scholarly journals Tofacitinib Reprograms Human Monocytes of IBD Patients and Healthy Controls Toward a More Regulatory Phenotype

2019 ◽  
Vol 26 (3) ◽  
pp. 391-406 ◽  
Author(s):  
Friederike Cordes ◽  
Eva Lenker ◽  
Lea J Spille ◽  
Toni Weinhage ◽  
Dominik Bettenworth ◽  
...  
Keyword(s):  
Cellular Response ◽  
Inflammatory Responses ◽  
Healthy Controls ◽  
Regulatory Pathways ◽  
Gm Csf ◽  
Bowel Diseases ◽  
Activated Monocytes ◽  
Macrophage Colony ◽  
The Impact ◽  
Regulatory Phenotype

Abstract Background The inhibition of Janus kinases (JAKs) and subsequent signal transducers and activators of transcription (STATs) by tofacitinib represents a new therapeutic strategy in inflammatory bowel diseases (IBD) as clinical trials have led to approval of tofacitinib for ulcerative colitis (UC) and hint at a possible efficacy for Crohn`s disease (CD). However, the impact of tofacitinib on cellular response of monocytes, which are key players in inflammatory responses, has not been investigated so far. We aimed to analyze JAK/STAT-inhibition by tofacitinib in monocytes of IBD patients and healthy controls. Methods Primary monocytes of IBD patients with active disease and healthy controls (n = 18) were analyzed for cytokine expression and phenotype after granulocyte macrophage colony-stimulating factor (GM-CSF)/interferon (IFN)γ-stimulation and tofacitinib pretreatment (1–1000 nM) and capacity to induce Foxp3+-regulatory T cells (Tregs) in cocultures. In total, 20 UC patients and 21 CD patients were included. Additionally, dose-dependent inhibition of JAK/STAT-phosphorylation was analyzed in controls. Results Pro-inflammatory costimulation with GM-CSF/IFNγ resulted in significant tumor necrosis factor (TNFα) and interleukin (IL)-6 increase, whereas IL-10 expression decreased in monocytes. Tofacitinib modulated the responses of activated monocytes toward a regulatory phenotype through reduced TNFα and IL-6 secretion and enhanced Treg induction in cocultures. However, in monocytes from active IBD patients, higher tofacitinib dosages were needed for blockade of pro-inflammatory cytokines. Tofacitinib induced stronger regulatory phenotypes in monocytes of UC patients, including more effective inhibition of pro-inflammatory pathways and better restoration of anti-inflammatory mechanisms as compared with CD-derived monocytes. Conclusion Tofacitinib dose-dependently reprograms monocytes toward a more regulatory cell type. This beneficial effect possibly results from selective JAK/STAT-blockade by adequate tofacitinib dosage with inhibition of pro-inflammatory responses and permission of a balance-shift toward regulatory pathways.

scholarly journals Expression of the macrophage-specific colony-stimulating factor in human monocytes treated with granulocyte-macrophage colony-stimulating factor

Blood ◽  
1987 ◽  
Vol 69 (4) ◽  
pp. 1259-1261
Author(s):  
J Horiguchi ◽  
MK Warren ◽  
D Kufe
Keyword(s):  
T Cells ◽  
Gene Product ◽  
Phorbol Ester ◽  
Human Monocytes ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Activated Monocytes ◽  
Macrophage Colony ◽  
Stimulating Factor

The macrophage-specific colony-stimulating factor (CSF-1, M-CSF) regulates the survival, growth and differentiation of monocytes. We have recently demonstrated that phorbol ester induces expression of CSF- 1 in human monocytes. These findings suggested that activated monocytes are capable of producing their own lineage-specific CSF. The present studies demonstrate that the granulocyte-macrophage colony-stimulating factor (GM-CSF) also induces CSF-1 transcripts in monocytes. Furthermore, we demonstrate that the detection of CSF-1 RNA in GM-CSF- treated monocytes is associated with synthesis of the CSF-1 gene product. The results thus suggest that GM-CSF may indirectly control specific monocyte functions through the regulation of CSF-1 production. These findings indicate another level of interaction between T cells and monocytes.

