GM-CSF as a therapeutic target in inflammatory diseases

An in vitro comparison of human corneal epithelial cell activity and inflammatory response on differently designed ocular amniotic membranes and a clinical case study

Amniotic membrane (AM) is a naturally derived biomaterial with biological and mechanical properties important to Ophthalmology. The epithelial side of the AM promotes epithelialization, while the stromal side regulates inflammation. However, not all AMs are equal. AMs undergo different processing with resultant changes in cellular content and structure. This study evaluates the effects of sidedness and processing on human corneal epithelial cell (HCEC) activity, the effect of processing on HCEC inflammatory response, and then a case study is presented. Three differently processed, commercially available ocular AMs were selected: (1) Biovance®3L Ocular, a decellularized, dehydrated human AM (DDHAM), (2) AMBIO2®, a dehydrated human AM (DHAM), and (3) AmnioGraft®, a cryopreserved human AM (CHAM). HCECs were seeded onto the AMs and incubated for 1, 4 and 7 days. Cell adhesion and viability were evaluated using alamarBlue assay. HCEC migration was evaluated using a scratch wound assay. An inflammatory response was induced by TNF-α treatment. The effect of AM on the expression of pro-inflammatory genes in HCECs was compared using quantitative polymerase chain reaction (qPCR). Staining confirmed complete decellularization and the absence of nuclei in DDHAM. HCEC activity was best supported on the stromal side of DDHAM. Under inflammatory stimulation, DDHAM promoted a higher initial inflammatory response with a declining trend across time. Clinically, DDHAM was used to successfully treat anterior basement membrane dystrophy. Compared with DHAM and CHAM, DDHAM had significant positive effects on the cellular activities of HCECs in vitro, which may suggest greater ocular cell compatibility in vivo.

An Update on the Emerging Role of Wnt/β-catenin, SYK, PI3K/AKT, and GM-CSF Signaling Pathways in Rheumatoid Arthritis

Rheumatoid arthritis is an untreatable autoimmune disorder. The disease is accompanied by joint impairment and anomalies, which negatively affect the patient's quality of life and contribute to a decline in manpower. To diagnose and treat rheumatoid arthritis, it is crucial to understand the abnormal signaling pathways that contribute to the disease. This understanding will help develop new rheumatoid arthritis-related intervention targets. Over the last few decades, researchers have given more attention to rheumatoid arthritis. The current review seeks to provide a detailed summary of rheumatoid arthritis, highlighting the basic description of the disease, past occurrences, the study of epidemiology, risk elements, and the process of disease progression, as well as the key scientific development of the disease condition and multiple signaling pathways and enumerating the most current advancements in discovering new rheumatoid arthritis signaling pathways and rheumatoid arthritis inhibitors. This review emphasizes the anti-rheumatoid effects of these inhibitors [for the Wnt/β-catenin, Phosphoinositide 3-Kinases (PI3K/AKT), Spleen Tyrosine Kinase (SYK), and Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) signaling pathways], illustrating their mechanism of action through a literature search, current therapies, and novel drugs under pre-clinical and clinical trials.

Drug Discovery in Canine Pyometra Disease Identified by Text Mining and Microarray Data Analysis

Canine pyometra, which is accompanied by bacterial contamination of the dog uterus, is defined as a complex disease associated with the activation of several systems, including the immune system. This study uses text mining and microarray data analysis methods to discover some existing targeted gene drugs and expand potential new drug indications. Text mining ("canine pyometra") and microarray data analysis (GSE99877) were used to obtain a common set of genes. These genes and protein-protein interaction (PPI) networks were analyzed using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes. Then, the important genes clustered in the PPI network were selected for gene-drug interaction analysis to provide evidence for potential drug discovery. Through text mining and data analysis, we obtained 17,544 text mining genes (TMGs) and 399 differentially expressed genes (DEGs), respectively. There were 256 repeat genes between TMGs and DEGs, including 70 upregulated genes and 186 downregulated genes. Thirty-seven genes clustered in three significant gene modules. Eight of the 37 genes can target 23 existing drugs. In conclusion, the discovery of 8 immune response-related genes (BTK, CSF2RA, CSF2RB, ITGAL, NCF4, PLCG2, PTPRC, and TOP2A) targeting 23 existing drugs may expand the drug indications for pyometra-related diseases in dogs.

The emerging role of regulatory cell-based therapy in autoimmune disease

Autoimmune disease, caused by unwanted immune responses to self-antigens, affects millions of people each year and poses a great social and economic burden to individuals and communities. In the course of autoimmune disorders, including rheumatoid arthritis, systemic lupus erythematosus, type 1 diabetes mellitus, and multiple sclerosis, disturbances in the balance between the immune response against harmful agents and tolerance towards self-antigens lead to an immune response against self-tissues. In recent years, various regulatory immune cells have been identified. Disruptions in the quality, quantity, and function of these cells have been implicated in autoimmune disease development. Therefore, targeting or engineering these cells is a promising therapeutic for different autoimmune diseases. Regulatory T cells, regulatory B cells, regulatory dendritic cells, myeloid suppressor cells, and some subsets of innate lymphoid cells are arising as important players among this class of cells. Here, we review the roles of each suppressive cell type in the immune system during homeostasis and in the development of autoimmunity. Moreover, we discuss the current and future therapeutic potential of each one of these cell types for autoimmune diseases.

The monocyte-to-osteoclast transition in rheumatoid arthritis: Recent findings

Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation leading to joint destruction and deformity. The crucial role of osteoclasts in the bone erosion in RA has been demonstrated. Deregulated osteoclastogenesis which is affected by environmental factors including the inflammatory state, as well as genetic and epigenetic factors, is one of hallmarks of RA pathogenesis. An enhanced-monocyte-to-osteoclast transition plays an important role in osteoclast upregulation in RA because under specific stimuli, circulating monocytes might migrate to a specific location in the bones and fuse with each other to become mature multinucleated osteoclasts. To understand the mechanism of bone damage in RA and to develop novel treatments targeting osteoclast upregulation, it is important to clarify our understanding of the monocyte-to-osteoclast transition in RA. Several potential targets which inhibit both inflammation and osteoclastogenesis, as well as regulators that affect the monocyte-to-osteoclast transition have been revealed by recent studies. Here, we review the factors affecting osteoclastogenesis in RA, summarize the anti-osteoclastogenic effects of current RA treatments, and identify promising therapeutic targets relating to both inflammation and osteoclastogenesis.

An exploratory study investigating biomarkers associated with autoimmune pulmonary alveolar proteinosis (aPAP)

Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare lung disorder involving production of autoantibodies against endogenous granulocyte–macrophage colony-stimulating factor (GM-CSF). This study aimed to identify biomarkers that could be used to monitor for aPAP, particularly in patients treated with anti-GM-CSF antibodies. This was an exploratory, prospective, observational, single-center study. Pre-specified biomarkers were evaluated between baseline and Day 120 in serum/plasma, whole blood, sputum and exhaled breath condensate from patients with aPAP, healthy volunteers, and patients with chronic obstructive pulmonary disease (COPD) and asthma (not treated with anti-GM-CSF and with no evidence of aPAP). Pulmonary function tests were also performed. Overall, 144 individuals were enrolled (aPAP: n = 34, healthy volunteers: n = 24, COPD: n = 40 and asthma: n = 46). Plasma GM-CSF levels were lower, and Krebs von den Lungen 6 and GM-CSF autoantibody ranges were higher, in patients with aPAP compared with other populations. Surfactant proteins-A and -D, lactate dehydrogenase and carcinoembryonic antigen ranges partially or completely overlapped across populations. Most plasma biomarkers showed high sensitivity and specificity for detection of aPAP; GM-CSF and GM-CSF autoantibody concentrations demonstrated equivalent sensitivity for differentiating aPAP. In addition to characteristic GM-CSF autoantibodies, assessment of plasma GM-CSF may identify individuals at risk of developing aPAP.

Trial registration: EudraCT, 2012-003475-19. Registered 23 July 2012—https://eudract.ema.europa.eu/.

