/- 142 ng/ml, n = 9) compared with those who remained normotensive (mean +/- s.d. = 7 +/- 2 ng/ml, n = 10) (P < 0.05). Peak plasma G-CSF concentrations > 10 ng/ml were associated with the development of septic shock (P < 0.01), disseminated intravascular coagulation (P < 0.01), fulminant infection (P < 0.05), and a fatal outcome (P < 0.01). Plasma GM-CSF concentrations > 1 ng/ml were briefly present in subjects with life-threatening septic shock (1-15 ng/ml, n = 5), and were strongly associated with fulminant meningococcaemia (P < 0.01). Plasma M-CSF concentrations were marginally elevated in all subjects, but were not associated with complications related to or arising from sepsis-induced organ injury. This study demonstrates that plasma levels of G-CSF, GM-CSF and M-CSF show very different responses during meningococcaemia, changes which presumably reflect the different roles played by these mediators in sepsis and, potentially, in septic shock.
Adolescent↗
Tyrosine kinase JAK1 is associated with the granulocyte-colony-stimulating factor receptor and both become tyrosine-phosphorylated after receptor activation.
Granulocyte-colony-stimulating factor (G-CSF) stimulates the proliferation and differentiation of cells of the neutrophil lineage by interaction with a specific receptor. Early signal transduction events following G-CSF receptor activation were studied. We detected tyrosine phosphorylation of both the G-CSF receptor and the protein tyrosine kinase JAK1 following G-CSF binding to the human G-CSF receptor. In vitro, the kinase activity of JAK1 was increased by G-CSF stimulation. Coimmunoprecipitation of JAK1 with the G-CSF receptor suggested a physical association which existed prior to G-CSF stimulation.
Animals↗
Cytomegalovirus infection of vascular endothelial cells alters production of GM-CSF and G-CSF.
Infection of human umbilical vein endothelial cells with the clinical isolate of human cytomegalovirus (HCMV; at a multiplicity of infection of 2) severely suppresses the production of granulocyte-CSF and granulocyte-macrophage-CSF at late stages of infection (6 days post infection onwards). The effect was produced by actively multiplying virus which indicates that HCMV antigen expression is important for this suppression. The suppression in the production of these two cytokines was not due to their accumulation inside the cell nor to cell damage or lysis after infection.
Cells, Cultured↗
Endogenous haemopoietic growth factors in neutropenia and infection.
Haemopoietic growth factors (HGFs) are being administered to patients with neutropenic fever; however, little is known about the endogenous HGF response in these patients. Specific assays were used to study four HGFs, granulocyte (G-) CSF, granulocyte-macrophage (GM-) CSF, macrophage (M-) CSF and interleukin (IL-) 6 levels in the blood of patients with neutropenic fever (46 episodes). For comparison, levels were also measured in three control populations: normals (20), afebrile neutropenic (14), and bacteraemic but not neutropenic patients (20). In febrile patients, levels of G-CSF (median, range) (0.46, < 0.10-142 ng/ml). IL-6 (0.054, 0.005-24.3 ng/ml) and M-CSF (18.5, 9.9-79.1 ng/ml) were elevated compared with afebrile subjects (< 0.10, < 0.10-1.62 ng/ml). (0.008, 0.002-0.024 ng/ml) and (6.45, < 5.0-31.3 ng/ml) respectively. GM-CSF was not elevated (< 0.02, < 0.02-8.0 ng/ml) compared with afebrile subjects (0.021, < 0.02-0.20 ng/ml). Variables significantly associated (P < 0.05) with elevated cytokine levels were determined by multiple regression analyses. Factors associated with G-CSF elevation were fever, neutropenia, pathogen type and raised bilirubin and creatinine. In contrast, neutropenia was not associated with IL-6 elevation although there was an association between IL-6 elevation and fever, Gram-negative and fungal infections and raised creatinine and bilirubin. M-CSF elevation was associated with fever, renal impairment and known pathogen. Elevated G-CSF and IL-6 levels normalized rapidly (hours-days) with the resolution of infection, whereas M-CSF concentrations remained elevated for up to 10 d. Cytokine levels remained elevated in septic neutropenic patients who did not recover. In summary, G-CSF, IL-6 and M-CSF levels were significantly elevated in sepsis. In contrast, GM-CSF levels were not elevated. These studies should assist the development of therapeutic strategies using HGFs in the treatment of sepsis.
