GRANULOCYTE MACROPHAGE COLONY STIMULATING FACTOR (GM-CSF)
* 'The regulator of innate immune modulation'
** GMCSF is being used in numerous "vaccines" with many individuals testing in a highetend cytokine response to GM-CSF.
*** What are the potential indications contributing to immune confusion - Cytokine Storm?
Therapeutic strategy of BMC transplantation and GM-CSF.
GM-CSF stimulates and mobilizes the bone marrow stem cells (direct pathway).
In addition, GM-CSF can have intrinsic spinal cord repair mechanisms (indirect pathway), including neuroprotection from apoptosis, endogenous stem cell activation, inhibition of glial scar formation, and microglial cell activation.
Hyperbaric Oxygen Therapy elevates or "modulate" (if excessive) the circulating GM CSF
What is G-CSF?
G-CSF is a type of growth factor. Growth factors are proteins made in the body and some of them make the bone marrow produce blood cells and makes stem cells move from the bone marrow into the blood. Stem cells are the cells in the bone marrow from which red blood cells, white cells and platelets develop.
* G-CSF makes the body produce white blood cells to reduce the risk of infection after some types of cancer treatment.
In the body's bone marrow (the soft, sponge-like material found inside bones) blood cells are produced. There are three major types of blood cells; white blood cells, which fight infection; red blood cells, which carry oxygen to and remove waste products from organs and tissues; and platelets, which enable the blood to clot. Cancer treatments such as chemotherapy and radiation therapy can effect these cells which put a person at risk for developing infections, anemia and bleeding problems.
Colony-stimulating factors are substances that stimulate the production of blood cells and promote their ability to function. They do not directly affect tumors but through their role in stimulating blood cells they can be helpful as support of the persons immune system during cancer treatment.
** Sargramostim is a growth factor that stimulates the production, maturation and activation of three types of white blood cells (WBC): neutrophils, macrophages and dendritic cells. Each of these three cells has a distinct purpose and function within the immune system.
* Neutrophils are the most abundant WBC and are the first to responders to the site of an infection. Their purpose is to capture and digest foreign invaders such as bacteria.
* Macrophages also capture and digest foreign invaders but are longer acting and recognize more invaders than neutrophils.
* Dendritic cells make up less than 1% of WBC's but are extremely important. They continuously scan their environment and alert other cells when they find something foreign such as an infection.
For patients receiving chemotherapy
Sargramostim can accelerate the recovery of these white blood cells that can then enhance recovery.
* Sargamostim is also used to stimulate the early stem cells prior to harvesting for peripheral stem cell transplant, and stimulate recovery of bone marrow cells after bone marrow trasplantation.
** Note: We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice.
Discovery of colony-stimulating factors (CSF) resulted in their widespread use to prevent infection in cancer chemotherapy patients,
* AIDS patients and persons with rare white-blood-cell diseases. CSFs are hormone-like substances secreted by cells in tiny amounts. Their release influences white-blood-cell precursors and progenitor cells in bone marrow. When stimulated, progenitor cells divide and produce new white blood cells. The higher the level of CSF secretion, the greater the number of cell divisions and the higher the production of white blood cells.
Healthy persons only need small amounts of CSFs, but patients with low white-blood-cell counts need larger amounts of CSFs to help generate white blood cells quickly. The two major types of white blood cells affected by these factors are granulocytes and macrophages.
** Granulocyte-macrophage colony stimulating factor (GM-CSF) spurs production of both cell types. Because the body produces such low levels and the molecules are too large to be synthesized conventionally as a drug, GM-CSF is produced with recombinant DNA techniques. RCT’s broad patent estate covering GM-CSF is licensed to Schering-Plough, Sanofi, and Amgen. Sanofi, through its acquisition of Genzyme, sells a recombinant form of GM-CSF called Leukine® to stimulate white blood cells in patients receiving chemotherapy and radiotherapy for cancer treatment. Amgen is developing a OncoVEXGM-CSF, an oncolytic vaccine, for the treatment of melanoma, head and neck cancer, breast cancer and pancreatic cancer.
* GM-CSF is a differentially glycosylated growth factor produced by a wide variety of tissue types, including fibroblasts, endothelial cells, T cells, macrophages, mesothelial cells, epithelial cells.
The biological effects of GM-CSF are mediated through its binding to cell surface receptors that widely expressed on hematopoietic cells, as well as some non-hematopoietic cells such as endothelial cells.
* GM-CSF stimulates proliferation, activation, and differentiation of macrophages, granulocytes, neutrophils, eosinophils, and monocytes.
- In most of these tissues, inflammatory mediators, such as IL-1, IL-6, TNFa, or endotoxin, are inducers of GM-CSF gene expression.
** Monitoring of GM-CSF levels may be prognostic in human prostate cancer, poorly healing wounds, thyroid carcinoma, severe mucositis, fungal infections, AIDS, bone marrow transplantation, renal cell carcinoma, prostate cancer, acute lymphoblastic leukemia pulmonary inflammation, hematological malignancies, infection, lung cancer.
Oncotarget. 2018 Jun 15; 9(46): 28226–28239.
Published online 2018 Jun 15. doi: [10.18632/oncotarget.24890]
The impact of granulocyte-macrophage colony stimulating factor (GM-CSF) on hematologic indexes and complications remains existing contradictory evidence in cancer patients after treatment of chemotherapy. Eligible studies up to March 2017 were searched and reviewed from PubMed and Wanfang databases. Totally 1043 cancer patients from 15 studies were included in our research.
