Project description:M-CSF and GM-CSF are 2 important cytokines that regulate macrophage numbers and function. Here, we review their known effects on cells of the macrophage-monocyte lineage. Important clues to their function come from their expression patterns. M-CSF exhibits a mostly homeostatic expression pattern, whereas GM-CSF is a product of cells activated during inflammatory or pathologic conditions. Accordingly, M-CSF regulates the numbers of various tissue macrophage and monocyte populations without altering their "activation" status. Conversely, GM-CSF induces activation of monocytes/macrophages and also mediates differentiation to other states that participate in immune responses [i.e., dendritic cells (DCs)]. Further insights into their function have come from analyses of mice deficient in either cytokine. M-CSF signals through its receptor (CSF-1R). Interestingly, mice deficient in CSF-1R expression exhibit a more significant phenotype than mice deficient in M-CSF. This observation was explained by the discovery of a novel cytokine (IL-34) that represents a second ligand of CSF-1R. Information about the function of these ligands/receptor system is still developing, but its complexity is intriguing and strongly suggests that more interesting biology remains to be elucidated. Based on our current knowledge, several therapeutic molecules targeting either the M-CSF or the GM-CSF pathways have been developed and are currently being tested in clinical trials targeting either autoimmune diseases or cancer. It is intriguing to consider how evolution has directed these pathways to develop; their complexity likely mirrors the multiple functions in which cells of the monocyte/macrophage system are involved.
Project description:Concerns have been raised about potential toxic interactions when colony-stimulating factors (CSFs) and chemoradiation are concurrently performed. In 2006, the ASCO guidelines advised against their concomitant use. Nevertheless, with the development of modern radiotherapy techniques and supportive care, the therapeutic index of combined chemotherapy, radiotherapy, and CSFs is worth reassessing. Recent clinical trials testing chemoradiation in lung cancer let investigators free to decide the use of concomitant CSFs or not. No abnormal infield event was reported after the use of modern radiotherapy techniques and concomitant chemotherapy regimens. These elements call for further investigation to set new recommendations in favour of the association of chemoradiation and CSFs. Moreover, radiotherapy could induce anticancer systemic effects mediated by the immune system in vitro and in vivo. With combined CSFs, this effect was reinforced in preclinical and clinical trials introducing innovative radioimmunotherapy models. So far, the association of radiation with CSFs has not been combined with immunotherapy. However, it might play a major role in triggering an immune response against cancer cells, leading to abscopal effects. The present article reassesses the therapeutic index of the combination CSFs-chemoradiation through an updated review on its safety and efficacy. It also provides a special focus on radioimmunotherapy.
Project description:HIV-1 acquisition can be prevented by broadly neutralizing antibodies (BrNAbs) that target the envelope glycoprotein complex (Env). An ideal vaccine should therefore be able to induce BrNAbs that can provide immunity over a prolonged period of time, but the low intrinsic immunogenicity of HIV-1 Env makes the elicitation of such BrNAbs challenging. Co-stimulatory molecules can increase the immunogenicity of Env and we have engineered a soluble chimeric Env trimer with an embedded granulocyte-macrophage colony-stimulating factor (GM-CSF) domain. This chimeric molecule induced enhanced B and helper T cell responses in mice compared to Env without GM-CSF. We studied whether we could optimize the activity of the embedded GM-CSF as well as the antigenic structure of the Env component of the chimeric molecule. We assessed the effect of truncating GM-CSF, removing glycosylation-sites in GM-CSF, and adjusting the linker length between GM-CSF and Env. One of our designed Env(GM-CSF) chimeras improved GM-CSF-dependent cell proliferation by 6-fold, reaching the same activity as soluble recombinant GM-CSF. In addition, we incorporated GM-CSF into a cleavable Env trimer and found that insertion of GM-CSF did not compromise Env cleavage, while Env cleavage did not compromise GM-CSF activity. Importantly, these optimized Env(GM-CSF) proteins were able to differentiate human monocytes into cells with a macrophage-like phenotype. Chimeric Env(GM-CSF) should be useful for improving humoral immunity against HIV-1 and these studies should inform the design of other chimeric proteins.