Adolescent↗
Neutralizing and nonneutralizing monoclonal antibodies to the human granulocyte-macrophage colony-stimulating factor receptor alpha-chain.
A panel of monoclonal antibodies was raised against the low-affinity human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor alpha-chain expressed as recombinant protein on murine FDC-P1 cells. All the selected antibodies were of the IgG2A isotype and bound to protein A. They each recognized both native and recombinant receptors by indirect surface immunofluorescence and by immunoprecipitation. Several of the antibodies also recognized presumably denatured receptors as detected by immunoblotting of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Three different epitopes on the extracellular domain of the GM-CSF receptor alpha-chain were defined by these antibodies, and two of the epitopes did not appear to be involved in binding hGM-CSF or in interactions with the beta-chain of the GM-CSF receptor that are required for high-affinity binding of GM-CSF. On the other hand, the epitope recognized by antibody 2B7-17-A appeared to be critically involved in the binding of GM-CSF because this antibody completely abrogated both high- and low-affinity binding of GM-CSF to native and recombinant receptors. Antibody 2B7-17-A had a relatively high affinity for the GM-CSF receptor alpha-chain (kd = 3 nmol/L) and slow dissociation kinetics (kd = 0.002 min-1). These properties made the 2B7-17-A antibody a potent inhibitor of hGM-CSF biologic action in several different bioassays, with a half-maximal inhibitory dose of about 6 nmol/L (1 microgram/mL). This antibody could prove useful in alleviating any pathologic states mediated by excess GM-CSF levels and in defining the domains of the GM-CSF receptor required for ligand binding.
Animals↗
Contrasting effects of interleukin-4 on colony-stimulating factor and interleukin-6 synthesis by vascular endothelial cells.
Endothelial cells (EC) may regulate both local and systemic aspects of inflammation through the synthesis of cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), and interleukin-6 (IL-6). EC are known to synthesize these cytokines in response to interleukin-1 (IL-1 alpha), tumor necrosis factor-alpha (TNF-alpha) and lipopolysaccharide (LPS). In this paper, we illustrate the effect of interleukin-4 (IL-4) in reducing the synthesis of GM-CSF by EC stimulated with IL-1 alpha, TNF-alpha, or LPS. This is compared with the previously reported strong synergy between IL-4 and IL-1 alpha, TNF-alpha, or LPS in the synthesis of IL-6 by EC. No clear effect of IL-4 was seen in the synthesis of G-CSF or M-CSF. The range of concentrations of IL-4 at which these effects were seen was identical for both reduced GM-CSF synthesis and increased IL-6 synthesis. The effect of IL-4 on IL-6 synthesis was seen by 4 h of treatment, while that on GM-CSF was apparent between 4 and 8 h. It is suggested that these contrasting effects of IL-4 may reflect a biological role for this cytokine in the regulation of leukocytosis and the acute phase response.
Acute-Phase Reaction↗
Human arterial smooth muscle cells synthesize granulocyte colony-stimulating factor in response to interleukin-1 alpha and tumor necrosis factor-alpha.
Vascular smooth muscle cells (SMC) are a major cell type comprising the walls of blood vessels. We report the synthesis of granulocyte colony-stimulating factor (G-CSF) by cultured human SMC obtained from the internal mammary artery and thoracic aorta. Interleukin-1 alpha (IL-1 alpha) greatly increased in a dose-dependent manner the amount of this cytokine produced by the SMC, with tumor necrosis factor-alpha (TNF-alpha) being less effective. Newly formed G-CSF could be detected in culture supernatants within 6 hours after IL-1 alpha or TNF-alpha treatment. Northern blot analysis of SMC stimulated with IL-1 alpha and TNF-alpha showed an increase in the amount of mRNA for G-CSF as compared with control cells. Enhanced G-CSF mRNA levels were observed when SMC were treated with cycloheximide in the absence or presence of added cytokine. In vasculitis, the walls of blood vessels become inflamed as evidenced by a leucocytic infiltrate usually dominated by polymorphonuclear neutrophil leukocytes (PMNs). G-CSF is known to stimulate PMNs, and our findings raise the possibility that G-CSF made by SMC contributes to the development of vasculitis lesions.