The result indicated that GM-CSF could significantly improve white blood cells count (SMD = 1.16, 95% CI: 0.71 – 1.61, Z = 5.03, P < 0.00001) and reduce the time to leukopenia recovery (SMD = -0.85, 95% CI: -1.16 – -0.54, Z = 5.38, P < 0.00001) in cancer patients after treatment of chemotherapy. It also could improve absolute neutrophil count (SMD = 1.11, 95% CI: 0.39 – 1.82, Z = 3.04, P = 0.002) and significantly shorten the time to neutropenia recovery (SMD = -1.47, 95% CI: -2.20 – -1.75, Z = 3.99, P < 0.0001).
- However, GM-CSF could not improve blood platelet (SMD = 0.46, 95% CI: -0.37 – -1.29, Z = 1.10, P = 0.27). And GM-CSF had significant connection with fever (RR = 3.44, 95% CI: 1.43 – 8.28, Z = 2.76, P = 0.006). The publication bias existed in the data of the impact of GM-CSF on blood platelet and complication.
In conclusions, GM-CSF had an intimate association with some hematologic indexes and complications. Our study suggested that more hematological indexes and even more other indexes need to be observed in future studies.
Journal of Neuroinflammation 20118:74 -
GM-CSF reduced production of pro-inflammatory cytokines in monocytes.
GM-CSF attenuates inflammation in the CNS and periphery in mouse model in ALS (Amyotrophic Lateral Sclerosis) and delayed the progression of the disease - Motor Neuron Disease.
GM-CSF increased neutrophil and stem cell counts in the peripheral blood.
GM-CSF decreased inflammation induced TNFa release in primary microglia cells.
GM-CSF decreased the TNFa in bone marrow (BM) monocytes. In addition to reduced TNFa release in BM monocytes the NO release was increased with GM-CSF in BM and spleen.
GM-CSF increase hematopoietic cell populations.
GM-CSF increased the number of total splenocytes.
GM-CSF reduces CNS inflammation and is accompanied with enhanced neuronal function.
TNFa increases 30-fold in spinal cord injury associated with astro and microgliosis indicating significant inflammation.
GM-CSF reduces TNFa production accompanied by modest elevation of NO. NO is normally a pro-inflammatory signaling however it may exert a protective effect in attempt to combat for oxidative stress or increase anti-apoptotic signaling. NO synthesis is increased with HBOT stimulating bone marrow stem cell production and peripheral circulation.
Bone Marrow stem cells has the capacity to 'home' and migrate to sites of hypoxic inflammation ie spinal cord, damaged cardiac cells, peripheral nerves/muscles reducing the inflammatory cascade and promoting regenerative responses.
GM-CSF increases the availability of migratory monocytes with reduced pro inflammatory action.
GM-CSF or erythropoietin had neuroprotective effects and improved neurologic functions after CNS injury [14–18]. These findings suggest that GM-CSF, which is popularly used and considered safe for hematologic disease, could be used for SCI treatment. In our previous study,
GM-CSF decreased neuronal apoptosis and improved the functional outcome in SCI animal models . Preliminary results of our study demonstrated that BMC transplantation and GM-CSF treatment didn’t increase serious complications .
GM-CSF stimulates microglial cells to increase brain-derived neurotrophic factor (BDNF) synthesis . As a result, it was hypothesized that administration of GM-CSF to SCI patients could be an adjunct measure to improve the therapeutic effects of BMC transplantation (Fig. 1). In this study, autologous BMCs were transplanted, and the bone marrow was stimulated with GM-CSF in SCI patients to study the therapeutic and adverse effects of the treatment. GM-CSF Injection Schedule After surgery, a total of five cycles (daily for the first 5 days of each month over 5 months) of GM-CSF (Leucogen; LG Life Science, Seoul, Korea, were injected subcutaneously (250 g/m2 of body surface area). lood was compared with the neurologic outcomes (Fig. 4).
GM-CSF has been used extensively to trigger peripheral leukocytosis and to induce bone marrow hematopoietic stem cell mobilization.
The total number of recruited white blood cells in the peripheral blood was elevated after GM-CSF administration.
The number of white blood cells in patients showing improved neurologic function was significantly higher than that in the patients without neurologic improvement. Spinal MRI Findings Changes in the MRI findings for the patients with treatment are given in Table 4 and Figure 3B.
Overall, 42.9% of patients in the treatment group showed an increase in the diameter of the spinal cord at the cell transplantation site. However, 33.3% of the patients showed atrophic changes (a decrease in diameter) at the transplantation site. Six patients (28.6%) showed evidence of spinal cord enhancement. Other findings, including spinal cord edema demonstrated by increased T2 weight images, cystic degeneration, or spinal cord atrophy distal to the lesion, were observed. But no other significant changes such as tumor formation of the transplanted BMCs were found. STEM CELLS 2007;25:2066 –2073
GM-CSF facilitates development of the immune system and promotes defense against infections
GM-CSF attenuated inflammation in the CNS and the periphery in a mouse model of ALS and thereby delayed the progression of the disease. This mechanism of action targeting inflammation provides a new perspective of the usage of GCSF in the treatment of ALS.
Walter and Eliza Hall Institute for Medical Research (WEHI) in Melbourne.
How GM-CSF works: Colony-Stimulating Factors:
In the body's bone marrow (the soft, sponge-like material found inside bones) blood cells are produced. There are three major types of blood cells; white blood cells, which fight infection; red blood cells, which carry oxygen to and remove waste products from organs and tissues; and platelets, which enable the blood to clot.
Cancer treatments such as chemotherapy and radiation therapy can effect these cells which put a person at risk for developing infections, anemia and bleeding problems.
