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Frontiers in Immunology 2023() is a Gram-negative obligate intracellular bacterium that causes reproductive tract complications in women, including ectopic pregnancies and tubal factor...
INTRODUCTION
() is a Gram-negative obligate intracellular bacterium that causes reproductive tract complications in women, including ectopic pregnancies and tubal factor infertility. We hypothesized that mast cells, which are common at mucosal barriers, may contribute to responses to infection and aimed to define human mast cell responses to .
METHODS
Human cord blood-derived mast cells (CBMCs) were exposed to to assess bacterial uptake, mast cell degranulation, gene expression, and production of inflammatory mediators. The role of formyl peptide receptors and Toll-like receptor 2 (TLR2) were investigated using pharmacological inhibitors and soluble TLR2. Mast cell-deficient mice and littermate controls were used to examine the role of mast cells in influencing the immune response to infection in the female reproductive tract.
RESULTS
bacteria were taken up by human mast cells but did not replicate efficiently inside CBMCs. -activated mast cells did not degranulate but maintained viability and exhibited cellular activation with homotypic aggregation and upregulation of ICAM-1. However, they significantly enhanced the gene expression of , , , , and . Inflammatory mediators were produced, including TNF, IL-1β, IL-1RA, IL-6, GM-CSF, IL-23, CCL3, CCL5, and CXCL8. Endocytic blockade resulted in reduced gene expression of , , and , suggesting induced mast cell activation in both extracellular and intracellular locations. The IL-6 response to was reduced when CBMCs were treated with coated with soluble TLR2. Mast cells derived from TLR2-deficient mice also demonstrated a reduced IL-6 response to . Five days following infection, mast cell-deficient mice showed attenuated CXCL2 production and significantly reduced numbers of neutrophils, eosinophils, and B cells in the reproductive tract when compared with mast cell-containing littermates.
DISCUSSION
Taken together, these data demonstrate that mast cells are reactive to spp. through multiple mechanisms that include TLR2-dependent pathways. Mast cells also play an important role in shaping immune responses in reproductive tract infection through both effector cell recruitment and modification of the chemokine microenvironment.
Topics: Female; Humans; Animals; Mice; Toll-Like Receptor 2; Interleukin-6; Reproductive Tract Infections; Mast Cells; Inflammation Mediators; Chlamydia trachomatis; Chlamydia Infections
PubMed: 37138882
DOI: 10.3389/fimmu.2023.1166068 -
Cellular and Molecular Gastroenterology... 2023Eosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell...
BACKGROUND AND AIMS
Eosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell carcinoma (ESCC), as their role in ESCC is unknown.
METHODS
Eosinophils were enumerated in tissues from 2 ESCC cohorts. Mice were treated with 4-NQO for 8 weeks to induce precancer or 16 weeks to induce carcinoma. The eosinophil number was modified by a monoclonal antibody to interleukin-5 (IL5mAb), recombinant IL-5 (rIL-5), or genetically with eosinophil-deficient (ΔdblGATA) mice or mice deficient in eosinophil chemoattractant eotaxin-1 (Ccl11). Esophageal tissue and eosinophil-specific RNA sequencing was performed to understand eosinophil function. Three-dimensional coculturing of eosinophils with precancer or cancer cells was done to ascertain direct effects of eosinophils.
RESULTS
Activated eosinophils are present in higher numbers in early-stage vs late-stage ESCC. Mice treated with 4-NQO exhibit more esophageal eosinophils in precancer vs cancer. Correspondingly, epithelial cell Ccl11 expression is higher in mice with precancer. Eosinophil depletion using 3 mouse models (Ccl11 mice, ΔdblGATA mice, IL5mAb treatment) all display exacerbated 4-NQO tumorigenesis. Conversely, treatment with rIL-5 increases esophageal eosinophilia and protects against precancer and carcinoma. Tissue and eosinophil RNA sequencing revealed eosinophils drive oxidative stress in precancer. In vitro coculturing of eosinophils with precancer or cancer cells resulted in increased apoptosis in the presence of a degranulating agent, which is reversed with NAC, a reactive oxygen species scavenger. ΔdblGATA mice exhibited increased CD4 T cell infiltration, IL-17, and enrichment of IL-17 protumorigenic pathways.