A New Cytokine-Based Stratification Is Highly Predictive of Survivals in AML Patients

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1412-1412
Author(s):  
Pierre Peterlin ◽  
Joelle Gaschet ◽  
Thierry Guillaume ◽  
Alice Garnier ◽  
Marion Eveillard ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Risk Stratification ◽  
Univariate Analysis ◽  
Standard Of Care ◽  
Healthy Controls ◽  
First Line ◽  
Serum Samples ◽  
Gm Csf ◽  
Significant Difference ◽  
The Impact

Introduction: Recently, a significant impact of the kinetics of Fms-like tyrosine kinase 3 ligand concentration (FLc) during induction (day[D]1 to D22) has been reported on survivals in first-line acute myeloid leukemia (AML) patients (pts) (Peterlin et al, 2019). Three different FLc profiles were disclosed i) sustained increase of FLc (FLI group, good-risk), ii) increase from D1 to D15, then decrease at D22 (FLD group, intermediate-risk) and iii) stagnation of low levels (<1000 pg/mL, FLL group, high-risk). An update of this prospective monocentric study (www.ClinicalTrials.gov NCT02693899) is presented here evaluating also retrospectively the impact on outcomes of 6 other cytokine level profiles during induction. Methods: Between 05/2016 and 01/2018, 62 AML pts at diagnosis (median age 59 yo [29-71], <60 yo n=33) eligible for first intensive induction were included and provided informed consent. They received standard of care first-line chemotherapy. Serum samples collected on D1, 8, 15 & 22 of induction were frozen-stored until performing ELISA for FL, TNFa, SCF, IL-1b, IL-6, IL-10, GM-CSF. Normal values were assessed in 5 healthy controls. Pts outcomes considered were relapse/leukemia-free (LFS) and overall (OS) survivals. Results: FLI, FLD and FLL profiles were observed for 26, 22 and 14 pts respectively. A total of 372 samples were assayed for the 6 other cytokines. Median concentrations at D1, D8, D15, D22 for these 6 cytokines were as follows, considering the whole cohort (and healthy donors): TNFa: 0.53, 0, 0, 0 (0); SCF: 5.91, 0, 0, 0 (3); IL-1b : 0, 0, 0, 0 (0); IL-6: 4.85, 16.28, 10.11, 7.1 (0), IL-10: 0, 0, 0, 0 (0) and GM-CSF:1.63, 1.8, 0.67, 1.34 (9.98). Median IL-6 and GM-CSF levels, compared to healthy controls, were respectively higher and lower during induction. No significant difference was observed in terms of median cytokine concentrations at any time when comparing the three FL sub-groups or FLI vs FLD pts. With a median follow-up of 28 months (range: 17-37), FLI and FLD pts show now similar 2-y LFS (62.9% vs 59%, p=0.63) and OS (69.2% vs 63.6%, p=0.70). FLL pts have a significantly higher rate of relapse (85,7% vs FLI 19,2% vs FLD 32%, p=0,0001). Comparing FLL vs FLI+FLD pts disclosed significantly different LFS (7.1% vs 61.1%, p<0.001) but not OS (36.7% vs 66.6%, p=0.11). In univariate analysis, 2y LFS and OS were not affected by the concentration (< or > median) of the 7 cytokines studied except for LFS and GM-CSFc at D8 (p=0,04) and D15 (p=0,08), for LFS and FLc at D1 (p=0.06), D8 (p=0,03), D15 (p=0,04) and D22 (p=0,03) and for OS and GM-CSF at D15 (p=0.08). A significant association between LFS was observed with ELN 2017 risk stratification (2-y LFS: favorable: 68,1% vs intermediate: 48,1% vs unfavorable: 30,7%, p=0.03) but not OS (2 y: 77% vs 55,5% vs 46,1%, p=0.09). Multivariate analysis showed that no factor was independently associated with OS while LFS remained significantly associated with the FLc profile (FLL vs others, HR: 5.79. 95%CI: 2.48-13.53, p<0.0001) and GM-CSF at D15 (HR: 0.45; 95%CI: 0.20-0.98, p=0.04) but not with ELN 2017 risk stratification (p=0.06). Cytokine levels were then assessed to try to better discriminate FLI and FLD pts. A significant higher IL-6 level at D22 was found in relapsed or deceased FLI/FLD pts (median:15,34 vs 5,42 pg/mL, p=0,04). FLI/FLD pts with low IL-6 at D22 (< median, 15.5 pg/mL, n=35 vs n=14 with high level) had significant better 2y LFS and OS (74,2% vs 38,4%, p=0,005 and 77,1% vs 38,4%, p=0,009, respectively). A new prognostic risk-stratification could thus be proposed, i.e. FLI/FLD with IL-6 <15.5 pg/mL (favorable), FLI/FLD with IL-6 >15.5 pg/mL (intermediate) and FLL (unfavorable). This new classification was considered for a second multivariate analysis, showing that it is the strongest factor associated with OS (p=0.006, ELN p=0.03, FL profile p=0.04) and LFS (p<0.0001, ELN p=0.005, GM-CSFc D15 p=0.03) (figure 1). Conclusion: This study confirms stagnation of low FLc during AML induction as a strong poor prognosis factor. Moreover, IL-6 levels at D22 further discriminate FLI/FLD pts. Thus, a new cytokine-based risk-stratification integrating FL kinetics and IL-6 levels during induction may help to better predict outcomes in first-line AML patients. These results need to be validated on a larger cohort of AML patients while anti-IL-6 therapy should be tested in combination with standard 3+7 chemotherapy. Figure 1 Disclosures Peterlin: AbbVie Inc: Consultancy; Jazz Pharma: Consultancy; Daiichi-Sankyo: Consultancy; Astellas: Consultancy. Moreau:Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Chevallier:Jazz Pharmaceuticals: Honoraria; Incyte: Consultancy, Honoraria; Daiichi Sankyo: Honoraria.