Colony-stimulating factors are substances that stimulate the production of blood cells and promote their ability to function.
They do not directly affect tumors but through their role in stimulating blood cells they can be helpful as support of the persons immune system during cancer treatment.
Sargramostim is a GM-CSF growth factor that stimulates the production, maturation and activation of three types of white blood cells (WBC): neutrophils, macrophages and dendritic cells.
Each of these three cells has a distinct purpose and function within the immune system. Neutrophils are the most abundant WBC and are the first to responde to the site of an infection. Their purpose is to capture and digest foreign invaders such as bacteria. Macrophages also capture and digest foreign invaders but are longer acting and recognize more invaders than neutrophils. Dendritic cells make up less than 1% of WBC's but are extremely important. They continuously scan their environment and alert other cells when they find something foreign such as an infection.
Sargramostim can accelerate the recovery of these white blood cells that can then enhance recovery. Sargramostim is also used to stimulate the early stem cells prior to harvesting for peripheral stem cell transplant, and stimulate recovery of bone marrow cells after bone marrow transplantation.
Vaccines and GM-CSF
Mol Immunol. 2018 Sep;101:19-28. doi: 10.1016/j.molimm.2018.05.017. Epub 2018 May 28.
Modular MLV-VLPs co-displaying ovalbumin peptides and GM-CSF effectively induce expansion of CD11b+ APC and antigen-specific T cell responses in vitro.
The development of novel vaccination strategies is a persistent challenge to provide effective prophylactic treatments to encounter viral infections. In general, the physical conjugation of selected vaccine components, e.g. antigen and adjuvant, has been shown to enhance the immunogenicity and hence, can increase effectiveness of the vaccine.
- In our proof-of-concept study, we generated non-infectious, replication deficient Murine Leukemia Virus (MLV)-derived virus-like particles (VLPs) that physically link antigen and adjuvant in a modular fashion by co-displaying them on their surface.
- For this purpose, we selected the immunodominant peptides of the model antigen ovalbumin (OVA) and the cytokine granulocyte macrophage-colony stimulating factor (GM-CSF) as non-classical adjuvant.
Our results show that murine GM-CSF displayed on MLV-VLPs mediates expansion and proliferation of CD11b+ cells within murine bone marrow and total spleen cells. Moreover, we show increased immunogenicity of modular VLPs co-displaying OVA peptides and GM-CSF by their elevated capacity to induce OVA-specific T cell-activation and -proliferation within OT-I and OT-II splenocyte cultures. These enhanced effects were not achieved by using an equimolar mixture of VLPs displaying either OVA or GM-CSF. Taken together, OVA and GM-CSF co-displaying MLV-VLPs are able to target and expand antigen presenting cells which in turn results in enhanced antigen-specific T cell activation and proliferation in vitro. These data suggest MLV-VLPs to be an attractive platform to flexibly combine antigen and adjuvant for novel modular vaccination approaches.
J Control Release. 2018 Apr 28;276:1-16. doi: 10.1016/j.jconrel.2018.02.033. Epub 2018 Feb 26.
Stable incorporation of GM-CSF into dissolvable microneedle patch improves skin vaccination against influenza.
The widely used influenza subunit vaccine would benefit from increased protection rates in vulnerable populations. Skin immunization by microneedle (MN) patch can increase vaccine immunogenicity, as well as increase vaccination coverage due to simplified administration. To further increase immunogenicity, we used granulocyte-macrophage colony stimulating factor (GM-CSF), an immunomodulatory cytokine already approved for skin cancer therapy and cancer support treatment. GM-CSF has been shown to be upregulated in skin following MN insertion. The GM-CSF-adjuvanted vaccine induced robust and long-lived antibody responses cross-reactive to homosubtypic and heterosubtypic influenza viruses. Addition of GM-CSF resulted in increased memory B cell persistence relative to groups given influenza vaccine alone and led to rapid lung viral clearance following lethal infection with homologous virus in the mouse model. Here we demonstrate that successful incorporation of the thermolabile cytokine GM-CSF into MN resulted in improved vaccine-induced protective immunity holding promise as a novel approach to improved influenza vaccination. To our knowledge, this is the first successful incorporation of a cytokine adjuvant into dissolvable MNs, thus advancing and
PLoS One. 2018 May 10;13(5):e0196591. doi: 10.1371/journal.pone.0196591. eCollection 2018.
Development of endocytosis, degradative activity, and antigen processing capacity during GM-CSF driven differentiation of murine bone marrow.
Dendritic cells (DC) are sentinels of the immune system, alerting and enlisting T cells to clear pathogenic threats.
As such, numerous studies have demonstrated their effective uptake and proteolytic activities coupled with antigen processing and presentation functions. Yet, less is known about how these cellular mechanisms change and develop as myeloid cells progress from progenitor cells to more differentiated cell types such as DC. Thus, our study comparatively examined these functions at different stages of myeloid cell development driven by the GM-CSF.
To measure these activities at different stages of development, GM-CSF driven bone marrow cells were sorted based on expression of Ly6C, CD115, and CD11c. This strategy enables isolation of cells representing five distinct myeloid cell types: Common Myeloid Progenitor (CMP), Granulocyte/Macrophage Progenitor (GMP), monocytes, monocyte-derived Macrophage/monocyte-derived Dendritic cell Precursors (moMac/moDP), and monocyte-derived DC (moDC).