Project description:In this study, we compared human monocytes differentiated for 7 days with M-CSF and/or GM-CSF. A comparison of the different macrophage populations was made using microarray profiling. Threshold: 1.0 . Logbase: 2 . Technology: Agilent.SingleColor.14850. Normalization: Shift to 75 percentile . Baseline Transformation: median of all samples . FlagSettings:. Feature is not Uniform:A. Feature is a population outlier:A. Feature is Saturated:A. Feature is not above background:M. Feature is not positive and significant:M.
Project description:Macrophages are crucial in controlling infectious agents and tissue homeostasis. Macrophages require a wide range of functional capabilities in order to fulfill distinct roles in our body, one being rapid and robust immune responses. To gain insight into macrophage plasticity and the key regulatory protein networks governing their specific functions, we performed quantitative analyses of the proteome and phosphoproteome of murine primary GM-CSF and M-CSF grown bone marrow derived macrophages (GM-BMMs and M-BMMs, respectively) using the latest isobaric tag based tandem mass tag (TMT) labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Strikingly, metabolic processes emerged as a major difference between these macrophages. Specifically, GM-BMMs show significant enrichment of proteins involving glycolysis, the mevalonate pathway, and nitrogen compound biosynthesis. This evidence of enhanced glycolytic capability in GM-BMMs is particularly significant regarding their pro-inflammatory responses, because increased production of cytokines upon LPS stimulation in GM-BMMs depends on their acute glycolytic capacity. In contrast, M-BMMs up-regulate proteins involved in endocytosis, which correlates with a tendency toward homeostatic functions such as scavenging cellular debris. Together, our data describes a proteomic network that underlies the pro-inflammatory actions of GM-BMMs as well as the homeostatic functions of M-BMMs.
Project description:ObjectiveThis meta-analysis aims to assess the efficacy and safety of granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies on COVID-19.MethodsRelevant literatures about GM-CSF antibody treatment in COVID-19 patients were searched from the PubMed, Cochrane Library, Embase, Google scholar, and Baiduscholar databases from the COVID-19 outbreak in December 2019 until 1 January 2021. The primary outcomes included the death, intensive care unit (ICU) admission risk, ventilation requirement, and secondary infection.ResultsA total of 12 eligible literature involving 8979 COVID-19 patients were recruited, and they were divided into experimental group (n = 2673) and control group (n = 6306). Using a random-effect model, it is found that the GM-CSF antibody treatment was associated with a 23% decline of the risk of death [odd's ratio (OR): 0.34, 95% confidence interval (CI): 0.21-0.56, p < 0.0001] and a 20% enhancement of ventilation (OR: 1.47, 95% CI: 1.19, 1.80, p = 0.0002). GM-CSF antibody treatment did not have a significant correlation to secondary infection and increased risk of ICU admission in COVID-19 patients, which may be attributed to the older age and the length of stay.ConclusionsSevere COVID-19 patients can benefit from GM-CSF antibodies.