GM-CSF impairs erythropoiesis by disrupting erythroblastic island formation via macrophages

Anemia is a significant complication of chronic inflammation and may be related to dysregulated activities among erythroblastic island (EBI) macrophages. GM-CSF was reported to be upregulated and attracted as a therapeutic target in many inflammatory diseases. Among EBIs, we found that the GM-CSF receptor is preferentially and highly expressed among EBI macrophages but not among erythroblasts. GM-CSF treatment significantly decreases human EBI formation in vitro by decreasing the adhesion molecule expression of CD163. RNA-sequence analysis suggests that GM-CSF treatment impairs the supporting function of human EBI macrophages during erythropoiesis. GM-CSF treatment also polarizes human EBI macrophages from M2-like type to M1-like type. In addition, GM-CSF decreases mouse bone marrow (BM) erythroblasts as well as EBI macrophages, leading to a reduction in EBI numbers. In defining the molecular mechanism at work, we found that GM-CSF treatment significantly decreases the adhesion molecule expression of CD163 and Vcam1 in vivo. Importantly, GM-CSF treatment also decreases the phagocytosis rate of EBI macrophages in mouse BM as well as decreases the expression of the engulfment-related molecules Mertk, Axl, and Timd4. In addition, GM-CSF treatment polarizes mouse BM EBI macrophages from M2-like type to M1-like type. Thus, we document that GM-CSF impairs EBI formation in mice and humans. Our findings support that targeting GM-CSF or reprogramming EBI macrophages might be a novel strategy to treat anemia resulting from inflammatory diseases.

Neutrophil Homeostasis and Emergency Granulopoiesis: The Example of Systemic Juvenile Idiopathic Arthritis

Neutrophils are key pathogen exterminators of the innate immune system endowed with oxidative and non-oxidative defense mechanisms. More recently, a more complex role for neutrophils as decision shaping cells that instruct other leukocytes to fine-tune innate and adaptive immune responses has come into view. Under homeostatic conditions, neutrophils are short-lived cells that are continuously released from the bone marrow. Their development starts with undifferentiated hematopoietic stem cells that pass through different immature subtypes to eventually become fully equipped, mature neutrophils capable of launching fast and robust immune responses. During severe (systemic) inflammation, there is an increased need for neutrophils. The hematopoietic system rapidly adapts to this increased demand by switching from steady-state blood cell production to emergency granulopoiesis. During emergency granulopoiesis, the de novo production of neutrophils by the bone marrow and at extramedullary sites is augmented, while additional mature neutrophils are rapidly released from the marginated pools. Although neutrophils are indispensable for host protection against microorganisms, excessive activation causes tissue damage in neutrophil-rich diseases. Therefore, tight regulation of neutrophil homeostasis is imperative. In this review, we discuss the kinetics of neutrophil ontogenesis in homeostatic conditions and during emergency myelopoiesis and provide an overview of the different molecular players involved in this regulation. We substantiate this review with the example of an autoinflammatory disease, i.e. systemic juvenile idiopathic arthritis.

Chronic pharmacological antagonism of the GM-CSF receptor in mice does not replicate the pulmonary alveolar proteinosis phenotype but does alter lung surfactant turnover

Granulocyte macrophage colony stimulating factor (GM-CSF) is a key participant in, and a clinical target for, the treatment of inflammatory diseases including rheumatoid arthritis (RA). Therapeutic inhibition of GM-CSF signalling using monoclonal antibodies to the α-subunit of the GM-CSF receptor (GMCSFRα) has shown clear benefit in patients with RA, giant cell arteritis (GCAs) and some efficacy in severe SARS-CoV-2 infection. However, GM-CSF autoantibodies are associated with the development of pulmonary alveolar proteinosis (PAP), a rare lung disease characterised by alveolar macrophage (AM) dysfunction and the accumulation of surfactant lipids. We assessed how the anti-GMCSFRα approach might impact surfactant turnover in the airway. Female C57BL/6J mice received a mouse-GMCSFRα blocking antibody (CAM-3003) twice per week for up to 24 weeks. A parallel, comparator cohort of the mouse PAP model, GM-CSF receptor β subunit (GMCSFRβ) knock-out (KO), was maintained up to 16 weeks. We assessed lung tissue histopathology alongside lung phosphatidylcholine (PC) metabolism using stable isotope lipidomics. GMCSFRβ KO mice reproduced the histopathological and biochemical features of PAP, accumulating surfactant PC in both broncho-alveolar lavage fluid (BALF) and lavaged lung tissue. The incorporation pattern of methyl-D9-choline showed impaired catabolism and not enhanced synthesis. In contrast, chronic supra-pharmacological CAM-3003 exposure (100 mg/kg) over 24 weeks did not elicit a histopathological PAP phenotype despite some changes in lung PC catabolism. Lack of significant impairment of AM catabolic function supports clinical observations that therapeutic antibodies to this pathway have not been associated with PAP in clinical trials.

Molecular Level Insights Into the Structural and Dynamic Factors Driving Cytokine Function

Cytokines are key mediators of cellular communication and regulators of biological advents. The timing, quantity and localization of cytokines are key features in producing specific biological outcomes, and thus have been thoroughly studied and reviewed while continuing to be a focus of the cytokine biology community. Due to the complexity of cellular signaling and multitude of factors that can affect signaling outcomes, systemic level studies of cytokines are ongoing. Despite their small size, cytokines can exhibit structurally promiscuous and dynamic behavior that plays an equally important role in biological activity. In this review using case studies, we highlight the recent insight gained from observing cytokines through a molecular lens and how this may complement a system-level understanding of cytokine biology, explain diversity of downstream signaling events, and inform therapeutic and experimental development.

Identifying and managing CAR T-cell-mediated toxicities: on behalf of an Italian CAR-T multidisciplinary team

INTRODUCTION

Chimeric antigen receptor (CAR)-T-cell therapy is a new treatment for patients with hematologic malignancies in which other therapies have failed.

AREAS COVERED

The review provides an overview for recognizing and managing the most acute toxicities related to CAR-T cells.

EXPERT OPINION

The development of immune-mediated toxicities is a common challenge of CAR-T therapy. The mechanism that determines this toxicity is still unclear, although an unfavorable tumor microenvironment and a pro-inflammatory state put patients at risk. The monitoring, diagnosis, and treatment of post-CAR-T toxicities must be determined and based on international guidelines and internal clinical practice. It is urgent to identify biomarkers that can identify patients at greater risk of developing complications. The adoption of consistent grading criteria is necessary to improve toxicity management strategies continually. The first-line therapy consists of supportive care and treatment with tocilizumab or corticosteroids. An early start of cytokine blockade therapies could mitigate toxicity. The plan will include cytokine release prophylaxis, a risk-adapted treatment, prevention of on-target/off-tumor effect, and a switch on/off CAR-T approach.

Increased metformin dosage suppresses pro-inflammatory cytokine levels in systemic circulation and might contribute to its beneficial effects

Type 2 Diabetes Mellitus (T2DM) is a metabolic disorder, characterized by persistent elevation of blood glucose either due to insulin resistance or insulin insufficiency. Metformin is the recommended first choice of drug for the management of T2DM and is known to improve insulin sensitivity and prevents hyperglycemia by reducing chronic inflammation. T-helper type 1 (Th1) and type 17 (Th17) cells, are important pro-inflammatory CD4⁺ T cell subsets secreting TNF-α, and INF-γ (Th1), and interleukin 17 (Th17). These cytokines have been shown to play a crucial role in inflammation, insulin resistance, and the development of T2DM. Here, we explore the effect of different metformin dosages on pro-inflammatory cytokine (TNF-α, INF-γ, GM-CSF and IL-17) levels in systemic circulation among T2DM patients in Ghana, since inflammatory responses and cytokines play significant roles in the pathogenesis and progression of T2DM patients on metformin. Two hundred and nine (209) consenting T2DM patients receiving treatment at the Diabetic unit of the Komfo Anokye Teaching Hospital (KATH) in the Ashanti region of Ghana were recruited in a hospital-based cross-sectional study design. Blood samples were collected and serum obtained from each participant were analyzed for the concentrations of TNF-α, INF-γ, GM-CSF and IL-17 cytokine levels by solid-phase sandwich ELISA. We observed that participants on 3000 mg/day dose of metformin had significantly lower levels of TNF-α (p < .001) and IFN-γ (p = .014) compared to those on other dosages (1000 mg and 2000 mg/day). However, GM-CSF and IL-17 levels were not affected by increased metformin dosages. After adjusting for age, gender, dose and duration of metformin use, we observed that participants who took higher doses of metformin had significantly reduced levels of TNF-α (β = -0.0297, 95% CI = (-0.005 to -0.002) p < .001. Metformin dosage independently predicted reduced TNF-α levels with 14.4% variations in the metformin dosage levels. Increased metformin dosage suppresses TNF-α levels in systemic circulation and hence might contribute to its beneficial effects.