- We observed significant differences in the uptake capacity, proteolysis, and antigen processing and presentation functions between these myeloid cell populations. CMP showed minimal uptake capacity with no detectable antigen processing and presenting function. The GMP population showed higher uptake capacity, modest proteolytic activity, and little T cell stimulatory function. In the monocyte population, the uptake capacity reached its peak, yet this cell type had minimal antigen processing and presentation function. Finally, moMac/moDP and moDC had a modestly decreased uptake capacity, high degradative capacity and strong antigen processing and presentation functions.
These insights into when antigen processing and presentation function develop in myeloid cells during GM-CSF driven differentiation are crucial to the development of vaccines, allowing targeting of the most qualified cells as an ideal vaccine vehicles.
Cancer Sci. 2018 Jul;109(7):2109-2118. doi: 10.1111/cas.13639. Epub 2018 Jun 21.
Norcantharidin enhances antitumor immunity of GM-CSF prostate cancer cells vaccine by inducing apoptosis of regulatory T cells.
Norcantharidin (NCTD) is a promising antitumor drug with low toxicity. It was reported to be able to regulate immunity, but the mechanism is not yet clear. Here we explored whether NCTD could enhance the antitumor immunity induced by prostate cancer cell vaccine. The results of the in vitro study showed that NCTD induced apoptosis and inhibited proliferation of regulatory T cells (Tregs). Mechanistic research showed that NCTD inhibited Akt activation and activated FOXO1 transcription, resulting in a pro-apoptotic effect. The results of the in vivo study showed that more tumor-infiltrating Tregs existed within peripheral blood and tumor tissue after treatment with the vaccine. Adding NCTD to vaccine treatment could decrease the number of tumor-infiltrating Tregs and increase the number of CD4+ and CD8+ T cells. Combination therapy with NCTD and vaccine was more effective in inhibiting tumor growth than the vaccine alone. In general, this is the first report that NCTD could induce apoptosis of Tregs and enhance the vaccine-induced immunity.
Cancer Immunol Res. 2018 Jun;6(6):723-732. doi: 10.1158/2326-6066.CIR-17-0612. Epub 2018 Apr 18.
PPARγ Contributes to Immunity Induced by Cancer Cell Vaccines That Secrete GM-CSF.
Peroxisome proliferator activated receptor-γ (PPARγ) is a lipid-activated nuclear receptor that promotes immune tolerance through effects on macrophages, dendritic cells (DCs), and regulatory T cells (Tregs). Granulocyte-macrophage colony stimulating factor (GM-CSF) induces PPARγ expression in multiple myeloid cell types.
GM-CSF contributes to both immune tolerance and protection, but the role of PPARγ in these pathways is poorly understood. Here, we reveal an unexpected stimulatory role for PPARγ in the generation of antitumor immunity with irradiated, GM-CSF-secreting tumor-cell vaccines (GVAX). Mice harboring a deletion of pparg in lysozyme M (LysM)-expressing myeloid cells (KO) showed a decreased ratio of CD8+ T effectors to Tregs and impaired tumor rejection with GVAX. Diminished tumor protection was associated with altered DC responses and increased production of the Treg attracting chemokines CCL17 and CLL22. Correspondingly, the systemic administration of PPARγ agonists to vaccinated mice elevated the CD8+ T effector to Treg ratio through effects on myeloid cells and intensified the antitumor activity of GVAX combined with cytotoxic T lymphocyte-associated antigen-4 antibody blockade. PPARγ agonists similarly attenuated Treg induction and decreased CCL17 and CCL22 levels in cultures of human peripheral blood mononuclear cells with GM-CSF-secreting tumor cells. Together, these results highlight a key role for myeloid cell PPARγ in GM-CSF-stimulated antitumor immunity and suggest that PPARγ agonists might be useful in cancer immunotherapy. Cancer Immunol Res; 6(6); 723-32. ©2018 AACR.
Immunology. 2017 Aug;151(4):451-463. doi: 10.1111/imm.12742. Epub 2017 May 16.
Inflammatory responses to influenza vaccination at the extremes of age.
Age affects the immune response to vaccination, with individuals at the extremes of age responding poorly. The initial inflammatory response to antigenic materials shapes the subsequent adaptive response and so understanding is required about the effect of age on the profile of acute inflammatory mediators. In this study we measured the local and systemic inflammatory response after influenza vaccination or infection in neonatal, young adult and aged mice. Mice were immunized intramuscularly with inactivated influenza vaccine with and without the adjuvant MF59 and then challenged with H1N1 influenza. Age was the major factor affecting the inflammatory profile after vaccination: neonatal mice had more interleukin-1α (IL-1α), C-reactive protein (CRP) and granulocyte-macrophage colony-stimulating factor (GMCSF), young adults more tumour necrosis factor-α (TNF), and elderly mice more interleukin-1 receptor antagonist (IL-1RA), IL-2RA and interferon-γ-induced protein 10 (IP10). Notably the addition of MF59 induced IL-5, granulocyte colony-stimulating factor (G-CSF), Keratinocyte Chemotractant (KC) and monocyte chemoattractant protein 1 (MCP1) in all ages of animals and levels of these cytokines correlated with antibody responses. Age also had an impact on the efficacy of vaccination: neonatal and young adult mice were protected against challenge, but aged mice were not. There were striking differences in the localization of the cytokine response depending on the route of exposure: vaccination led to a high serum response whereas intranasal infection led to a low serum response but a high lung response. In conclusion, we demonstrate that age affects the inflammatory response to both influenza vaccination and infection. These age-induced differences need to be considered when developing vaccination strategies for different age groups.
Granulocyte-macrophage colony-stimulating factor neuroprotective activities in Alzheimer's disease mice.