scholarly journals Comparison of the Inflammatory Responses of Human Meningeal Cells following Challenge with Neisseria lactamica and with Neisseria meningitidis

2006 ◽  
Vol 74 (11) ◽  
pp. 6467-6478 ◽  
Author(s):  
Mark I. Fowler ◽  
Kiave Y. Ho Wang Yin ◽  
Holly E. Humphries ◽  
John E. Heckels ◽  
Myron Christodoulides
Keyword(s):  
Neisseria Meningitidis ◽  
Inflammatory Responses ◽  
Host Cells ◽  
Pathogenic Potential ◽  
Monocyte Chemoattractant Protein 1 ◽  
Gm Csf ◽  
Neisseria Lactamica ◽  
Meningeal Cells ◽  
Macrophage Colony

ABSTRACT The rationale for the present study was to determine how different species of bacteria interact with cells of the human meninges in order to gain information that would have broad relevance to understanding aspects of the innate immune response in the brain. Neisseria lactamica is an occasional cause of meningitis in humans, and in this study we investigated the in vitro interactions between N. lactamica and cells derived from the leptomeninges in comparison with the closely related organism Neisseria meningitidis, a major cause of meningitis worldwide. N. lactamica adhered specifically to meningioma cells, but the levels of adherence were generally lower than those with N. meningitidis. Meningioma cells challenged with N. lactamica and N. meningitidis secreted significant amounts of the proinflammatory cytokine interleukin-6 (IL-6), the C-X-C chemokine IL-8, and the C-C chemokines monocyte chemoattractant protein 1 (MCP-1) and RANTES, but it secreted very low levels of the cytokine growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF). Thus, meningeal cells are involved in the innate host response to Neisseria species that are capable of entering the cerebrospinal fluid. The levels of IL-8 and MCP-1 secretion induced by both bacteria were essentially similar. By contrast, N. lactamica induced significantly lower levels of IL-6 than N. meningitidis. Challenge with the highest concentration of N. lactamica (108 CFU) induced a small but significant down-regulation of RANTES secretion, which was not observed with lower concentrations of bacteria. N. meningitidis (106 to 108 CFU) also down-regulated RANTES secretion, but this effect was significantly greater than that observed with N. lactamica. Although both bacteria were unable to invade meningeal cells directly, host cells remained viable on prolonged challenge with N. lactamica, whereas N. meningitidis induced death; the mechanism was overwhelming necrosis with no significant apoptosis. It is likely that differential expression of modulins between N. lactamica and N. meningitidis contributes to these observed differences in pathogenic potential.

scholarly journals Helminth infection is associated with dampened cytokine responses to viral and bacterial stimulations in Tsimane hunter-horticulturalists

2021 ◽  
Author(s):  
India Schneider-Crease ◽  
Aaron D. Blackwell ◽  
Thomas S. Kraft ◽  
Melissa Emery Thompson ◽  
Ivan Maldonado Suarez ◽  
...  
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Remote Communities ◽  
Necrosis Factor Alpha ◽  
H1n1 Vaccine ◽  
Gm Csf ◽  
Th2 Cytokine ◽  
Cytokine Responses ◽  
Macrophage Colony