CONCLUSION
Eosinophils likely protect against ESCC through reactive oxygen species release during degranulation and suppression of IL-17.
Topics: Animals; Mice; Esophageal Squamous Cell Carcinoma; Eosinophils; Interleukin-17; Esophageal Neoplasms; Reactive Oxygen Species; Carcinoma
PubMed: 37574015
DOI: 10.1016/j.jcmgh.2023.08.005 -
Cell Transplantation 2021Massive cerebral infarction (MCI) is a life-threatening disease and may lead to cerebral herniation. Neutrophil degranulation contributes to ischemic injury in the early...
Massive cerebral infarction (MCI) is a life-threatening disease and may lead to cerebral herniation. Neutrophil degranulation contributes to ischemic injury in the early stage. To investigate whether neutrophil degranulating factors can predict cerebral herniation and the long-term prognosis of patients with MCI and to investigate the relationship between neutrophil degranulation and blood brain barrier (BBB) damage. In this case-control study of 14 MCI patients, we divided the patients into a cerebral hernia group and no cerebral hernia group according to whether they developed cerebral herniation within 5 days. The prognosis of MCI patients was assessed using the Modified Rankin Scale (mRS) score at 6 months, which was the primary end point. The composition of white blood cells (WBC) and degranulating factors for neutrophils in the plasma of MCI patients was determined on days 2 and 4. Baseline characteristics were comparable in both groups. The neurological functional scores and long-term prognosis showed no difference between patients with or without cerebral herniation, while the mortality rate of the cerebral hernia group in the short term was higher ( < 0.05). The WBC count, neutrophil to lymphocyte ratio (NLR) and plasma myeloperoxidase (MPO) levels of patients with cerebral hernia were significantly higher than those of patients without cerebral hernia (all < 0.05). MPO is a better predictor of cerebral herniation, and the NLR showed superior predictive value in the prognosis of MCI patients. neutrophil degranulation may play an important role in malignant cerebral hernia during MCI. These data suggest that, MPO and the NLR might be predictive factors for cerebral herniation and the prognosis of MCI patients.
Topics: Aged; Aged, 80 and over; Case-Control Studies; Cerebral Infarction; Female; Humans; Male; Middle Aged; Neutrophils; Prognosis
PubMed: 33787356
DOI: 10.1177/09636897211004089 -
Arteriosclerosis, Thrombosis, and... Sep 2017On activation, platelets increase glucose uptake, glycolysis, and glucose oxidation and consume stored glycogen. This correlation between glucose metabolism and platelet...
OBJECTIVE
On activation, platelets increase glucose uptake, glycolysis, and glucose oxidation and consume stored glycogen. This correlation between glucose metabolism and platelet function is not well understood and even less is known about the role of glucose metabolism on platelet function in vivo. For glucose to enter a cell, it must be transported through glucose transporters. Here we evaluate the contribution of GLUT3 (glucose transporter 3) to platelet function to better understand glucose metabolism in platelets.
APPROACH AND RESULTS
Platelet-specific knockout of GLUT3 was generated by crossing mice harboring GLUT3 floxed allele to a PF4 (platelet factor 4)-driven Cre recombinase. In platelets, GLUT3 is localized primarily on α-granule membranes and under basal conditions facilitates glucose uptake into α-granules to be used for glycolysis. After activation, platelets degranulate and GLUT3 translocates to the plasma membrane, which is responsible for activation-mediated increased glucose uptake. In vivo, loss of GLUT3 in platelets increased survival in a collagen/epinephrine model of pulmonary embolism, and in a K/BxN model of autoimmune inflammatory disease, platelet-specific GLUT3 knockout mice display decreased disease progression. Mechanistically, loss of GLUT3 decreased platelet degranulation, spreading, and clot retraction. Decreased α-granule degranulation is due in part to an impaired ability of GLUT3 to potentiate exocytosis.