University of Nebraska Medical Center
J Neuroimmunol 2018 Mar 17. Epub 2018 Mar 17.
Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA. Electronic address:
We investigated the effects of granulocyte-macrophage colony stimulating factor (GM-CSF) on behavioral and pathological outcomes in Alzheimer's disease (AD) and non-transgenic mice. GM-CSF treatment in AD mice reduced brain amyloidosis, increased plasma Aβ, and rescued cognitive impairment with increased hippocampal expression of calbindin and synaptophysin and increased levels of doublecortin-positive cells in the dentate gyrus.
These data extend GM-CSF pleiotropic neuroprotection mechanisms in AD and include regulatory T cell-mediated immunomodulation of microglial function, Aβ clearance, maintenance of synaptic integrity, and induction of neurogenesis. Together these data support further development of GM-CSF as a neuroprotective agent for AD.
The role of granulocyte macrophage colony stimulating factor (GM-CSF) in radiation-induced tumor cell migration.
Clin Exp Metastasis 2018 Mar 13. Epub 2018 Mar 13.
Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, 269 Campus Dr., CCSR South Rm. 1255A, Stanford, CA, 94305-5152, USA.
Recently it has been observed in preclinical models that that radiation enhances the recruitment of circulating tumor cells to primary tumors, and results in tumor regrowth after treatment. This process may have implications for clinical radiotherapy, which improves control of a number of tumor types but which, despite continued dose escalation and aggressive fractionation, is unable to fully prevent local recurrences. By irradiating a single tumor within an animal bearing multiple lesions, we observed an increase in tumor cell migration to irradiated and unirradiated sites, suggesting a systemic component to this process.
Previous work has identified the cytokine GM-CSF, produced by tumor cells following irradiation, as a key effector of this process. We evaluated the ability of systemic injections of a PEGylated form of GM-CSF to stimulate tumor cell migration. While increases in invasion and migration were observed for tumor cells in a transwell assay, we found that daily injections of PEG-GM-CSF to tumor-bearing animals did not increase migration of cells to tumors, despite the anticipated changes in circulating levels of granulocytes and monocytes produced by this treatment. Combination of PEG-GM-CSF treatment with radiation also did not increase tumor cell migration. These findings suggest that clinical use of GM-CSF to treat neutropenia in cancer patients will not have negative effects on the aggressiveness of residual cancer cells. However, further work is needed to characterize the mechanism by which GM-CSF facilitates systemic recruitment of trafficking tumor cells to tumors.
Immunomodulatory treatment with systemic GM-CSF augments pulmonary immune responses and improves neurological outcome after experimental stroke.
J Neuroimmunol 2018 Mar 9. Epub 2018 Mar 9.
Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Medical Immunology, Germany; Labor Berlin-Charité Vivantes, Berlin, Germany.
Stroke-induced immunodepression is an independent risk factor for stroke-associated pneumonia (SAP). Granulocyte-macrophage colony stimulating factor (GM-CSF) has neuroprotective properties in experimental stroke and been demonstrated to reverse immunodepression in sepsis patients. However, whether GM-CSF restores immune function after stroke preventing SAP and improving outcome is unknown. Here, we demonstrated that GM-CSF treatment improved peripheral and pulmonary leukocyte numbers, peripheral cytokine responses, lowered lung bacterial burden in the early course and improved long-term functional outcome after experimental stroke.
These data suggest that GM-CSF is promising for stroke treatment since it not only acts neuroprotective in the ischemic brain but may also protect against detrimental post-stroke infections.
Targeting myeloid cells in the tumor sustaining microenvironment.
Cell Immunol 2017 Nov 2. Epub 2017 Nov 2.
Department of Dermatology, University Medical Center, Mainz, Germany.
Myeloid cells are the most abundant cells in the tumor microenvironment (TME). The tumor recruits and modulates endogenous myeloid cells to tumor-associated macrophages (TAM), dendritic cells (DC), myeloid-derived suppressor cells (MDSC) and neutrophils (TAN), to sustain an immunosuppressive environment. Pathologically overexpressed mediators produced by cancer cells like granulocyte-macrophage colony-stimulating- and vascular endothelial growth factor induce myelopoiesis in the bone marrow.
Excess of myeloid cells in the blood, periphery and tumor has been associated with tumor burden. In cancer, myeloid cells are kept at an immature state of differentiation to be diverted to an immunosuppressive phenotype. Here, we review human myeloid cells in the TME and the mechanisms for sustaining the hallmarks of cancer. Simultaneously, we provide an introduction into current and novel therapeutic approaches to redirect myeloid cells from a cancer promoting to a rather inflammatory, cancer inhibiting phenotype. In addition, the role of platelets for tumor promotion is discussed.
Oncol Lett. 2017 Oct;14(4):4701-4707. doi: 10.3892/ol.2017.6738. Epub 2017 Aug 9.
Decreased expression of granulocyte-macrophage colony-stimulating factor is associated with adverse clinical outcome in patients with gastric cancer undergoing gastrectomy.
Previous studies have revealed the clinical significance of tumor-associated macrophages (TAMs) in gastric cancer, whereas the role of the cytokines that orchestrate TAM polarization in gastric cancer remains elusive. The present study aimed to evaluate the prognostic value of granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in patients with gastric cancer. Intratumoral GM-CSF expression was investigated by immunohistochemical staining in 408 retrospectively enrolled patients. Kaplan-Meier analysis and Cox regression models were used to evaluate the prognostic value of GM-CSF expression. Predictive nomograms were generated to predict the overall survival and disease-free survival rates of the patients.