Aorta↗
Cytokine regulation of colony-stimulating factor (CSF) production in cultured human synovial fibroblasts. II. Similarities and differences in the control of interleukin-1 induction of granulocyte-macrophage CSF and granulocyte-CSF production.
Synovial fibroblasts are likely to be a significant source of granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF), which could be crucial to the pathogenesis of rheumatoid arthritis. Using specific enzyme-linked immunosorbent assays (ELISAs) and Northern analysis, GM-CSF and G-CSF expression were followed in human synovial fibroblast-like cells in response to a number of agents, either alone or in the presence of an optimal stimulatory concentration of interleukin-1 (IL-1). For both CSFs, interferon-gamma (100 U/mL) did not increase their levels but dramatically suppressed the stimulatory action of IL-1, while basic fibroblast growth factor (10(-8) mol/L), although nonstimulatory by itself, potentiated IL-1 action. The glucocorticoid, dexamethasone (10(-7) mol/L), inhibited IL-1-stimulated CSF production. However, evidence was obtained for noncoordinated CSF regulation. Cyclooxygenase inhibitors potentiated the action of IL-1 on GM-CSF synthesis but suppressed G-CSF synthesis, suggesting that endogenous cyclooxygenase products can have opposite effects in modulating the levels of each CSF. Also, the lymphokine, IL-4 (250 pmol/L), slightly inhibited GM-CSF formation in the presence of IL-1 but elevated the G-CSF levels in these cultures without having an effect by itself. Transforming growth factor beta (less than or equal to 20 ng/mL) did not modulate levels of either CSF. Mesenchymal cell production of both GM-CSF and G-CSF is generally viewed as being under coordinate control; our findings suggest that their synthesis in IL-1-stimulated human synoviocytes can be modulated by a number of agents, in some cases with divergent actions depending on which CSF is examined.
Cells, Cultured↗
Granulocyte colony-stimulating factor: structure, function and physiology.
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Amino Acid Sequence↗
Interleukin-4 suppresses granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor levels in stimulated human monocytes.
Granulocyte colony-stimulating factor (G-CSF) was quantitated in the supernatants of lipopolysaccharide (LPS)-treated human monocytes by ELISA. Unlike previous reports, the lymphokines, interleukin-4 (IL-4) and interferon-gamma (IFN-gamma), were unable to induce the synthesis of G-CSF. Both IL-4 (> or = 10 pM) and the glucocorticoid, dexamethasone (10(-7) M), inhibited G-CSF production in the LPS-treated monocytes; in contrast, IFN-gamma had a weak potentiating effect on the LPS action. Changes in antigen expression were manifested at the level of messenger RNA (mRNA). Granulocyte-macrophage (GM)-CSF in the LPS-treated monocyte supernatants was also quantitated by ELISA but its levels were somewhat lower than for G-CSF; IL-4, dexamethasone and IFN-gamma had similar effects on GM-CSF levels as on G-CSF levels. The suppression of CSF production in the stimulated monocytes by IL-4 and glucocorticoid extends the list of monocyte cytokines whose levels can be down-regulated by these agents and suggests another potential anti-inflammatory and immunosuppressive function for IL-4.
Cells, Cultured↗
Identification of a functional domain of human granulocyte colony-stimulating factor using neutralizing monoclonal antibodies.
Human granulocyte colony-stimulating factor (G-CSF) is a hemopoietic growth factor that is being used successfully to treat various forms of neutropenia. To define functionally important regions of G-CSF, we have prepared 37 monoclonal anti-G-CSF antibodies and mapped the regions of G-CSF recognized by different antibody groups. Antibodies recognizing similar epitopes were identified by competition assays, neutralization assays, conformation dependence and cross-reactivity with canine G-CSF. Seven of eight neutralizing antibodies fell into two related epitope groups and were conformation-dependent. The eighth was unrelated and conformation-independent. Peptides of G-CSF were generated by chemical or enzymatic digestion and tested for antibody reactivity. One of the neutralizing antibodies (LMM351) recognized a small, disulfide-bonded peptide from the V8 protease digest (residues 34-46). A synthetic peptide (residues 20-58) was recognized by all the neutralizing antibodies, implicating this disulfide-bonded loop in receptor binding. The epitopes recognized by nonneutralizing antibodies were found throughout G-CSF. Thus, regions of G-CSF that are not involved in receptor binding have also been defined. A CNBr peptide (residues 1-121) had greatly reduced biological activity, indicating that the COOH terminus is required for receptor binding. We predict that residues 20-46 and the COOH terminus bind to the G-CSF receptor.