Prostaglandin F2α in vitro can affect basic inflammatory parameters of mesenchymal stem cells and slight modulating some of their immunomodulatory properties

In the last decade, mesenchymal stem cells (MSCs) have been gaining attention due their ability to influence the function of other cells as well as modulate the inflammatory response. This occurs via their immunomodulatory functions,  acting through direct cell-cell interaction or by releasing a broad spectrum of bioactive factors such as cytokines and growth factors. In addition, prostaglandins are arachidonic acid metabolites that play a key role in the generation and modulation of the inflammatory response. Among the bioactive prostaglandins, PGF_2α is able to stimulate cell proliferation as well as act to inhibit progenitor cell differentiation, but no information about this prostaglandin's action on the immunoregulatory function of MSCs has been reported. In this study we evaluate important aspects of the influence of PGF_2α analog (17-phenyl-trinor PGF_2α), which is a potent prostaglandin FP receptor agonist, on some mechanisms that control the main functions of MSCs. C3H10T1/2, a mesenchymal stem cell linage, was stimulated with PGF_2α under inflammatory conditions trigged by LPS in order to investigate PGF_2α inflammatory parameters as well as its ability to immunoregulate macrophages and lymphocytes. PGF_2α has the ability to increase proliferation tax without altering the cell viability of LPS-stimulated MSCs, while also diminishing the phosphorylation of NFκB transcription factor leading to attenuation of IL-1β and GM-CSF production. Additionally, MSC-s conditioned media from cells stimulated with PGF_2α was able to increase the lymphocytes' IL-10 production. Overall, this study implied that PGF_2α are able to modify some properties of MSCs.

Myeloid-derived suppressor cells promote epithelial ovarian cancer cell stemness by inducing the CSF2/p-STAT3 signalling pathway

Myeloid‐derived suppressor cells (MDSCs) are known to contribute to tumour immune evasion, and studies have verified that MDSCs can induce cancer stem cells (CSCs) and promote tumour immune evasion in breast cancers, cervical cancers and glioblastoma. However, the potential function of MDSCs in regulating CSCs in epithelial ovarian cancer (EOC) progression is unknown. Our results indicated that compared to nonmalignant ovarian patients, EOC patients showed a significantly increased proportion of MDSCs in the peripheral blood. In addition, MDSCs dramatically promoted tumour sphere formation, cell colony formation and CSC accumulation, and MDSCs enhanced the expression of the stemness biomarkers NANOG and c‐MYC in EOC cells during coculture. Moreover, the mechanisms by which MDSCs enhance EOC stemness were further explored, and 586 differentially expressed genes were found in EOC cells cocultured with or without MDSCs; during coculture, the expression level of colony‐stimulating factor 2 (CSF2) was significantly increased in EOC cells cocultured with MDSCs. Furthermore, the depletion of CSF2 in EOC cells was successfully performed, the promotive effects of MDSCs on EOC cell stemness could be markedly reversed by downregulating CSF2 expression, p‐STAT3 signalling pathway molecules were also altered, and the p‐STAT3 inhibitor could markedly reverse the promotive effects of MDSCs on EOC cell stemness. In addition, the CSF2 expression level was correlated with EOC clinical staging. Therefore, MDSCs enhance the stemness of EOC cells by inducing the CSF2/p‐STAT3 signalling pathway. Targeting MDSCs or CSF2 may be a reasonable strategy for enhancing the efficacy of conventional treatments.

Database

Gene expression data files are available in the GEO databases under the accession number(s) GSE145374.

Drug delivery to macrophages: A review of targeting drugs and drug carriers to macrophages for inflammatory diseases

Macrophages play a key role in defending against foreign pathogens, healing wounds, and regulating tissue homeostasis. Driving this versatility is their phenotypic plasticity, which enables macrophages to respond to subtle cues in tightly coordinated ways. However, when this coordination is disrupted, macrophages can aid the progression of numerous diseases, including cancer, cardiovascular disease, and autoimmune disease. The central link between these disorders is aberrant macrophage polarization, which misguides their functional programs, secretory products, and regulation of the surrounding tissue microenvironment. As a result of their important and deterministic roles in both health and disease, macrophages have gained considerable attention as targets for drug delivery. Here, we discuss the role of macrophages in the initiation and progression of various inflammatory diseases, summarize the leading drugs used to regulate macrophages, and review drug delivery systems designed to target macrophages. We emphasize strategies that are approved for clinical use or are poised for clinical investigation. Finally, we provide a prospectus of the future of macrophage-targeted drug delivery systems.

Unravelling the genetic basis of schizophrenia and bipolar disorder with GWAS: A systematic review

OBJECTIVES

To systematically review findings of GWAS in schizophrenia (SZ) and in bipolar disorder (BD); and to interpret findings, with a focus on identifying independent replications.

METHOD

PubMed search, selection and review of all independent GWAS in SZ or BD, published since March 2011, i.e. studies using non-overlapping samples within each article, between articles, and with those of the previous review (Li et al., 2012).

RESULTS

From the 22 GWAS included in this review, the genetic associations surviving standard GWAS-significance were for genetic markers in the regions of ACSL3/KCNE4, ADCY2, AMBRA1, ANK3, BRP44, DTL, FBLN1, HHAT, INTS7, LOC392301, LOC645434/NMBR, LOC729457, LRRFIP1, LSM1, MDM1, MHC, MIR2113/POU3F2, NDST3, NKAPL, ODZ4, PGBD1, RENBP, TRANK1, TSPAN18, TWIST2, UGT1A1/HJURP, WHSC1L1/FGFR1 and ZKSCAN4. All genes implicated across both reviews are discussed in terms of their function and implication in neuropsychiatry.

CONCLUSION

Taking all GWAS to date into account, AMBRA1, ANK3, ARNTL, CDH13, EFHD1 (albeit with different alleles), MHC, PLXNA2 and UGT1A1 have been implicated in either disorder in at least two reportedly non-overlapping samples. Additionally, evidence for a SZ/BD common genetic basis is most strongly supported by the implication of ANK3, NDST3, and PLXNA2.

Roles of GM-CSF in the Pathogenesis of Autoimmune Diseases: An Update

Granulocyte-macrophage colony-stimulating factor (GM-CSF) was first described as a growth factor that induces the differentiation and proliferation of myeloid progenitors in the bone marrow. GM-CSF also has an important cytokine effect in chronic inflammatory diseases by stimulating the activation and migration of myeloid cells to inflammation sites, promoting survival of target cells and stimulating the renewal of effector granulocytes and macrophages. Because of these pro-cellular effects, an imbalance in GM-CSF production/signaling may lead to harmful inflammatory conditions. In this context, GM-CSF has a pathogenic role in autoimmune diseases that are dependent on cellular immune responses such as multiple sclerosis (MS) and rheumatoid arthritis (RA). Conversely, a protective role has also been described in other autoimmune diseases where humoral responses are detrimental such as myasthenia gravis (MG), Hashimoto's thyroiditis (HT), inflammatory bowel disease (IBD), and systemic lupus erythematosus (SLE). In this review, we aimed for a comprehensive analysis of literature data on the multiple roles of GM-CSF in autoimmue diseases and possible therapeutic strategies that target GM-CSF production.

High levels of circulating GM-CSF+CD4+ T cells are predictive of poor outcomes in sepsis patients: a prospective cohort study

Granulocyte colony-stimulating factor (GM-CSF), produced by CD4⁺ T cells, has recently been implicated in the pathogenesis of inflammatory diseases, such as multiple sclerosis and juvenile arthritis. However, the role of GM-CSF-producing CD4⁺ T cells in sepsis remains unknown. This study reports peripheral changes in GM-CSF-producing CD4⁺ T cells in septic patients and the possible underlying mechanism by which GM-CSF influences the outcome of sepsis. Forty-three septic patients, 20 SIRS patients, and 20 healthy controls were enrolled in this study and followed for 28 days to assess mortality. We measured the peripheral frequency of GM-CSF⁺CD4⁺ T cells and recorded their associated relationship with disease progression. Our data demonstrated that peripheral GM-CSF-producing CD4⁺ T cells were significantly higher in septic patients than in both SIRS patients and healthy controls. These cells exhibit a memory phenotype and impaired IFN-γ-secreting capacity in sepsis patients. Using a receiver operating curve analysis with 8.01% as a cut-off point, the percentage of GM-CSF⁺CD4⁺ T cells could predict the outcome of septic patients^. Combined with the increase in GM-CSF-producing CD4⁺ T cells, inflammatory cytokines IL-1β and IL-6 were also upregulated. Using an in vitro neutrophil model, we found that GM-CSF inhibited C3aR expression, while inducing IL-8 production. Furthermore, this effect was transferrable in plasma from sepsis patients and was attenuated by inhibition of GM-CSF using an anti-GM-CSF antibody. These results indicate that GM-CSF-producing CD4⁺ T cells may serve as a marker of sepsis severity. Thus, targeting GM-CSF overproduction may benefit sepsis patients.