AbstractBackgroundSoil-transmitted helminth (STH) infections can catalyze immunological changes that affect the response to subsequent infections, particularly those that elicit strong inflammatory responses. As globalization heightens the risk that remote communities with high STH prevalence will encounter novel pathogens, understanding how STHs shape immune responses to these downstream infections becomes increasingly crucial.MethodologyWe worked with Tsimane forager-horticulturalists in the Bolivian Amazon, where STHs are prevalent. We tested whether STHs and eosinophil levels—most likely indicative of infection in this population—are associated with dampened immune responses to in vitro stimulation with H1N1 and lipopolysaccharide (LPS) antigens. Whole blood samples (n = 179) were treated with H1N1 vaccine and LPS and assayed for 13 cytokines (interferon gamma [INF-γ], interleukin [IL]-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, Granulocyte-macrophage colony-stimulating factor [GM-CSF], and Tumor necrosis factor-alpha [TNF-α]). We evaluated how STHs and eosinophil levels affected cytokine responses and T helper (Th) 1 and Th2-cytokine suite responses to stimulation.ResultsInfection with Ascaris lumbricoides was significantly (p ≤ 0.05) associated with lower response of some cytokines to H1N1 and LPS in women. Eosinophils were significantly negatively associated with some cytokine responses to H1N1 and LPS, with the strongest effects in women, and associated with a reduced Th1- and Th2-cytokine response to H1N1 and LPS in women and men.Conclusions and implicationsWe find that STHs were associated with dampened cytokine responses to certain viral and bacterial antigens, and suggest that this mitigation of host-induced damage may reduce the incidence of cytokine storms in populations with high STH prevalence.

scholarly journals Granulocyte-Macrophage Colony-Stimulating Factor inStaphylococcus aureus-Induced Arthritis

1998 ◽  
Vol 66 (2) ◽  
pp. 853-855 ◽  
Author(s):  
Margareta Verdrengh ◽  
Andrej Tarkowski
Keyword(s):  
Tissue Injury ◽  
Favorable Effect ◽  
Protective Effects ◽  
Colony Stimulating Factor ◽  
Bacterial Inoculation ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
The Impact ◽  
Stimulating Factor

ABSTRACT Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine that is able to increase not only the production of phagocytic cells but also their efficacy with respect to, e.g., bactericidal properties. In this study, we wanted to analyze the impact of GM-CSF on experimental Staphylococcus aureus-induced arthritis. For that purpose, mice were administered GM-CSF before and after bacterial inoculation. Although there was an increase in the total number of leukocytes as well as in the granulocyte fraction, there was no favorable effect on the severity of arthritis or on survival rates. There were no obvious differences between the GM-CSF-pretreated animals and controls with regard to growth of staphylococci in joints and kidneys 4 days after the bacterial inoculation. In contrast, mice that had been pretreated with GM-CSF prior to bacterial inoculation showed approximately four times lower numbers of bacteria in their blood 24 h later. These results, along with those of our previous studies, suggest that on the one hand the granulocyte is the main protective cell during the course of S. aureus infection but that on the other hand, upregulation of granulocyte-macrophage production will not exert any additional protective effects with respect to tissue injury.

scholarly journals Expression of the macrophage-specific colony-stimulating factor in human monocytes treated with granulocyte-macrophage colony-stimulating factor

Blood ◽  
1987 ◽  
Vol 69 (4) ◽  
pp. 1259-1261 ◽  
Author(s):  
J Horiguchi ◽  
MK Warren ◽  
D Kufe
Keyword(s):  
T Cells ◽  
Gene Product ◽  
Phorbol Ester ◽  
Human Monocytes ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Activated Monocytes ◽  
Macrophage Colony ◽  
Stimulating Factor

Abstract The macrophage-specific colony-stimulating factor (CSF-1, M-CSF) regulates the survival, growth and differentiation of monocytes. We have recently demonstrated that phorbol ester induces expression of CSF- 1 in human monocytes. These findings suggested that activated monocytes are capable of producing their own lineage-specific CSF. The present studies demonstrate that the granulocyte-macrophage colony-stimulating factor (GM-CSF) also induces CSF-1 transcripts in monocytes. Furthermore, we demonstrate that the detection of CSF-1 RNA in GM-CSF- treated monocytes is associated with synthesis of the CSF-1 gene product. The results thus suggest that GM-CSF may indirectly control specific monocyte functions through the regulation of CSF-1 production. These findings indicate another level of interaction between T cells and monocytes.

Abrogating chemotherapy-induced myelosuppression by recombinant granulocyte-macrophage colony-stimulating factor in patients with sarcoma: protection at the progenitor cell level.