Amino Acid Sequence↗
Human articular cartilage and chondrocytes produce hemopoietic colony-stimulating factors in culture in response to IL-1.
The hemopoietic CSF, granulocyte-macrophage CSF (GM-CSF) and granulocyte CSF (G-CSF), are cytokines that mediate the clonal proliferation and differentiation of progenitor cells into mature macrophages and/or granulocytes. We have employed an all-human cell culture system, specific ELISA for GM-CSF and G-CSF, and Northern analysis to investigate whether chondrocytes are a potential source of CSF in rheumatoid disease. We report that human rIL-1 stimulated in a dose-dependent manner the production of GM-CSF and G-CSF by human articular cartilage and chondrocyte monolayers in organ and cell culture, respectively. Increased levels of the CSF Ag were detected after 2 to 8 h stimulation with IL-1, and the optimum dose of IL-1 was 10 to 100 U/ml (0.06 to 0.6 nM IL-1 alpha; 0.02 to 0.2 nM IL-1 beta); neither CSF was detectable in nonstimulated cultures nor in IL-1-stimulated cultures treated with actinomycin D or cycloheximide, indicating the requirement for de novo RNA and protein synthesis. The IL-1-mediated increase in GM-CSF could also be inhibited by the corticosteroid, dexamethasone, but not by the cyclo-oxygenase inhibitor, indomethacin. Although having little effect when tested alone, TNF-alpha and lymphotoxin (TNF-beta) could synergize with IL-1 for the production of GM-CSF. Basic fibroblast growth factor, platelet-derived growth factor, and IFN-alpha and IFN-gamma each had no effect on GM-CSF levels. Results obtained by Northern analysis of chondrocyte total RNA reflected those found for the CSF Ag, namely that CSF mRNA levels were elevated in response to IL-1, but not TNF, and that there was synergy between these two cytokines. We propose that chondrocyte CSF production in response to IL-1, and the concurrent destruction of cartilage by IL-1, could provide a mechanism for the chronic nature of rheumatoid disease.
Cartilage↗
Chronic neutropenia. A new canine model induced by human granulocyte colony-stimulating factor.
Normal dogs were treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF) at 10 micrograms/kg/day for 30 d, which caused an initial neutrophilia, followed by a prolonged period of chronic neutropenia. A control dog treated with recombinant canine G-CSF (rcG-CSF) showed persistent neutrophilia over 3 mo. Serum from dogs during neutropenia contained an antibody to rhG-CSF, which neutralized the stimulatory effects of both rhG-CSF and rcG-CSF on dog marrow neutrophilic progenitor cell growth and on NFS-60 cell proliferation. 4 mo after discontinuation of rhG-CSF, the dogs' neutrophil counts returned to the normal range. Rechallenge with the rhG-CSF re-induced severe neutropenia in 1 wk. Neutropenia was transferred by plasma infusion from a neutropenic dog to a previously normal dog. These data suggest that human rhG-CSF immunizes normal dogs and thereby induces neutralization of endogenous canine G-CSF and neutropenia. This model system should allow more precise definition of the in vivo role of G-CSF.
Animals↗
Cytokine regulation of colony-stimulating factor production in cultured human synovial fibroblasts: I. Induction of GM-CSF and G-CSF production by interleukin-1 and tumor necrosis factor.
The cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF), induce a dose-dependent production of both granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte CSF (G-CSF) in cultured human synovial cells, as measured by immunoassay. With IL-1, significant levels of both CSFs were first detected within 6 to 12 hours, with a maximum reached 24 to 48 hours after commencement of stimulation. A synergistic effect was detected between IL-1 and TNF in production of both CSFs in these cells. No evidence was obtained for the IL-1-induced effect to be mediated by induction of endogenous TNF nor for the TNF-induced stimulation to involve IL-1. IL-1-stimulated synovial cells were shown to secrete biologically active GM-CSF and G-CSF, which were specifically inhibited by their respective monoclonal antibodies. The transcription inhibitor, actinomycin D, and protein synthesis inhibitor, cycloheximide, inhibited the increase in GM-CSF and G-CSF production induced by IL-1 and TNF. Finally, other cytokines, IL-3, interferon gamma (IFN gamma), IL-2, platelet-derived growth factor (PDGF), epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha), failed to stimulate either GM-CSF or G-CSF production, whether alone or in the presence of IL-1. These results suggest that cytokine-stimulated synovial fibroblasts may be a major source of intraarticular CSF production in the joints of patients with inflammatory arthritis; as a result, monocyte/macrophages and granulocytes may be activated, leading to perpetuation of the inflammation and destructive events occurring in these lesions.