Regulation of Lymphatic GM-CSF Expression by the E3 Ubiquitin Ligase Cbl-b

Genome-wide association studies as well as lymphatic expression analyses have linked both Cbl-b and GM-CSF to human multiple sclerosis as well as other autoimmune diseases. Both Cbl-b and GM-CSF have been shown to play a prominent role in the development of murine encephalomyelitis; however, no functional connection between the two has yet been established. In this study, we show that Cblb knockout mice demonstrated significantly exacerbated severity of experimental autoimmune encephalomyelitis (EAE), augmented T cell infiltration into the central nervous system (CNS) and strongly increased production of GM-CSF in T cells in vitro and in vivo.GM-CSF neutralization demonstrated that the increased susceptibility of Cblb^−/− mice to EAE was dependent on GM-CSF. Mechanistically, p50 binding to the GM-CSF promoter and the IL-3/GM-CSF enhancer element “CNSa” was strongly increased in nuclear extracts from Cbl-b-deficient T cells. This study suggests that Cbl-b limits autoimmunity by preventing the pathogenic effects of GM-CSF overproduction in T cells.

The mechanism of GM-CSF inhibition by human GM-CSF auto-antibodies suggests novel therapeutic opportunities

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor that can stimulate a variety of cells, but its overexpression leads to excessive production and activation of granulocytes and macrophages with many pathogenic effects. This cytokine is a therapeutic target in inflammatory diseases, and several anti-GM-CSF antibodies have advanced to Phase 2 clinical trials in patients with such diseases, e.g., rheumatoid arthritis. GM-CSF is also an essential factor in preventing pulmonary alveolar proteinosis (PAP), a disease associated with GM-CSF malfunction arising most typically through the presence of GM-CSF neutralizing auto-antibodies. Understanding the mechanism of action for neutralizing antibodies that target GM-CSF is important for improving their specificity and affinity as therapeutics and, conversely, in devising strategies to reduce the effects of GM-CSF auto-antibodies in PAP. We have solved the crystal structures of human GM-CSF bound to antigen-binding fragments of two neutralizing antibodies, the human auto-antibody F1 and the mouse monoclonal antibody 4D4. Coordinates and structure factors of the crystal structures of the GM-CSF:F1 Fab and the GM-CSF:4D4 Fab complexes have been deposited in the RCSB Protein Data Bank under the accession numbers 6BFQ and 6BFS, respectively. The structures show that these antibodies bind to mutually exclusive epitopes on GM-CSF; however, both prevent the cytokine from interacting with its alpha receptor subunit and hence prevent receptor activation. Importantly, identification of the F1 epitope together with functional analyses highlighted modifications to GM-CSF that would abolish auto-antibody recognition whilst retaining GM-CSF function. These results provide a framework for developing novel GM-CSF molecules for PAP treatment and for optimizing current anti-GM-CSF antibodies for use in treating inflammatory disorders.

Evaluation of effectiveness of granulocyte-macrophage colony-stimulating factor therapy to cancer patients after chemotherapy: a meta-analysis

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.

Hydrogen protects lung from hypoxia/re-oxygenation injury by reducing hydroxyl radical production and inhibiting inflammatory responses

Here we investigated whether hydrogen can protect the lung from chronic injury induced by hypoxia/re-oxygenation (H/R). We developed a mouse model in which H/R exposure triggered clinically typical lung injury, involving increased alveolar wall thickening, infiltration by neutrophils, consolidation, alveolar hemorrhage, increased levels of inflammatory factors and recruitment of M1 macrophages. All these processes were attenuated in the presence of H₂. We found that H/R-induced injury in our mouse model was associated with production of hydroxyl radicals as well as increased levels of colony-stimulating factors and circulating leukocytes. H₂ attenuated H/R-induced production of hydroxyl radicals, up-regulation of colony-stimulating factors, and recruitment of neutrophils and M1 macrophages to lung tissues. However, H₂ did not substantially affect the H/R-induced increase in erythropoietin or pulmonary artery remodeling. Our results suggest that H₂ ameliorates H/R-induced lung injury by inhibiting hydroxyl radical production and inflammation in lungs. It may also prevent colony-stimulating factors from mobilizing progenitors in response to H/R-induced injury.

Astrocyte disruption of neurovascular communication is linked to cortical damage in an animal model of multiple sclerosis

To elucidate mechanisms contributing to cortical pathology in multiple sclerosis (MS), we investigated neurovascular aberrations, in particular the association of astrocytes with cortical neurons and blood vessels, in mice induced with experimental autoimmune encephalomyelitis (EAE). Blood-brain barrier (BBB) dysfunction was evident by leakage of the tracer sodium fluorescein, along with reduced expression of claudin-5 by endothelial cells and desmin by pericytes. Immunohistological and ultrastructural analyses revealed detachment of the astroglial cell bodies from the blood vessels and loss of their connections with both the blood vessels and the neuronal synapses. Furthermore, examination of individual astrocytic processes at cortical layer IV, where well-defined neuronal columns (barrels) are linked to functional properties, revealed loss of astrocytic confinement to the functional neuronal boundaries. Thus, in contrast to the highly modulated patches of astrocyte processes in naïve mice overlapping the barrel cores, in EAE-mice process distribution was uniform ignoring the barrel boundaries. These aberrations are attributed to the surrounding inflammation, indicated by T-cells presence in the cortex as well as in the subcortical white matter and the meninges. Immunomodulatory treatment with glatiramer acetate partially abrogated the neurovascular damage. These combined findings indicate that under inflammatory conditions, activated perivascular astrocytes fail in neuro-hemodynamic coupling, resulting in obstructed cross-talk between the blood vessels and the neurons. We propose that loss of cortical astrocytic regulation and fine-tuning between the blood supply and the neuronal needs contributes to the neurological impairment and cognitive decline occurring in EAE/MS as well as to the disease progression.

Increased Frequency of Peripheral B and T Cells Expressing Granulocyte Monocyte Colony-Stimulating Factor in Rheumatoid Arthritis Patients

Objectives

Granulocyte monocyte colony-stimulating factor (GM-CSF) is currently considered a crucial inflammatory mediator and a novel therapeutic target in rheumatoid arthritis (RA), despite the fact that its precise cellular sources remain uncertain. We studied the expression of GM-CSF in peripheral lymphocytes from RA patients and its change with antirheumatic therapies.

Methods

Intracellular GM-CSF expression was assessed by flow cytometry in stimulated peripheral B (CD19+) and T (CD3+) cells from RA patients (n = 40), disease (n = 31 including osteoarthritis n = 15, psoriatic arthritis n = 10, and systemic rheumatic diseases n = 6) and healthy (n = 16) controls. The phenotype of GM-CSF+ B cells was assessed as well as longitudinal changes in GM-CSF+ lymphocytes during methotrexate (MTX, n = 10) or anti-tumor necrosis factor (anti-TNF, n = 10) therapy.

Results

Among untreated RA patients with active disease (Disease Activity Score 28-C-reactive protein = 5.6 ± 0.89) an expanded population of peripheral GM-CSF+ B (4.1 ± 2.2%) and T (3.4 ± 1.6%) cells was detected compared with both disease (1.7 ± 0.9%, p < 0.0001 and 1.7 ± 1.3%, p < 0.0001, respectively) and healthy (0.3 ± 0.2%, p < 0.0001 and 0.6 ± 0.6%, p < 0.0001) controls. RA GM-CSF+ B cells displayed more commonly a plasmablast or transitional phenotype (37.12 ± 18.34% vs. 14.26 ± 9.46%, p = 0.001 and 30.49 ± 15.04% vs. 2.45 ± 1.84%, p < 0.0001, respectively) and less a memory phenotype (21.46 ± 20.71% vs. 66.99 ± 16.63%, p < 0.0001) compared to GM-CSF- cells. GM-CSF expression in RA patients did not correlate to disease duration, activity or serological status. Anti-TNF treatment led to a statistically significant decrease in GM-CSF+ B and T cells while MTX had no significant effect.

Discussion

This is the first study showing an expanded population of GM-CSF+ B and T lymphocytes in patients with active RA which declined after anti-TNF therapy.