CONCLUSIONS
GLUT3-mediated glucose utilization and glycogenolysis in platelets promotes α-granule release, platelet activation, and postactivation functions.
Topics: Animals; Arthritis, Experimental; Blood Glucose; Blood Platelets; Cell Degranulation; Cytoplasmic Granules; Exocytosis; Genotype; Glucose Transporter Type 3; Glycogenolysis; Glycolysis; Humans; Male; Mice, Inbred C57BL; Mice, Knockout; Phenotype; Platelet Activation; Protein Transport; Pulmonary Embolism; Signal Transduction; Time Factors
PubMed: 28663252
DOI: 10.1161/ATVBAHA.117.309184 -
Frontiers in Immunology 2021Neuromuscular blocking agents (NMBAs) like atracurium and rocuronium as well as fluoroquinolones (FQs) cause mast cell-mediated anaphylaxis by activating Mas-related G...
Neuromuscular blocking agents (NMBAs) like atracurium and rocuronium as well as fluoroquinolones (FQs) cause mast cell-mediated anaphylaxis by activating Mas-related G protein-coupled receptor X2 (MRGPRX2), but many questions remain unanswered. Here, we address three of them, namely whether primary human mast cells show similar activation by these drugs as murine mast cells and mast cell lines, how sugammadex protects from atracurium-induced MRGPRX2-mediated mast cell activation, and why some but not all patients treated with rocuronium develop anaphylaxis. We used peripheral blood-derived cultured mast cells from healthy donors and patients, assessed mast cell activation and degranulation by quantifying intracellular calcium and CD63 expression, respectively, and made use of MRGPRX2-silencing, electroporation with Dicer-substrate small interfering RNAs, and single cell flow cytometric analyses. Atracurium, ciprofloxacin, and levofloxacin activated and degranulated primary human mast cells, but only MRGPRX2-positive and not MRGPRX2-negative or -silenced mast cells. Sugammadex attenuated the atracurium-induced and MRGPRX2-mediated activation and degranulation of human mast cells by reducing free atracurium levels. The mast cells of patients with IgE-independent anaphylaxis to rocuronium were similar, in their MRGPRX2 expression and function, to those of patients with IgE-mediated anaphylaxis. These findings further improve our understanding of the role and relevance of MRGPRX2-driven mast cell activation in anaphylactic reactions to NMBAs and FQs and may help to improve their prediction, prevention, and treatment.
Topics: Anaphylaxis; Anti-Bacterial Agents; Atracurium; Calcium Signaling; Cell Degranulation; Cells, Cultured; Ciprofloxacin; Drug Hypersensitivity; Humans; Immunoglobulin E; Levofloxacin; Mast Cells; Nerve Tissue Proteins; Neuromuscular Nondepolarizing Agents; Receptors, G-Protein-Coupled; Receptors, Neuropeptide; Rocuronium; Time Factors
PubMed: 34385999
DOI: 10.3389/fimmu.2021.668962 -
Journal of Clinical and Experimental... Jul 2023Oral submucous fibrosis (OSMF) is a chronic disorder associated with reduced mouth opening, burning sensation and listed as potentially malignant disorder. The role of... (Review)
Review
Oral submucous fibrosis (OSMF) is a chronic disorder associated with reduced mouth opening, burning sensation and listed as potentially malignant disorder. The role of mast cells in initiation and progression of this condition has been debated in last few years. It is imperative to understand the definitive role of mast cells and subsequently identify a possible cost-efficient treatment modality for OSMF. This review aimed to study the role of mast cells in OSMF by framing a research question that assessed the mast cell count (MCC), their degranulation and immunohistochemical analyses. We performed a comprehensive search of PubMed, EBSCOhost and general Google search that conceded 26 studies from which 15 articles were finalized for the review. The individual study syntheses revealed increased MCC in OSMF as compared to controls. Also, there was decreased MCC with the progression of OSMF. However, the metanalysis showed high level of heterogeneity as three studies out of eight studies found reduced MCC in disease when compared with controls. There is definite increase in mast cell in OSMF although the cell count falls with the advancement of OSMF. This increases the scope for further research to identify exact mechanism by which mast cells contribute to fibrosis and conduct the drug trials that can inhibit the mechanism. Oral submucous fibrosis, mast cell count, degranulated mast cells, stages of OSMF.Oral submucous fibrosis, mast cell count, degranulated mast cells, stages of OSMF.