1992 ◽  
Vol 10 (8) ◽  
pp. 1266-1277 ◽  
Author(s):  
S Vadhan-Raj ◽  
H E Broxmeyer ◽  
W N Hittelman ◽  
N E Papadopoulos ◽  
S P Chawla ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dose Schedule ◽  
Severe Neutropenia ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
The Impact ◽  
Stimulating Factor ◽  
Modified Schedule

PURPOSE The purpose of this study was to optimize the dose, schedule, and timing of recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) administration that would best abrogate myelosuppression in patients with sarcoma. PATIENTS AND METHODS Sarcoma patients who had experienced severe myelosuppression after chemotherapy with Cytoxan (cyclophosphamide; Bristol-Myers Squibb Co, Evansville, IN), Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and dacarbazine ([CyADIC], cycle 1) were eligible. GM-CSF was administered during a 14-day period until 1 week before cycle 2 of CyADIC and was resumed 2 days after cycle 2 completion. The schedule subsequently was modified to allow the earlier administration of GM-CSF in which CyADIC was compressed from 5 days to 3 days, and GM-CSF was administered immediately after the discontinuation of CyADIC in cycle 2. To understand better the impact of GM-CSF on bone marrow stem cells, the proliferative status of bone marrow progenitors was examined during treatment. To evaluate the effects of GM-CSF on effector cells, select functions of mature myeloid cells were also examined. RESULTS In the seven patients who were treated on the initial schedule, GM-CSF enhanced the rate of neutrophil recovery; however, severe neutropenia was not abrogated, By using the modified schedule in 17 patients, GM-CSF significantly reduced both the degree and the duration of neutropenia and myeloid (neutrophils, eosinophils, and monocytes) leukopenia. The mean neutrophil and mature myeloid nadir counts were 100/mm3 and 280/mm3 in cycle 1 and 290/mm3 and 1,540/mm3 in cycle 2 (P less than .01 and P less than .001). The duration of severe neutropenia (neutrophil count less than 500/mm3) and myeloid leukopenia (myeloid leukocyte count less than 1,000/mm3) were reduced from 6.2 and 6.8 days in cycle 1 to 2.8 and 1.4 days in cycle 2 (P less than .001). While 16 of 17 patients experienced severe myeloid leukopenia (less than 500/mm3) in cycle 1, only two of 17 experienced severe myeloid leukopenia in cycle 2 (P less than .001). Overall, severe neutropenia was abrogated in seven patients, which made them eligible for dose-escalation of Adriamycin. The fraction of cycling progenitors increased threefold on GM-CSF and decreased dramatically below the baseline within 1 day of GM-CSF discontinuation. CONCLUSIONS The modified schedule improved the beneficial effects of GM-CSF by enhancing myeloprotection and permitting dose-intensification of chemotherapy. The increased myeloid mass and quiescent progenitors at the initiation of chemotherapy suggest that GM-CSF might allow further chemotherapy dose-rate intensification by shortening the interval between courses.

scholarly journals Early Colorectal Responses to HIV-1 and Modulation by Antiretroviral Drugs

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 231
Author(s):  
Carolina Herrera ◽  
Mike D. McRaven ◽  
Ken G. Laing ◽  
Jayne Dennis ◽  
Thomas J. Hope ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Ex Vivo ◽  
Interferon Γ ◽  
Antiretroviral Drugs ◽  
Limited Information ◽  
Acute Hiv Infection ◽  
Colorectal Tissue ◽  
Gm Csf ◽  
Macrophage Colony ◽  
Hiv 1

Innate responses during acute HIV infection correlate with disease progression and pathogenesis. However, limited information is available about the events occurring during the first hours of infection in the mucosal sites of transmission. With an ex vivo HIV-1 challenge model of human colorectal tissue we assessed the mucosal responses induced by R5- and X4-tropic HIV-1 isolates in the first 24 h of exposure. Microscopy studies demonstrated virus penetration of up to 39 μm into the lamina propia within 6 h of inoculation. A rapid, 6 h post-challenge, increase in the level of secretion of inflammatory cytokines, chemokines, interferon- γ (IFN-γ), and granulocyte-macrophage colony-stimulating factor (GM-CSF) was observed following exposure to R5- or X4-tropic isolates. This profile persisted at the later time point measured of 24 h. However, exposure to the X4-tropic isolate tested induced greater changes at the proteomic and transcriptomic levels than the R5-tropic. The X4-isolate induced greater levels of CCR5 ligands (RANTES, MIP-1α and MIP-1β) secretion than R5-HIV-1. Potential drugs candidates for colorectal microbicides, including entry, fusion or reverse transcriptase inhibitors demonstrated differential capacity to modulate these responses. Our findings indicate that in colorectal tissue, inflammatory responses and a Th1 cytokine profile are induced in the first 24 h following viral exposure.