Cytokine distribution in mothers and breastfed children after omega-3 LCPUFAs supplementation during the last trimester of pregnancy and the lactation period: A randomized, controlled trial

OBJECTIVE

To determine whether maternal diet supplementation with omega-3 long chain polyunsaturated fatty acids (omega-3 LC-PUFAs) during the last trimester of pregnancy and the breastfeeding period influences the levels of inflammatory cytokines in mother and infants.

MATERIAL AND METHOD

This registered, double-blind randomized study included 46 pregnant women, who were randomly allocated to either an experimental group receiving 400mL/day of a fish oil-enriched dairy drink [320mg docosahexaenoic acid (DHA) + 72mg eicoapentaenoic acid] (FO group, n = 24) or to a control group receiving 400mL/day of a non-supplemented dairy drink (CT group, n = 22), from week 28 of pregnancy until the fourth month of lactation. During the study, maternal dietary patterns were monitored by a nutritionist, who encouraged compliance with current recommendations of fatty acids intake. DHA concentrations and cytokine levels (GM-CSF, IL-2, IL-4, IL-6, IL-10, INF-γ and TNF-α) were measured in maternal plasma at the moment of recruitment and in maternal (n = 46) and infant (n = 46) plasma at birth and 2.5 months after birth.

RESULTS

Maternal plasmatic IL-4 levels were higher in FO than in CT subjects (p = 0.009). Additionally, a tendency was observed to higher IL-10 and IL-2 in the FO group. Plasmatic IL-6 however, was higher in CT mothers (p = 0.001). TNF-α was higher in CT infants at birth and 2.5 months after birth (p = 0.005). An analysis of possible relationships between DHA and the concentrations of different cytokines revealed negative correlation between maternal plasmatic IL-6 and DHA (higher plasmatic DHA corresponded to lower IL-6).

CONCLUSIONS

Maternal dietary omega-3 LC-PUFAs supplementation during critical periods like pregnancy, lactation and early newborn development may influence the levels of certain inflammatory cytokines, reducing pro-inflammatory cytokines and promoting an anti-inflammatory "environment".

Relationship between serum inflammatory markers and vascular function in a cohort of adolescents with type 1 diabetes

OBJECTIVE

The contribution of inflammation to endothelial/vascular dysfunction in early Type I Diabetes (T1D) is not well understood. The objective of this study was to examine the interaction between systemic inflammation and vascular function in adolescent's with and without-T1D.

METHODS

51 subjects from our observational cohort of adolescents with T1D (JDRF-CCTN), and 59 healthy controls (HC) were studied. Serum cytokines-chemokines were quantified using Human 41-Plex Array, and vascular function was measured by Flow Mediated Dilatation (FMD), Pulse Wave Velocity (PWV) and Blood Pressure (BP). Factor Analysis was used to identify pro- and anti-inflammatory cytokine-chemokine factors, which were then correlated with vascular outcomes.

RESULTS

Three pro-inflammatory factors were identified in HC and three in TID, and a single anti-inflammatory factor in both groups. In HC there was a positive correlation (r=0.33; p=0.01) between control proinflammatory Factor 1 and systolic BP and a negative correlation between control proinflammatory Factor 3(r=-0.29; p=0.02) and diastolic BP. Control proinflammatory Factor 2 correlated positively with PWV. In TID subjects, no correlations were found between any of the pro-inflammatory factors and the vascular measurements. No correlations were found between the anti-inflammatory factors and BP, FMD and PWV in either HC or T1D. Levels of pro-inflammatory analytes, EGF, GRO, PDGF-BB, PDGF-AA and sCD40L were significantly higher in T1D.

CONCLUSIONS

The cytokine-chemokine signature in early T1D, prior to the development of arterial disease, is significantly different from that seen in healthy controls. This may be relevant to pathophysiology, determining risk and identifying target cytokines-chemokines for intervention in T1D.

Molecular mechanisms regulating secretory organelles and endosomes in neutrophils and their implications for inflammation

Neutrophils constitute the first line of cellular defense against invading microorganisms and modulate the subsequent innate and adaptive immune responses. In order to execute a rapid and precise response to infections, neutrophils rely on preformed effector molecules stored in a variety of intracellular granules. Neutrophil granules contain microbicidal factors, the membrane-bound components of the respiratory burst oxidase, membrane-bound adhesion molecules, and receptors that facilitate the execution of all neutrophil functions including adhesion, transmigration, phagocytosis, degranulation, and neutrophil extracellular trap formation. The rapid mobilization of intracellular organelles is regulated by vesicular trafficking mechanisms controlled by effector molecules that include small GTPases and their interacting proteins. In this review, we focus on recent discoveries of mechanistic processes that are at center stage of the regulation of neutrophil function, highlighting the discrete and selective pathways controlled by trafficking modulators. In particular, we describe novel pathways controlled by the Rab27a effectors JFC1 and Munc13-4 in the regulation of degranulation, reactive oxygen species and neutrophil extracellular trap production, and endolysosomal signaling. Finally, we discuss the importance of understanding these molecular mechanisms in order to design novel approaches to modulate neutrophil-mediated inflammatory processes in a targeted fashion.

Identification of genes dysregulated by elevation of microRNA-210 levels in human trophoblasts cell line, Swan 71

PROBLEM

Preeclampsia is a serious pregnancy disorder characterized by gestational hypertension and proteinuria. miR-210 is significantly overexpressed in the placentas of preeclampsia patients.

METHOD OF STUDY

Swan 71 cells, first-trimester human trophoblastic cell line, were transfected with hsa-miR-210-3p oligonucleotides by electroporation. Altered transcriptome was analyzed using microarray technique. Differentially expressed genes (DEGs) were clustered into Gene Ontology annotation biological processes. The extent of physical interaction between miR-210 and IGFBP3 mRNA was assessed via ribonucleoprotein immunoprecipitation.

RESULTS

Microarray analysis showed 408 DEGs by elevated levels of miR-210 in Swan 71 cells. These genes were enriched in several biological processes involved in the pathogenesis of preeclampsia. IGFBP3, a gene associated with preeclampsia pathophysiology, was validated as a target gene of miR-210.

CONCLUSION

We have demonstrated that elevated miR-210 levels in human trophoblast alter the expression profile of known preeclampsia-associated genes, and of gene targets involved in various biological processes essential to preeclampsia progression.

Rheumatoid arthritis: Recent advances on its etiology, role of cytokines and pharmacotherapy

An autoimmune disease is defined as a clinical syndrome resulted from an instigation of both T cell and B cell or individually, in the absence of any present infection or any sort of distinguishable cause. Clonal deletion of auto reactive cells remains the central canon of immunology for decades, keeping the role of T cell and B cell aside, which are actually the guards to recognize the entry of foreign body. According to NIH, 23.5 million Americans are all together affected by these diseases. They are rare, but with the exception of RA. Rheumatoid arthritis is chronic and systemic autoimmune response to the multiple joints with unknown ethology, progressive disability, systemic complications, early death and high socioeconomic costs. Its ancient disease with an old history found in North American tribes since 1500 BCE, but its etiology is yet to be explored. Current conventional and biological therapies used for RA are not fulfilling the need of the patients but give only partial responses. There is a lack of consistent and liable biomarkers of prognosis therapeutic response, and toxicity. Rheumatoid arthritis is characterized by hyperplasic synovium, production of cytokines, chemokines, autoantibodies like rheumatoid factor (RF) and anticitrullinated protein antibody (ACPA), osteoclastogensis, angiogenesis and systemic consequences like cardiovascular, pulmonary, psychological, and skeletal disorders. Cytokines, a diverse group of polypeptides, play critical role in the pathogenesis of RA. Their involvement in autoimmune diseases is a rapidly growing area of biological and clinical research. Among the proinflammatory cytokines, IL-1α/β and TNF-α trigger the intracellular molecular signalling pathway responsible for the pathogenesis of RA that leads to the activation of mesenchymal cell, recruitment of innate and adaptive immune system cells, activation of synoviocytes which in term activates various mediators including tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6) and interleukin-8 (IL-8), resulting in inflamed synovium, increase angiogenesis and decrease lymphangiogensis. Their current pharmacotherapy should focus on their three phases of progression i.e. prearthritis phase, transition phase and clinical phase. In this way we will be able to find a way to keep the balance between the pro and anti-inflammatory cytokines that is believe to be the dogma of pathogenesis of RA. For this we need to explore new agents, whether from synthetic or natural source to find the answers for unresolved etiology of autoimmune diseases and to provide a quality of life to the patients suffering from these diseases specifically RA.