Decreased intratumoral GM-CSF expression was identified, and indicated a poorer clinical outcome for patients with gastric cancer, particularly in advanced stages. Intratumoral GM-CSF expression may provide an additional risk stratification for the prognosis of patients with gastric cancer based on the Tumor-Node-Metastasis (TNM) staging system. Cox multivariate analysis identified GM-CSF expression as an independent prognostic factor for overall survival and disease-free survival time. The generated nomograms performed well in predicting the 3-and 5-year clinical outcome of patients with gastric cancer.
In conclusion, GM-CSF is a potential independent prognostic indicator for patients with gastric cancer, which may be integrated with TNM staging systems to improve the predictive accuracy for clinical outcome, particularly in advanced tumors.
Neurodegener Dis. 2017;17(1):1-13. Epub 2016 Aug 20.
Granulocyte Colony-Stimulating Factor Ameliorates Skeletal Muscle Dysfunction in Amyotrophic Lateral Sclerosis Mice and Improves Proliferation of SOD1-G93A Myoblasts in vitro.
Amyotrophic lateral sclerosis (ALS) causes loss of upper and lower motor neurons as well as skeletal muscle (SKM) dysfunction and atrophy. SKM is one of the tissues involved in the development of ALS pathology, and studies in a SOD1-G93A mouse model of ALS have demonstrated alterations in SKM degeneration/regeneration marker expression in vivo and defective mutant myoblast proliferation in vitro. Granulocyte colony-stimulating factor (G-CSF) has been shown to alleviate SOD1-G93A pathology. However, it is unknown whether G-CSF may have a direct effect on SKM or derived myoblasts.
To investigate effects of G-CSF and its analog pegfilgrastim (PEGF) on SOD1-G93A- associated SKM markers in vivo and those of G-CSF on myoblast proliferation in vitro.
The effect of PEGF treatment on hematopoietic stem cell mobilization, survival, and motor function was determined. RNA expression of SKM markers associated with mutant SOD1 expression was quantified in response to PEGF treatment in vivo, and the effect of G-CSF on the proliferation of myoblasts derived from mutant and control muscles was determined in vitro.
Positive effects of PEGF on hematopoietic stem cell mobilization, survival, and functional assays in SOD1-G93A animals were confirmed. In vivo PEGF treatment augmented the expression of its receptor Csf3r and alleviated typical markers for mutant SOD1 muscle. Additionally, G-CSF was found to directly increase the proliferation of SOD1-G93A, but not wild-type primary myoblasts in vitro.
Our results support the beneficial role of the G-CSF analog PEGF in a SOD1-G93A model of ALS. Thus, G-CSF and its analogs may be directly beneficial in diseases where the SKM function is compromised.
J Cereb Blood Flow Metab. 2016 Nov;36(11):1978-1991. Epub 2016 Jul 21.
Intracerebral GM-CSF contributes to transendothelial monocyte migration in APP/PS1 Alzheimer's disease mice.
Although tight junctions between human brain microvascular endothelial cells in the blood-brain barrier prevent molecules or cells in the bloodstream from entering the brain, in Alzheimer's disease, peripheral blood monocytes can "open" these tight junctions and trigger subsequent transendothelial migration. However, the mechanism underlying this migration is unclear. Here, we found that the CSF2RB, but not CSF2RA, subunit of the granulocyte-macrophage colony-stimulating factor receptor was overexpressed on monocytes from Alzheimer's disease patients. CSF2RB contributes to granulocyte-macrophage colony-stimulating factor-induced transendothelial monocyte migration. Granulocyte-macrophage colony-stimulating factor triggers human brain microvascular endothelial cells monolayer tight junction disassembly by downregulating ZO-1 expression via transcription modulation and claudin-5 expression via the ubiquitination pathway. Interestingly, intracerebral granulocyte-macrophage colony-stimulating factor blockade abolished the increased monocyte infiltration in the brains of APP/PS1 Alzheimer's disease model mice.
Our results suggest that in Alzheimer's disease patients, high granulocyte-macrophage colony-stimulating factor levels in the brain parenchyma and cerebrospinal fluid induced blood-brain barrier opening, facilitating the infiltration of CSF2RB-expressing peripheral monocytes across blood-brain barrier and into the brain. CSF2RB might be useful as an Alzheimer's disease biomarker. Thus, our findings will help to understand the mechanism of monocyte infiltration in Alzheimer's disease pathogenesis.
Cancer Immunol Res. 2016 Sep 29. pii: canimm.0042.2016. [Epub ahead of print]
Systemic GM-CSF recruits effector T cells into the tumor microenvironment in localized prostate cancer.
Granulocytic-macrophage colony-stimulating factor (GM-CSF) is used as an adjuvant in cancer vaccine trials and has the potential to enhance antitumor efficacy with immunotherapy; however, its immunologic effects are not fully understood. Here, we report results from a phase 1 study of neoadjuvant GM-CSF in patients with localized prostate cancer undergoing radical prostatectomy. Patients received subcutaneous injections of GM-CSF (250 microg/m2/day) daily for 2 weeks (Cohort 1; n = 6), 3 weeks (Cohort 2; n = 6), or 4 weeks (Cohort 3; n = 6). Treatment was well tolerated with all grade 1 or 2 adverse events. Two patients had a decline in prostate-specific antigen (PSA) of more than 50%. GM-CSF treatment increased the numbers of circulating mature myeloid dendritic cells, proliferating conventional CD4 T cells, proliferating CD8 T cells, and to a lesser magnitude FoxP3+ regulatory CD4 T cells. Although GM-CSF treatment did not augment antigen-presenting cell localization to the prostate, treatment was associated with recruitment of CD8+ T cells to the tumor. These results suggest that systemic GM-CSF can modulate T-cell infiltration in the tumor microenvironment.