Project description:ObjectiveTo determine the presence and spatial distribution of different macrophage phenotypes, governed by granulocyte macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) skewing signals, in giant cell arteritis (GCA) lesions.MethodsTemporal artery biopsies (TABs, n = 11) from treatment-naive GCA patients, aorta samples from GCA-related aneurysms (n = 10) and atherosclerosis (n = 10) were stained by immunohistochemistry targeting selected macrophage phenotypic markers, cytokines, matrix metalloproteinases (MMPs) and growth factors. In vitro macrophage differentiation (n = 10) followed by flow cytometry, Luminex assay and ELISA were performed to assess whether GM-CSF and M-CSF are drivers of macrophage phenotypic heterogeneity.ResultsA distinct spatial distribution pattern of macrophage phenotypes in TABs was identified. CD206+/MMP-9+ macrophages were located at the site of tissue destruction, whereas FRβ+ macrophages were located in the inner intima of arteries with high degrees of intimal hyperplasia. Notably, this pattern was also observed in macrophage-rich areas in GCA aortas but not in atherosclerotic aortas. Flow cytometry showed that GM-CSF treatment highly upregulated CD206 expression, while FRβ was expressed by M-CSF-skewed macrophages, only. Furthermore, localised expression of GM-CSF and M-CSF was detected, likely contributing to macrophage heterogeneity in the vascular wall.ConclusionsOur data document a distinct spatial distribution pattern of CD206+/MMP-9+ macrophages and FRβ+ macrophages in GCA linked to tissue destruction and intimal proliferation, respectively. We suggest that these distinct macrophage phenotypes are skewed by sequential GM-CSF and M-CSF signals. Our study adds to a better understanding of the development and functional role of macrophage phenotypes in the pathogenesis of GCA and opens opportunities for the design of macrophage-targeted therapies.
Project description:Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic cytokine that activates granulocyte and macrophage cell lineages. It is also known to have an important function in wound healing. This study investigated the effect of GM-CSF in wound healing of human corneal epithelial cells (HCECs). We used human GM-CSF derived from rice cells (rice cell-derived recombinant human GM-CSF; rhGM-CSF). An in vitro migration assay was performed to investigate the migration rate of HCECs treated with various concentrations of rhGM-CSF (0.1, 1.0, and 10.0 ?g/ml). MTT assay and flow cytometric analysis were used to evaluate the proliferative effect of rhGM-CSF. The protein level of p38MAPK was analyzed by western blotting. For in vivo analysis, 100 golden Syrian hamsters were divided into four groups, and their corneas were de-epithelialized with alcohol and a blade. The experimental groups were treated with 10, 20, or 50 ?g/ml rhGM-CSF four times daily, and the control group was treated with phosphate-buffered saline. The corneal wound-healing rate was evaluated by fluorescein staining at the initial wounding and 12, 24, 36, and 48 hours after epithelial debridement. rhGM-CSF accelerated corneal epithelial wound healing both in vitro and in vivo. MTT assay and flow cytometric analysis revealed that rhGM-CSF treatment had no effects on HCEC proliferation. Western blot analysis demonstrated that the expression level of phosphorylated p38MAPK increased with rhGM-CSF treatment. These findings indicate that rhGM-CSF enhances corneal wound healing by accelerating cell migration.
Project description:ObjectivesWe investigated the development of binding and neutralizing antibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients receiving prolonged therapy with GM-CSF as adjuvant therapy of melanoma and the impact of these antibodies on biological effects.MethodsFifty-three patients with high-risk melanoma that had been surgically excised were treated with GM-CSF, 125 μg/m daily for 14 days every 28 days for 1 year after surgical resection of disease. Serum samples for antibodies to GM-CSF were measured before treatment and on study days 155 and 351. Blood draws for testing biological effects were keyed to GM-CSF administration: days 0 (before), 15 (after 14 d on GM-CSF), 29 (after 14 d off GM-CSF), 155, and 351 (after 14 d on GM-CSF in the sixth and 13th cycle of treatment).ResultsOf 53 patients enrolled, 43 were evaluable for the development of anti-GM-CSF antibodies. Of these, 93% developed binding antibodies and 42% developed both binding and neutralizing antibodies. The increase in the white blood cell count, percent eosinophils, or neopterin levels engendered by GM-CSF administration was abrogated or markedly decreased in patients with neutralizing antibodies but not in patients who developed only binding antibodies.ConclusionsNinety-three percent of patients with melanoma treated with GM-CSF as adjuvant therapy develop antibodies to GM-CSF. In those with neutralizing antibodies, a diminution of the biological effects of GM-CSF was observed. The development of neutralizing antibodies might also abrogate the potential clinical benefit of this treatment and should be considered in the design of future clinical trials.