NADPH oxidase NOX2 mediates TLR2/6-dependent release of GM-CSF from endothelial cells

NADPH oxidase-generated reactive oxygen species (ROS) from immune cells are well known to be important for pathogen killing in response to TLR ligands. Here, we investigated a new aspect of NADPH oxidase in the TLR2/6-induced release of the immunologically relevant GM-CSF by endothelial cells. Stimulation of human endothelial cells with TLR2/6 agonist, MALP-2 (macrophage-activating lipopeptide of 2 kDa), induced NADPH oxidase activation and ROS formation. Inhibition by ROS scavengers and NADPH oxidase inhibitors blocked MALP-2-induced GM-CSF release. NADPH oxidase activators or ROS donors alone did not result in GM-CSF secretion; however, additional superoxide supply augmented MALP-2-induced GM-CSF secretion and restored GM-CSF levels after NADPH oxidase inhibition. MALP-2-dependent NF-ĸB activation was suppressed by NADPH oxidase inhibition, and inhibition of NF-κB completely blunted MALP-2-induced GM-CSF release. Vascular explants from mice that were deficient for the NADPH oxidase subunit p47 ^phox showed diminished intimal superoxide production and GM-CSF release after ex vivo stimulation with MALP-2. Moreover, an increase in circulating progenitor cells after MALP-2 injection was completely abolished in p47^phox-knockout mice. Finally, MALP-2 stimulation increased mRNA expression of the major subunit NADPH oxidase, (Nox)2, in endothelial cells, and Nox2 inhibition prevented MALP-2-induced GM-CSF release. Our findings identify a Nox2-containing NADPH oxidase as a crucial regulator of the immunologic important growth factor GM-CSF after TLR2/6 stimulation in endothelial cells.-Schuett, J., Schuett, H., Oberoi, R., Koch, A.-K., Pretzer, S., Luchtefeld, M., Schieffer, B., Grote, K. NADPH oxidase NOX2 mediates TLR2/6-dependent release of GM-CSF from endothelial cells.

Innate lymphoid cells in autoimmunity: emerging regulators in rheumatic diseases

Innate lymphoid cells (ILCs) are important in the regulation of barrier homeostasis. These cells do not express T cell receptors but share many functional similarities with T helper cells and cytotoxic CD8⁺ T lymphocytes. ILCs are divided into three groups, namely group 1 ILCs, group 2 ILCs and group 3 ILCs, based on the transcription factors they depend on for their development and function, and the cytokines they produce. Emerging data indicate that ILCs not only have protective functions but can also have detrimental effects when dysregulated, leading to chronic inflammation and autoimmune diseases, including asthma, inflammatory bowel disease, graft-versus-host disease, psoriasis, rheumatoid arthritis and atopic dermatitis. Elucidation of the cytokine pathways involved in various autoimmune diseases - and the identification of ILCs as potent producers of these cytokines - points towards a potential role for these cellular players in the pathophysiology of these diseases. In this Review we discuss the current knowledge of the role of ILCs in the pathogenesis of rheumatic and other autoimmune diseases.

Are Modic changes associated with intervertebral disc cytokine profiles?

BACKGROUND CONTEXT

Degenerative changes including Modic changes (MCs) are commonly observed in patients with chronic low back pain. Although intervertebral disc (IVD) cytokine expression has been shown to be associated with low back pain, the cytokine profile for degenerative IVD with and without MC has not been compared.

PURPOSE

This study aimed to evaluate the potential association between IVD cytokine expression and MCs.

STUDY DESIGN

A laboratory study was carried out.

METHODS

The IVD tissue samples from 10 patients with type II MCs and10 patients without MCs who underwent an anterior lumbar interbody and fusion for significant low back pain were collected. The expression levels of 42 cytokines were determined using a RayBio Human Cytokine Antibody Array 3 (RayBiotech Inc, Norcross, GA, USA) and the results were verified with enzyme-linked immunosorbent assay (ELISA).

RESULTS

The cytokine array demonstrated a statistically significant increase in the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) (p=.001) and epithelial-derived neutrophil-activating peptide 78 (ENA-78) (p=.04), and a trend toward an increase in interleukin-1β (IL-1β) (p=.12) and tumor necrosis factor-α (TNF-α) (p=.22) in IVDs associated with type II MCs. These results were validated with ELISA which demonstrated a 3.85-fold increase in the GM-CSF level between IVDs with type II MCs compared with those without MCs (p=.03). Similarly there was a significant increase in the level of both ENA-78 (3.68-fold, p=.02) and IL-1β (2.11-fold, p=.01) in IVDs with type II MCs. Lastly, there was a trend (p=.07) toward an increase in TNF-α in IVDs with type II MCs (4.4-fold).

CONCLUSION

Intervertebral discs with type II MCs demonstrate a significant increase in IL-1β, GM-CSF, and ENA-78, and there is a trend toward an increase in TNF-α. These results further strengthen the association between MCs and low back pain.

Rheumatoid Arthritis Was Negatively Associated with Alzheimer's Disease: A Population-Based Case-Control Study

Some of the prior literature investigated the potential association between rheumatoid arthritis (RA) and Alzheimer's disease (AD) because these two diseases may share similar inflammatory mechanisms. Nevertheless, to date, findings of the previous literature are still controversial, and some methodological limitations were observed in those studies. The aim of this case-control study was to investigate the relationship between prior RA and AD using a large population-based dataset. This study used the Taiwan Longitudinal Health Insurance Database 2005. We included 2271 patients with AD who had received prescriptions for acetylcholinesterase inhibitors (AChEIs) as cases and 6813 patients without AD as controls in this study. In addition, we performed a conditional logistic regression to examine the odds ratio (OR) and 95% confidence interval (CI) for prior RA between cases and controls. The study found that 330 (3.63%) of the total sampled patients had an RA diagnosis before the index date. Additionally, prior RA was found in 60 (2.64%) cases and in 270 (3.96%) controls. The conditional logistic regression analysis showed that the crude OR of prior RA for cases was 0.66 (95% confidence interval (CI): 0.49~0.87) compared to controls. After adjusting for patients' geographic location, urbanization level, and comorbidities, the adjusted OR of prior RA for patients with AD was 0.73 (95% CI: 0.55~0.98) compared to those without AD. We concluded that there was an inverse association between prior RA and AD even after adjusting for potential confounders.

A novel cancer vaccine with the ability to simultaneously produce anti-PD-1 antibody and GM-CSF in cancer cells and enhance Th1-biased antitumor immunity

Tumor escape from immune-mediated destruction has been associated with immunosuppressive mechanisms that inhibit T-cell activation. A promising strategy for cancer immunotherapy is to disrupt key pathways regulating immune tolerance, such as program death-1 (PD-1/PD-L1) pathway in the tumor environment. However, the determinants of response to anti-PD-1 monoclonal antibodies (mAbs) treatment remain incompletely understood. In murine models, PD-1 blockade alone fails to induce effective immune responses to poorly immunogenic tumors, but is successful when combined with additional interventions, such as cancer vaccines. Novel cancer vaccines combined with antibody may offer promising control of cancer development and progression. In this investigation, we generated a novel tumor cell vaccine simultaneously expressing anti-PD-1 mAbs and granulocyte-macrophage colony stimulating factor (GM-CSF) in CT26 colon cancer and B16-F10 melanoma. The antitumor effect of the vaccine was verified by therapeutic and adoptive animal experiments in vivo. The antitumor mechanism was analyzed using Flow cytometry, Elispot and in vivo intervention approaches. The results showed that tumor cell vaccine secreting PD-1 neutralizing antibodies and GM-CSF induced remarkable antitumor immune effects and prolonged the survival of tumor-bearing animals compared with animals treated with either PD-1 mAbs or GM-CSF alone. Antitumor effects and prolonged survival correlated with strong antigen-specific T-cell responses by analyzing CD11c⁺CD86⁺ DC, CD11b⁺F4/80⁺ MΦ cells, increased ratio of Teff/Treg in the tumor microenvironment, and higher secretion levels of Th1 proinflammatory cytokines in serum. Furthermore, the results of ELISPOT and in vivo blocking strategies further confirmed that the antitumor immune response is acquired by CD4 and CD8 T immune responses, primarily dependent on CD4 Th1 immune response, not NK innate immune response. The combination of PD-1 blockade with GM-CSF secretion potency creates a novel tumor cell vaccine immunotherapy, affording significantly improved antitumor responses by releasing the state of immunosuppressive microenvironment and augmenting the tumor-reactive T-cell responses.