scholarly journals Human GM-CSF primes neutrophils for enhanced oxidative metabolism in response to the major physiological chemoattractants

Blood ◽  
1987 ◽  
Vol 69 (1) ◽  
pp. 18-21 ◽  
Author(s):  
RH Weisbart ◽  
L Kwan ◽  
DW Golde ◽  
JC Gasson
Keyword(s):  
Oxidative Metabolism ◽  
Superoxide Anion ◽  
Inflammatory Responses ◽  
Leukotriene B4 ◽  
Superoxide Anion Production ◽  
Gm Csf ◽  
Anion Production ◽  
Cytochrome C Reduction ◽  
Macrophage Colony

Abstract Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a T cell- derived lymphokine which induces hematopoietic precursor cells to proliferate in vitro and differentiate to neutrophils and macrophages. GM-CSF also inhibits the motility of mature neutrophils (NIF-T activity), and primes neutrophils to enhance oxidative metabolism in response to the bacterial chemoattractant, N-formyl-methionyl-leucyl- phenylalanine (f-MLP). The present study was designed to determine whether this lymphokine also enhances neutrophil oxidative metabolism in response to the other major physiological chemoattractants which include complement-derived C5a, and the 5-lipoxygenation product of arachidonic acid, leukotriene B4 (LTB4). Superoxide anion production was measured as superoxide dismutase-inhibitable cytochrome C reduction. Purified biosynthetic GM-CSF enhanced superoxide anion production by neutrophils in response to f-MLP, C5a desArg, and LTB4. In contrast to several other factors which prime neutrophils, GM-CSF did not prime for an enhanced oxidative response to phorbol myristate acetate (PMA). These results suggest that GM-CSF may be an endogenous regulator of neutrophil inflammatory responses induced by the major physiological chemoattractants.

scholarly journals Contribution of both STAT and SRF/TCF to c-fos promoter activation by granulocyte-macrophage colony-stimulating factor

Blood ◽  
1996 ◽  
Vol 88 (8) ◽  
pp. 2906-2916 ◽  
Author(s):  
D Rajotte ◽  
HB Sadowski ◽  
A Haman ◽  
K Gopalbhai ◽  
S Meloche ◽  
...  
Keyword(s):  
Binding Site ◽  
Tyrosine Kinases ◽  
Cellular Response ◽  
Dominant Negative ◽  
Colony Stimulating Factor ◽  
Promoter Activation ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor that has been shown to support call proliferation in murine fibroblasts engineered to stably express both chains of the human GM-CSF receptor (NIH-GMR). Because the proto-oncogene c-fos is believed to provide a link between short-term signals elicited at the membrane and long-term cellular response, we chose to study the mechanism of GM-CSF-dependent cell regulation using c-fos promoter activity as a molecular marker in both NIH-GMR transfectants and in the CD34+ cell line TF-1. The importance of c-fos and related AP-1 activity in GM-CSF signalling was suggested by a tight correlation between GM-CSF-dependent activation of the c-fos promoter and cell proliferation and by the inhibitory effect of a trans-dominant c-fos mutant on cell growth. To evaluate the contribution of the serum response factor (SRF) associated with the ternary complex factor (TCF) and of STAT proteins to c-fos promoter activation in response to GM-CSF, the SRF binding site (SRE) and/or the STAT binding site (SIE) were inactivated. In serum-free medium, both SRE and SIE are essential to c-fos promoter activation by GM-CSF in NIH-GMR transfectants and in TF-1 cells. No response to GM-CSF was observed when both sites were mutated. The nature of the STAT family member was further investigated by Wester blots and DNA retardation assays using an SIE probe. Our data indicate that GM-CSF induced DNA binding of both STAT1 and STAT3 in NIH-GMR and mainly of STAT3 in TF-1 cells. STAT5 tyrosine phosphorylation was also observed in TF-1 cells. Finally, expression of a dominant negative MAPK mutant, ERK192A, resulted in a decrease of both SRE- and SIE-dependent activation of c-fos promoter by GM-CSF, suggesting that STAT1/3 are regulated not only by tyrosine kinases, but also partially by MAPK.

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