J Neuroinflammation. 2016 Sep 27;13(1):255.
Loss of Schwann cell plasticity in chronic inflammatory demyelinating polyneuropathy (CIDP).
Chronic inflammatory demyelinating polyneuropathy (CIDP) is often associated with chronic disability, which can be accounted to incomplete regeneration of injured axons. We hypothesized that Schwann cell support for regenerating axons may be altered in CIDP, which may account for the poor clinical recovery seen in many patients.
We exposed human and rodent Schwann cells to sera from CIDP patients and controls. In a model of chronic nerve denervation, we transplanted these conditioned Schwann cells intraneurally and assessed their capacity to support axonal regeneration by electrophysiology and morphometry.
CIDP-conditioned Schwann cells were less growth supportive for regenerating axons as compared to Schwann cells exposed to control sera. The loss of Schwann cell support was associated with lower levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) in CIDP sera and correlated with altered expression of c-Jun and p57kip2 in Schwann cells. The inactivation of these regulatory factors resulted in an altered expression of neurotrophins including BDNF, GDNF, and NGF in CIDP-conditioned Schwann cells in vitro.
Our study provides evidence that pro-regenerative functions of Schwann cells are affected in CIDP. It thereby offers a possible explanation for the clinical observation that in many CIDP patients recovery is incomplete despite sufficient immunosuppressive treatment.
BMC Immunol. 2016 Sep 26;17(1):31.
An effective cytokine adjuvant vaccine induces autologous T-cell response against colon cancer in an animal model.
Despite recent advances in early detection and improvements in chemotherapy for colon cancer, the patients still face poor prognosis of postoperative recurrence and metastasis, the median survival for patients with metastatic colorectal cancer is approximately 22-24 months. Some immunotherapeutic approaches had been attempted in colon cancer patients to significantly increase overall survival. A vaccine based approach has shown a novel direction for colon cancer prevention and therapy.
In this study, the experiments were designed including prevention and therapeutic stages in order to attain effect against tumor recurrence in clinical settings. The anti-tumor efficacy of a novel cytokine adjuvant vaccine that contained cytokines GM-CSF and IL-2 and inactivated colon CT26.WT whole cell antigen was evaluated in BALB/c mouse tumor models by measuring tumor growth post vaccination and the survival time of tumor-bearing mice, analyzing the expression and distribution of CD4, CD8, CD11c, CD80, CD86 and CD83 positive cells in control and treated mice by flow cytometry and immunochemistry. The tumor-specific cytotoxic T cells (CTL) were analyzed by tumor proliferation and the lactic dehydrogenates (LDH) release assays. IFN-γ, IL-2 and GM-CSF secretion in serum was assayed by ELISA.
Our results suggested that cytokine adjuvant vaccine significantly inhibited tumor growth and extended the survival period at least 160d. It was found that the levels of CD8 + T and the tumor-specific cytotoxicity were significantly higher in prevention and treatment group vaccinated by cytokine adjuvant vaccine. CD8 + T cells play a key role in anti-tumor response.
The novel GM-CSF and IL-2 based adjuvant vaccine effectively activated autologous T-cell response and represented a promising immunotherapeutic approach for patients with colon cancer.
Journal of Neuroinflammation 20118:74
GCSF attenuated inflammation in the CNS and the periphery in a mouse model of ALS and thereby delayed the progression of the disease. This mechanism of action targeting inflammation provides a new perspective of the usage of GCSF in the treatment of ALS.
GCSF is a hematopoietic growth factor which is currently in clinical use to mobilize stem cells into the circulation prior to apheresis  and to treat neutropenia after cytostatic therapy. GCSF has a wide variety of actions; it reduces apoptosis, drives neurogenesis and angiogenesis and attenuates inflammation [17, 18, 19, 20, 21, 22]. GCSF is protective in myocardial infarction in animal models and it has also been tested for clinical use after acute and chronic ischemic heart diseases as reviewed by Kastrup et al. . Moreover, GCSF has been shown to be protective in animal models of acute and chronic neurodegenerative diseases as reviewed in Diederich et al. , including stroke, Alzheimer's disease, Parkinson's disease and spinal cord injury [25, 26, 27]. GCSF was recently shown to be protective also in animal models of ALS , mediating its protective effects via P13/Akt pathway, an antiapoptotic transduction pathway downstream of GCSF signaling in neurons . GCSF was also shown to be neuroprotective after peripheral axotomy [29, 30].
In humans, GCSF administration increases the production of hematopoietic stem cells, granulocytes and monocytes . GCSF therapy has been in phase I clinical trials for ALS where it has been proven to be a safe treatment for ALS [36, 37, 38, 39]. However, the mechanism of action of GCSF is not fully known in ALS.
Pegfilgrastim also modulated the inflammatory cell populations in the bone marrow (BM) and spleen in mutant SOD1 mice and reduced the production of pro-inflammatory cytokine TNFα. GCSF also reduced the inflammatory activation of microglia in vitro. After long-term pegfilgrastim treatment, the increased storage of Ly6C cells in the BM and spleen was accompanied by increased migration of monocytes, or their survival in the degenerative muscle at the symptomatic stage of ALS. This suggests that GCSF therapy delays the progression of ALS in a transgenic mouse model through the attenuation of inflammation in both the CNS and the periphery.