PubMed: 37519326
DOI: 10.4317/jced.60234 -
Gut Microbes 2012Recently, we demonstrated a novel role for gastrointestinal mast cells (MCs) in the early events that lead to the generation of Th2 immunity to helminth infection. Mice... (Review)
Review
Recently, we demonstrated a novel role for gastrointestinal mast cells (MCs) in the early events that lead to the generation of Th2 immunity to helminth infection. Mice lacking MCs (Kit(W) /Kit(W-v) and Kit(W-Sh)) showed a significant inhibition of Th2 cell priming following infection with the parasitic helminth Heligmosomoides polygyrus bakeri (Hp). We showed that MCs degranulate during the early stages of infection when the helminth larvae invade the small intestinal tissue. Furthermore, MC degranulation was required for the enhanced expression and production of the tissue-derived cytokines IL-25, IL-33 and TSLP, which are required for the optimal orchestration and priming of type 2 immunity. In this addendum we aim to address several questions raised by our findings - in particular, the mechanisms through which MCs may recognize helminth exposure in the early stages of infection and by which they may enhance expression of critical tissue cytokines thus, enabling Th2 priming. Furthermore, we will discuss these findings in the context of recently described novel innate immune cells, such as type 2 hematopoietic progenitors and type 2 innate lymphoid cells.
Topics: Animals; Cell Degranulation; Cytokines; Mast Cells; Mice; Models, Biological; Nematospiroides dubius; Th2 Cells
PubMed: 22892692
DOI: 10.4161/gmic.21507 -
The European Respiratory Journal May 2002It was hypothesized that the distribution and activation of mast cells across the airway wall may reflect their function in asthma. The density of mast cells (intact and...
It was hypothesized that the distribution and activation of mast cells across the airway wall may reflect their function in asthma. The density of mast cells (intact and degranulated) within airway compartments in cartilaginous and membranous airways, obtained from autopsies on patients with fatal asthma, nonfatal asthma, and nonasthmatic control cases have been examined. In cartilaginous airways, the mean+/-SE density of mast cells in control cases was 27+/-9 cells x mm(-2). It was similar in nonfatal asthma (24+/-2 cells x mm(-2)) but reduced (p<0.05) in fatal asthma cases (16+/-2 cells x mm(-2)). In membranous airways, the density of mast cells in control cases was 155+/-21 cells x mm(-2) and was higher (p<0.05) in cases of nonfatal (270+/-51 cells x mm(-2)) and fatal asthma (219+/-26 cells x mm(-2)). Mast-cell density was greatest on the smooth muscle and mucous glands in cartilaginous airways and on the smooth muscle and outer airway wall in membranous airways. The percentage of degranulated mast cells was higher (p<0.05) in cases of asthma, related to disease severity, and was higher in cartilaginous than membranous airways. Degranulation was greatest on the smooth muscle in fatal asthma cases. Mast-cell distribution and degranulation varies between cartilaginous and membranous airways and across the airway wall. Degranulation of mast cells is related to asthma severity. The increased degranulation in proximal airways may reflect stimulation via the inhaled route.