Mechanisms of Acute Toxicity in NKG2D Chimeric Antigen Receptor T Cell-Treated Mice

Targeting cancer through the use of effector T cells bearing chimeric Ag receptors (CARs) leads to elimination of tumors in animals and patients, but recognition of normal cells or excessive activation can result in significant toxicity and even death. CAR T cells based on modified NKG2D receptors are effective against many types of tumors, and their efficacy is mediated through direct cytotoxicity and cytokine production. Under certain conditions, their ligands can be expressed on nontumor cells, so a better understanding of the potential off-tumor activity of these NKG2D CAR T cells is needed. Injection of very high numbers of activated T cells expressing CARs based on murine NKG2D or DNAM1 resulted in increased serum cytokines (IFN-γ, IL-6, and MCP-1) and acute toxicity similar to cytokine release syndrome. Acute toxicity required two key effector molecules in CAR T cells-perforin and GM-CSF. Host immune cells also contributed to this toxicity, and mice with severe immune cell defects remained healthy at the highest CAR T cell dose. These data demonstrate that specific CAR T cell effector mechanisms and the host immune system are required for this cytokine release-like syndrome in murine models.

IL-25 attenuates rheumatoid arthritis through suppression of Th17 immune responses in an IL-13-dependent manner

IL-25, a new member of the IL-17 cytokine family, is involved in type 2 immunity initiation and has been associated with the pathogenesis of rheumatoid arthritis (RA). However, its exact role remains unclear. Here, we aimed to analyse IL-25 expression in the serum and synovial fluid of RA patients and evaluated the correlations between serum IL-25 levels, clinical and laboratory values and inflammation cytokines. Additionally, we investigated whether IL-25 can suppress Th1/Th17 responses involved in RA pathogenesis. We further determined whether IL-25 can alleviate collagen-induced arthritis (CIA) development in mice and the underlying mechanisms using in vitro and in vivo experiments. Our results showed that IL-25 was upregulated in the serum and synovial fluid of RA patients. Increased serum IL-25 levels were associated with disease severity and inflammatory response in RA patients. Furthermore, IL-25 inhibited CD4⁺ T-cell activation and differentiation into Th17 cells, without affecting Th1 cells in human RA and CIA models. Administration of IL-25 could attenuate CIA development by Th17 suppression in an IL-13-dependent manner. Our findings indicate that IL-25 plays a potent immunosuppressive role in the pathogenesis of RA and CIA by downregulating Th17 cell response, and thus, may be a potential therapeutic agent for RA.

N,N-Dimethylacetamide Significantly Attenuates LPS- and TNFα-Induced Proinflammatory Responses Via Inhibition of the Nuclear Factor Kappa B Pathway

Previously, we have shown that N,N-dimethylacetamide (DMA) prevents inflammation-induced preterm birth in a murine model, inhibits LPS-induced increases in placental pro-inflammatory cytokines and up-regulates the anti-inflammatory cytokine Interleukin-10 (IL-10). However, DMA's mechanism of action remains to be elucidated. In the current study we investigate how DMA produces its anti-inflammatory effect. Using in vitro and ex vivo models, we show that DMA suppresses secretion of pro-inflammatory cytokines in lipopolysaccharide (LPS)-induced RAW 264.7 cells, TNFα-challenged JEG-3 cells and LPS-stimulated human placental explants. DMA significantly attenuated the secretion of TNFα, IL-6, IL-10, and granulocyte macrophage colony stimulating factor (GM-CSF) from LPS-stimulated RAW 264.7 cells, IL-6 secretion from TNFα-stimulated JEG-3 cells and TNFα, IL-6, IL-10, GM-CSF and Interleukin-8 (IL-8) from LPS-stimulated human placental explants. We further investigated if DMA's effect on cytokine expression involves the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. DMA (10 mM) significantly inhibited nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) degradation in LPS-stimulated RAW 264.7 cells, but there was no significant change in the expression of phosphorylated or native forms of downstream proteins in the MAPK pathway. In addition, DMA significantly attenuated luciferase activity in cells co-transfected with NF-κB-Luc reporter plasmid, but not with AP-1-Luc or CEBP-Luc reporters. Overall, our findings suggest that the anti-inflammatory activity of DMA is mediated by inhibition of the NF-κB pathway via decreased IκBα degradation.

Rab27a regulates GM-CSF-dependent priming of neutrophil exocytosis

Neutrophil secretory proteins are mediators of systemic inflammation in infection, trauma, and cancer. In response to specific inflammatory mediators, neutrophil granules are mobilized and cargo proteins released to modulate the microenvironment of inflammatory sites and tumors. In particular, GM-CSF, a cytokine secreted by several immune, nonimmune, and tumor cells, regulates neutrophil priming and exocytosis. Whereas a comprehensive understanding of this process is necessary to design appropriate anti-inflammatory therapies, the molecular effectors regulating GM-CSF-dependent priming of neutrophil exocytosis are currently unknown. With the use of neutrophils deficient in the small GTPase Rab27a or its effector Munc13-4, we show that although both of these secretory factors control matrix metalloproteinase-9 (MMP-9) and myeloperoxidase (MPO) exocytosis in response to GM-CSF, their involvement in exocytosis after GM-CSF priming is very different. Whereas GM-CSF priming-induced exocytosis is abolished in the absence of Rab27a for all secondary stimuli tested, including TLR7, TLR9, and formyl peptide receptor 1 (Fpr1) ligands, cells lacking Munc13-4 showed a significant exocytic response to GM-CSF priming. The mobilization of CD11b was independent of both Rab27a and Munc13-4 in GM-CSF-primed cells unless the cells were stimulated with nucleic acid-sensing TLR ligand, thus highlighting a role for both Rab27a and Munc13-4 in endocytic TLR maturation. Finally, the observation that the absence of Rab27a expression impairs the exocytosis of MMP-9 and MPO under both primed and unprimed conditions suggests that Rab27a is a possible target for intervention in inflammatory processes in which GM-CSF-dependent neutrophil priming is involved.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is released by female mouse bladder urothelial cells and expressed by the urothelium as an early response to lipopolysaccharides (LPS)

AIMS

We studied in vitro and in vivo response of primary mouse bladder urothelial cells (mBUC) and bladder urothelium to lipopolysaccharides (LPS), focusing on granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling.

METHODS

Female C57BL/6 mBUC were exposed for 12 hr to differing concentrations of LPS (100 ng/ml to 10 µg/ml). mBUC were also exposed to a single dose of LPS (1 µg/ml) for 3, 6, 12 hr. Neutralizing GM-CSF antibody (0.1 μg/ml) was used block GM-CSF activity in vitro. In vivo experiments were performed, whereby, LPS (1 mg/ml) was instilled intravesically and left to dwell for 30 min followed by harvest of bladder urothelium 3 to 18 hr later. ELISA measured GM-CSF. qPCR quantitated mRNA for GM-CSF, vascular endothelial growth factor-A (VEGF-A), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and tumor necrosis factor α (TNF-α). RT-PCR was used to detect mRNA for GM-CSF, GM-CSFRα, and β in bladder tissues. Immunohistofluorescence and Western blots for GM-CSFRα were performed on bladder tissues.

RESULTS

LPS induced a dose-dependent release of GM-CSF by mBUC. Mouse bladder urothelium did not express GM-CSF mRNA at baseline, but expressed GM-CSF mRNA 3 hr after in vivo LPS exposure, with GM-CSF mRNA expression disappearing 18 hr later. GM-CSFRα expression was confirmed in bladder urothelium. GM-CSF neutralizing antibody significantly diminished LPS-induced increases of VEGF and COX-2 mRNA expression.

CONCLUSIONS

Urothelium and mBUC secreted GM-CSF as an early response to LPS. GM-CSF mediated downstream expression of VEGF and COX-2. Urothelial GM-CSF may function as a signaling mediator for both inflammation and pain transduction. Neurourol. Urodynam. 36:1020-1025, 2017. © 2016 Wiley Periodicals, Inc.

Guanabenz Downregulates Inflammatory Responses via eIF2α Dependent and Independent Signaling

Integrated stress responses (ISR) may lead to cell death and tissue degeneration via eukaryotic translation initiation factor 2 α (eIF2α)-mediated signaling. Alleviating ISR by modulating eIF2α phosphorylation can reduce the symptoms associated with various diseases. Guanabenz is known to elevate the phosphorylation level of eIF2α and reduce pro-inflammatory responses. However, the mechanism of its action is not well understood. In this study, we investigated the signaling pathway through which guanabenz induces anti-inflammatory effects in immune cells, in particular macrophages. Genome-wide mRNA profiling followed by principal component analysis predicted that colony stimulating factor 2 (Csf2, or GM-CSF as granulocyte macrophage colony stimulating factor) is involved in the responses to guanabenz. A partial silencing of Csf2 or eIF2α by RNA interference revealed that Interleukin-6 (IL6), Csf2, and Cyclooxygenase-2 (Cox2) are downregulated by guanabenz-driven phosphorylation of eIF2α. Although expression of IL1β and Tumor Necrosis Factor-α (TNFα) was suppressed by guanabenz, their downregulation was not directly mediated by eIF2α signaling. Collectively, the result herein indicates that anti-inflammatory effects by guanabenz are mediated by not only eIF2α-dependent but also eIF2α-independent signaling.