GCSF has proven to be a safe treatment in ALS in phase I studies, administered as a single [36, 37] or repeated cycles with three months interval [38, 39]. GCSF mobilizes hematopoietic stem cells from ALS patients in a consistent manner  and GCSF-mobilized stem cells could be transplanted back to ALS patients causing no adverse effects . The clinical trials so far have shown limited improvement in ALS pathology. The reason for this may be the fact that GCSF was administered for a short period of time; only single or repeated cycles of few days of duration were given.
The induction of motoneuron death and neurodegeneration in ALS has been described as a "dying forward" manner where the motoneuronal pathology starts from at the soma , or as a "dying back" manner where the motoneuronal pathology starts at the distal axons and proceeds back to the motoneuron soma . Since GCSF exerts its inflammation-modulating effects in the CNS and the periphery, it may hinder the disease progression at multiple sites. In our study, GCSF strongly modulated the composition of inflammatory cell populations, their availability and potentially also their migration into degenerative muscle in a mouse model of ALS. It remains to be further investigated whether i) the transplantation of BM or spleen cells obtained from GCSF-mobilized mouse or ii) the transplantation of ex vivo GCSF-treated monocytes is sufficient to achieve the GCSF-mediated protection in a mouse model of ALS and which monocyte subpopulations in particular are involved in these processes.
The present data demonstrate that GCSF attenuates inflammation in a mouse model of ALS which slows down the progression of the disease. GCSF reduced inflammation in the CNS and the periphery while increasing the availability of anti-inflammatory migratory monocytes. This mechanism of action targeting neuroinflammation and peripheral inflammation-participative cells provides a new perspective of the usage of GCSF in the treatment of ALS.
To assess the safety and therapeutic efficacy of autologous human bone marrow cell (BMC) transplantation and the administration of granulocyte macrophage-colony stimulating factor (GM-CSF), a phase I/II open-label and nonrandomized study was conducted on 35 complete spinal cord injury patients. The BMCs were transplanted by injection into the surrounding area of the spinal cord injury site within 14 injury days (n 17), between 14 days and 8 weeks (n 6), and at more than 8 weeks (n 12) after injury. In the control group, all patients (n 13) were treated only with conventional decompression and fusion surgery without BMC transplantation. The patients underwent preoperative and follow-up neurological assessment using the American Spinal Injury Association Impairment Scale (AIS), electrophysiological monitoring, and magnetic resonance imaging (MRI). The mean follow-up period was 10.4 months after injury. At 4 months, the MRI analysis showed the enlargement of spinal cords and the small enhancement of the cell implantation sites, which were not any adverse lesions such as malignant transformation, hemorrhage, new cysts, or infections. Furthermore, the BMC transplantation and GM-CSF administration were not associated with any serious adverse clinical events increasing morbidities. The AIS grade increased in 30.4% of the acute and subacute treated patients (AIS A to B or C), whereas no significant improvement was observed in the chronic treatment group. Increasing neuropathic pain during the treatment and tumor formation at the site of transplantation are still remaining to be investigated. Long-term and large scale multicenter clinical study is required to determine its precise therapeutic effect.
Cell Res. 2006 Feb;16(2):126-33.
Granulocyte-macrophage colony-stimulating factor (GM-CSF) and T-cell responses: what we do and don't know.
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is an important hematopoietic growth factor and immune modulator. GM-CSF also has profound effects on the functional activities of various circulating leukocytes. It is produced by a variety of cell types including T cells, macrophages, endothelial cells and fibroblasts upon receiving immune stimuli. Although GM-CSF is produced locally, it can act in a paracrine fashion to recruit circulating neutrophils, monocytes and lymphocytes to enhance their functions in host defense. Recent intensive investigations are centered on the application of GM-CSF as an immune adjuvant for its ability to increase dendritic cell (DC) maturation and function as well as macrophage activity. It is used clinically to treat neutropenia in cancer patients undergoing chemotherapy, in AIDS patients during therapy, and in patients after bone marrow transplantation. Interestingly, the hematopoietic system of GM-CSF-deficient mice appears to be normal; the most significant changes are in some specific T cell responses. Although molecular cloning of GM-CSF was carried out using cDNA library of T cells and it is well known that the T cells produce GM-CSF after activation, there is a lack of systematic investigation of this cytokine in production by T cells and its effect on T cell function. In this article, we will focus mainly on the immunobiology of GM-CSF in T cells.
Purpose: We investigated the synergistic effect of hyperbaric oxygen (HBO) and granulocyte-colony stimulating factor (G-CSF) on adhesion formation in rats. Methods: 40 adult male Sprague-Dawley rats (250-350g) were divided into 4 groups. In group-1, no further management was undertaken. Group-2 received HBO therapy, group-3 was treated with 50ug/kg subcutaneous G-CSF once daily for 7 days following laparatomy and cecal abrasion and group-4 was given both G-CSF and HBO therapies. On the 7th day, all rats were sacrificed and adhesions were scored. Tissue samples from adhesions and peritonea and cecum wall were examined both pathologically and biochemically for tissue hydroxyproline content. Results: No mortality occurred in study groups. When the groups were evaluated according to the adhesion numbers and grades, there was a statistically significant difference between the control and groups 3 and 4 (P<0.001). There was no statistically significant difference between groups 1 and 2 (p>0.05). HBO + G-CSF group was significantly different from control, HBO and G-CSF groups, regarding hydroxyproline contents (p=0.005). Inflammation and fibrosis did not differ significantly among the groups (p=0.248), (p=0.213).
Conclusion: HBO treatment could not reduce the adhesion formation alone.
Combined use of HBO and G-CSF, has a markedly preventive effect on postoperative adhesion formation.