Topics: Adolescent; Adult; Asthma; Cell Degranulation; Female; Humans; Male; Mast Cells; Middle Aged; Respiratory Mucosa
PubMed: 12030728
DOI: 10.1183/09031936.02.00275802 -
Frontiers in Allergy 2022Occupational allergy has been described in employees working in contact with mealworms in pet stores, live fish bait or infested stored grains and recently, in mealworm...
BACKGROUND
Occupational allergy has been described in employees working in contact with mealworms in pet stores, live fish bait or infested stored grains and recently, in mealworm farming for animal feed and human consumption. Mealworm allergens linked to occupational allergy are troponin C, cockroach-like allergen, tropomyosin, arginine kinase, early-staged encapsulation inducing- and larval cuticle proteins.
OBJECTIVE
We report a case of occupational mealworm allergy and studied the culprit component.
METHODS
Diagnosis was done by skin prick, specific IgE, basophil activation and lung function testing. Allergen purification was performed by anion-exchange chromatography and immunoblotting with patient IgE. Allergens were identified by in-gel trypsin digest and tandem mass spectrometry. Allergenicity and specificity further confirmed by IgE inhibition and passive basophil activation experiments.
RESULTS
We describe a new case of occupational mealworm allergy in a laboratory worker, with sensitization to different developmental stages and derivates of the mealworm. In basophil activation tests, the majority of patient's basophils (69%-91%) degranulated upon stimulation with the lowest concentration of mealworm extracts (0.16 µg/ml). Despite strong sensitization to mites, the patient did not show cross-reactivity to other insects. We were able to identify alpha-amylase as the main allergen and through inhibition experiments, we demonstrated that low amounts (0.1 µg/ml) of this allergen could strongly inhibit mealworm specific IgE by 79.1%. Moreover, passive BAT experiments demonstrated the IgE-alpha-amylase interaction to be functional, inducing up to 25.5% degranulation in healthy donor basophils.
CONCLUSION
Alpha-amylase can be identified as the responsible allergen in this specific case of occupational mealworm allergy.
PubMed: 36110144
DOI: 10.3389/falgy.2022.992195 -
Biomedicines Dec 2021Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by increased risk for emphysema, chronic obstructive pulmonary disease (COPD), vasculitis, and wound-healing...
Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by increased risk for emphysema, chronic obstructive pulmonary disease (COPD), vasculitis, and wound-healing impairment. Neutrophils play a central role in the pathogenesis of AATD. Dysregulated complement activation in AATD results in increased plasma levels of C3d. The current study investigated the impact of C3d on circulating neutrophils. Blood was collected from AATD ( = 88) or non-AATD COPD patients ( = 10) and healthy controls (HC) ( = 40). Neutrophils were challenged with C3d, and degranulation was assessed by Western blotting, ELISA, or fluorescence resonance energy transfer (FRET) substrate assays. Ex vivo, C3d levels were increased in plasma ( < 0.0001) and on neutrophil plasma membranes ( = 0.038) in AATD compared to HC. C3d binding to CR3 receptors triggered primary ( = 0.01), secondary ( = 0.004), and tertiary ( = 0.018) granule release and increased CXCL8 secretion ( = 0.02). Ex vivo plasma levels of bactericidal-permeability-increasing-protein ( = 0.02), myeloperoxidase ( < 0.0001), and lactoferrin ( < 0.0001) were significantly increased in AATD patients. In endothelial cell scratch wound assays, C3d significantly decreased cell migration ( < 0.0001), an effect potentiated by neutrophil degranulated proteins ( < 0.0001). In summary, AATD patients had increased C3d in plasma and on neutrophil membranes and, together with neutrophil-released granule enzymes, reduced endothelial cell migration and wound healing, with potential implications for AATD-related vasculitis.
PubMed: 34944741
DOI: 10.3390/biomedicines9121925