Highly sensitive ligand-binding assays in pre-clinical and clinical applications: immuno-PCR and other emerging techniques

Recombinant DNA technology and corresponding innovations in molecular biology, chemistry and medicine have led to novel therapeutic biomacromolecules as lead candidates in the pharmaceutical drug development pipelines. While monoclonal antibodies and other proteins provide therapeutic potential beyond the possibilities of small molecule drugs, the concomitant demand for supportive bioanalytical sample testing creates multiple novel challenges. For example, intact macromolecules can usually not be quantified by mass-spectrometry without enzymatic digestion and isotopically labeled internal standards are costly and/or difficult to prepare. Classical ELISA-type immunoassays, on the other hand, often lack the sensitivity required to obtain pharmacokinetics of low dosed drugs or pharmacodynamics of suitable biomarkers. Here we summarize emerging state-of-the-art ligand-binding assay technologies for pharmaceutical sample testing, which reveal enhanced analytical sensitivity over classical ELISA formats. We focus on immuno-PCR, which combines antibody specificity with the extremely sensitive detection of a tethered DNA marker by quantitative PCR, and alternative nucleic acid-based technologies as well as methods based on electrochemiluminescence or single-molecule counting. Using case studies, we discuss advantages and drawbacks of these methods for preclinical and clinical sample testing.

Disordered haematopoiesis and athero-thrombosis

Atherosclerosis, the major underlying cause of cardiovascular disease, is characterized by a lipid-driven infiltration of inflammatory cells in large and medium arteries. Increased production and activation of monocytes, neutrophils, and platelets, driven by hypercholesterolaemia and defective high-density lipoproteins-mediated cholesterol efflux, tissue necrosis and cytokine production after myocardial infarction, or metabolic abnormalities associated with diabetes, contribute to atherogenesis and athero-thrombosis. This suggests that in addition to traditional approaches of low-density lipoproteins lowering and anti-platelet drugs, therapies directed at abnormal haematopoiesis, including anti-inflammatory agents, drugs that suppress myelopoiesis, and excessive platelet production, rHDL infusions and anti-obesity and anti-diabetic agents, may help to prevent athero-thrombosis.

The physiology of fetal membrane weakening and rupture: Insights gained from the determination of physical properties revisited

Rupture of the fetal membranes (FM) is precipitated by stretch forces acting upon biochemically mediated, pre-weakened tissue. Term FM develop a para-cervical weak zone, characterized by collagen remodeling and apoptosis, within which FM rupture is thought to initiate. Preterm FM also have a weak region but are stronger overall than term FM. Inflammation/infection and decidual bleeding/abruption are strongly associated with preterm premature FM rupture (pPROM), but the specific mechanisms causing FM weakening-rupture in pPROM are unknown. There are no animal models for study of FM weakening and rupture. Over a decade ago we developed equipment and methodology to test human FM strength and incorporated it into a FM explant system to create an in-vitro human FM weakening model system. Within this model TNF (modeling inflammation) and Thrombin (modeling bleeding) both weaken human FM with concomitant up regulation of MMP9 and cellular apoptosis, mimicking the characteristics of the spontaneous FM rupture site. The model has been enhanced so that test agents can be applied directionally to the choriodecidual side of the FM explant consistent with the in-vivo situation. With this enhanced system we have demonstrated that the pathways involving inflammation/TNF and bleeding/Thrombin induced FM weakening overlap. Furthermore GM-CSF production was demonstrated to be a critical common intermediate step in both the TNF and the Thrombin induced FM weakening pathways. This model system has also been used to test potential inhibitors of FM weakening and therefore pPROM. The dietary supplement α-lipoic acid and progestogens (P4, MPA and 17α-hydroxyprogesterone) have been shown to inhibit both TNF and Thrombin induced FM weakening. The progestogens act at multiple points by inhibiting both GM-CSF production and GM-CSF action. The use of a combined biomechanical/biochemical in-vitro human FM weakening model system has allowed the pathways of fetal membrane weakening to be delineated, and agents that may be of clinical use in inhibiting these pathways to be tested.

CD4+ Group 1 Innate Lymphoid Cells (ILC) Form a Functionally Distinct ILC Subset That Is Increased in Systemic Sclerosis

Innate lymphoid cells (ILC) are a heterogeneous group of cellular subsets that produce large amounts of T cell-associated cytokines in response to innate stimulation in the absence of Ag. In this study, we define distinct patterns of surface marker and cytokine expression among the ILC subsets that may further delineate their migration and function. Most notably, we found that the subset previously defined as group 1 ILC (ILC1) contains CD4(+) CD8(-), CD4(-) CD8(+), and CD4(-) CD8(-) populations. Although all ILC1 subsets shared characteristics with Th1 cells, CD4(+) ILC1 also demonstrated significant phenotypic and functional heterogeneity. We also show that the frequencies of CD4(+) ILC1 and NKp44(+) group 3 ILC, but not CD4(-) ILC1 or group 2 ILC, are increased in the peripheral blood of individuals with systemic sclerosis (SSc), a disease characterized by fibrotic and vascular pathology, as well as immune dysregulation. Furthermore, we demonstrate that CD4(+) and CD4(-) ILC1 are functionally divergent based on their IL-6Rα expression and that the frequency of IL-6Rα expression on ILC is altered in SSc. The distinct phenotypic and functional features of CD4(+) and CD4(-) ILC1 suggest that they may have differing roles in the pathogenesis of immune-mediated diseases, such as SSc.

TRAF2 regulates TNF and NF-κB signalling to suppress apoptosis and skin inflammation independently of Sphingosine kinase 1

TRAF2 is a component of TNF superfamily signalling complexes and plays an essential role in the regulation and homeostasis of immune cells. TRAF2 deficient mice die around birth, therefore its role in adult tissues is not well-explored. Furthermore, the role of the TRAF2 RING is controversial. It has been claimed that the atypical TRAF2 RING cannot function as a ubiquitin E3 ligase but counterclaimed that TRAF2 RING requires a co-factor, sphingosine-1-phosphate, that is generated by the enzyme sphingosine kinase 1, to function as an E3 ligase. Keratinocyte-specific deletion of Traf2, but not Sphk1 deficiency, disrupted TNF mediated NF-κB and MAP kinase signalling and caused epidermal hyperplasia and psoriatic skin inflammation. This inflammation was driven by TNF, cell death, non-canonical NF-κB and the adaptive immune system, and might therefore represent a clinically relevant model of psoriasis. TRAF2 therefore has essential tissue specific functions that do not overlap with those of Sphk1.

DOI:http://dx.doi.org/10.7554/eLife.10592.001

Psoriasis is an inflammatory disorder that causes red, flaky patches of skin. The disease affects around 2% of the world’s population, and is most common in people of northern European descent. TNF is one of the key proteins in the development of psoriasis and drugs that inhibit TNF have been very successful in the treatment of this disease. However, these drugs are expensive and for unknown reasons at least 10% of patients do not respond to them.

Attempts to develop better drugs for psoriasis would be assisted by an improved understanding of this disease in terms of the genes and proteins involved. Etemadi et al. set out to obtain a more detailed molecular understanding of this disease by developing new mouse models of the condition. Mice were genetically engineered such that a key gene was deleted specifically from the skin cells that form the main barrier to the environment. These mice demonstrated that defects in skin cells called keratinocytes, rather than defects in the immune response, could lead to a psoriasis-like disease.

Etemadi et al. also showed that the skin cells with this genetic defect die in the presence of TNF and this cell death in mice caused a rapidly-appearing form of psoriasis. However, in the absence of TNF the mice still developed psoriasis, albeit more slowly. In this case, the condition was due to an excessive activation of a protein called NF-κB, which is known to play a role in maintaining balance in the immune system and in psoriasis.

These findings reveal how keratinocytes, cell death and inflammation can directly contribute to psoriasis-like conditions in mice. The next challenge will be to determine whether these findings can be used to help patients with this condition.

DOI:http://dx.doi.org/10.7554/eLife.10592.002