Cells, Cultured↗
Monoclonal antibodies that recognize human granulocyte-macrophage colony-stimulating factor and neutralize its bioactivity in vitro.
We have produced monoclonal antibodies to bacterially synthesized, human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and have studied in detail the characteristics of three strongly neutralizing antibodies. The antibodies reacted with GM-CSF at high dilution (EC50 = 0.1-1.7 nM) in an indirect ELISA but did not react with murine GM-CSF or other cytokines. They also recognized glycosylated hGM-CSF produced by human lymphocytes. The antibodies were able to immunoprecipitate rhGM-CSF, but only reacted weakly with rhGM-CSF on Western blots, indicating that they recognized a conformation-dependent epitope. Cross-blocking studies showed that the three antibodies recognized overlapping epitopes. The antibodies inhibited binding of 125I-labeled rhGM-CSF to HL-60 cells at nanomolar concentrations and neutralized GM-CSF activity in two different bioassays. These antibodies thus provide a useful tool for analyzing the specificity of bioassays and for further studies of the production and function of GM-CSF in vitro and in vivo.
Animals↗
Cloned stromal cell lines derived from human Whitlock/Witte-type long-term bone marrow cultures.
We report a human bone marrow culture technique that initially parallels the murine Whitlock/Witte culture system. As in the murine system, B cells predominate over other cell types, and all differentiation stages from pre-B to plasma cell are observed. Although these human long-term cultures pass through stages resembling phases I to III of murine Whitlock/Witte cultures, no outgrowth of nonadherent cells was seen after cultures had reached the "crisis" phase unless Epstein-Barr virus (EBV)-transformants appeared. The stromal cells persisted well beyond crisis, but they could not be maintained and passaged as cell lines, limiting their use in molecular analysis. Transfection of these stromal cells with plasmid DNA containing the simian virus 40 (SV40) early region yielded 124 cloned cell lines. Analysis of these lines showed that all expressed SV40 large T antigen, but they retained most phenotypic markers found on non-transformed stromal cells. When adherent and T-cell-depleted bone marrow cells were cultured on either nontransformed stromal layers or transformed cell lines they proliferated actively and soon yielded predominantly lymphoid nonadherent populations. Moreover, prolonged survival of acute lymphoblastic leukemia cells of pre-B phenotype was regularly achieved on both normal and transformed adherent cell layers. Although the liquid culture system favored lymphocytes, transformed stroma supported colony formation by both human and murine hemopoietic progenitors when marrow was added in agar medium. This was not explained by colony-stimulating factor (CSF) production, because striking heterogeneity in the levels of granulocyte CSF (G-CSF) and granulocyte-macrophage CSF (GM-CSF) secretion by the lines was noted. Some lines that did not produce detectable CSF demonstrated good support of fresh bone marrow growth and acute lymphoblastic leukemia (ALL) cell survival. The heterogeneity of these cell lines and their capacity to support hemopoiesis suggest that they will be useful in studying the molecular basis of in vitro lymphohemopoiesis in man.
Age Factors↗
Granulocyte colony-stimulating factor and neutrophil recovery after high-dose chemotherapy and autologous bone marrow transplantation.
Granulocyte colony-stimulating factor (G-CSF) was administered by continuous subcutaneous infusion to 15 patients with non-myeloid malignancies treated by high-dose chemotherapy and autologous bone marrow infusion. G-CSF was given at variable dosage based on neutrophil count. Sustained serum levels of G-CSF were achieved. Neutrophil recovery was accelerated in G-CSF treated patients compared with 18 historical controls and exceeded 0.5 x 10(9)/l at a mean of 11 days after marrow infusion compared with 20 days for controls, a significant difference. This reduction led to significantly fewer days of parenteral antibiotic therapy, 11 versus 18 days in controls, and less isolation in reverse-barrier nursing, 10 versus 18 days.
Agranulocytosis↗