Search

Exaggerated airway constriction triggered by repeated exposure to allergen, also called hyperreactivity, is a hallmark of asthma. Whereas vagal sensory neurons are known to function in allergen-induced hyperreactivity1-3, the identity of downstream nodes remains poorly understood. Here we mapped a full allergen circuit from the lung to the brainstem and back to the lung. Repeated exposure of mice to inhaled allergen activated the nuclei of solitary tract (nTS) neurons in a mast cell-, interleukin-4 (IL-4)- and vagal nerve-dependent manner. Single-nucleus RNA sequencing, followed by RNAscope assay at baseline and allergen challenges, showed that a Dbh+ nTS population is preferentially activated. Ablation or chemogenetic inactivation of Dbh+ nTS neurons blunted hyperreactivity whereas chemogenetic activation promoted it. Viral tracing indicated that Dbh+ nTS neurons project to the nucleus ambiguus (NA) and that NA neurons are necessary and sufficient to relay allergen signals to postganglionic neurons that directly drive airway constriction. Delivery of noradrenaline antagonists to the NA blunted hyperreactivity, suggesting noradrenaline as the transmitter between Dbh+ nTS and NA. Together, these findings provide molecular, anatomical and functional definitions of key nodes of a canonical allergen response circuit. This knowledge informs how neural modulation could be used to control allergen-induced airway hyperreactivity.

Our previous work demonstrated that basophils regulate a suite of malaria phenotypes, including intestinal mastocytosis and permeability, the immune response to infection, gametocytemia, and parasite transmission to the malaria mosquito Anopheles stephensi. Given that activated basophils are primary sources of the regulatory cytokines IL-4 and IL-13, we sought to examine the contributions of these mediators to basophil-dependent phenotypes in malaria. We generated mice with basophils depleted for IL-4 and IL-13 (baso IL-4/IL-13 (-)) and genotype controls (baso IL-4/IL-13 (+)) by crossing mcpt8-Cre and Il4/Il13fl/fl mice and infected them with Plasmodium yoelii yoelii 17XNL. Conditional deletion was associated with ileal mastocytosis and mast cell (MC) activation, increased intestinal permeability, and increased bacterial 16S levels in blood, but it had no effect on neutrophil activation, parasitemia, or transmission to A. stephensi. Increased intestinal permeability in baso IL-4/IL-13 (-) mice was correlated with elevated plasma eotaxin (CCL11), a potent eosinophil chemoattractant, and increased ileal MCs, proinflammatory IL-17A, and the chemokines MIP-1α (CCL3) and MIP-1β (CCL4). Blood bacterial 16S copies were positively but weakly correlated with plasma proinflammatory cytokines IFN-γ and IL-12p40, suggesting that baso IL-4/IL-13 (-) mice failed to control bacterial translocation into the blood during malaria infection. These observations suggest that basophil-derived IL-4 and IL-13 do not contribute to basophil-dependent regulation of parasite transmission, but these cytokines do orchestrate protection of intestinal barrier integrity after P. yoelii infection. Specifically, basophil-dependent IL-4/IL-13 control MC activation and prevent infection-induced intestinal barrier damage and bacteremia, perhaps via regulation of eosinophils, macrophages, and Th17-mediated inflammation.

Peyers patches (PPs) are lymphoid structures situated adjacent to the intestinal epithelium that support B cell responses that give rise to many intestinal IgA-secreting cells. Induction of isotype switching to IgA in PPs requires interactions between B cells and TGFβ-activating conventional dendritic cells type 2 (cDC2s) in the subepithelial dome (SED). However, the mechanisms promoting cDC2 positioning in the SED are unclear. Here, we found that PP cDC2s express GPR35, a receptor that promotes cell migration in response to various metabolites, including 5-hydroxyindoleacetic acid (5-HIAA). In mice lacking GPR35, fewer cDC2s were found in the SED, and frequencies of IgA+ germinal center (GC) B cells were reduced. IgA plasma cells were reduced in both the PPs and lamina propria. These phenotypes were also observed in chimeric mice that lacked GPR35 selectively in cDCs. GPR35 deficiency led to reduced coating of commensal bacteria with IgA and reduced IgA responses to cholera toxin. Mast cells were present in the SED, and mast cell-deficient mice had reduced PP cDC2s and IgA+ cells. Ablation of tryptophan hydroxylase 1 (Tph1) in mast cells to prevent their production of 5-HIAA similarly led to reduced PP cDC2s and IgA responses. Thus, mast cell-guided positioning of GPR35+ cDC2s in the PP SED supports induction of intestinal IgA responses.

This study assessed the effects of red and green LEDs on mast cells (MCs) in third‐degree burns in 75 Wistar rats, divided into control, red LED (RED), and green LED (GREEN) groups. Animals were irradiated daily with RED (630 nm, 300 mW, 0.779 W/cm2, 9 J/cm2, 30 s) and GREEN (520 nm, 180 mW, 0.467 W/cm2, 60 J/cm2, 30 s). Histological sections stained with toluidine blue were analyzed for total and subtype MCs. Standardized MC counting was performed across the viable lesion area, considering lesion margins, through intact connective tissue and the integrity of skin appendages. No statistically significant differences in MCs 2 (with released granules and intact cell border) were found between groups. Irradiated groups showed increased total MCs at 7, 14, and 21 days (p < 0.05), with a decrease in MCs 1 (intact MCs) at all time points compared to control (p < 0.05). Significant changes in MCs 3 (with massive degranulation and partial or complete disintegration of the cell border) degranulation were noted in RED at 7, 14, and 21 days (p < 0.009) and in GREEN at 14 (p < 0.009) and 32 days (p < 0.028). Results suggest red and green LEDs modulate MC recruitment and degranulation in third‐degree burns. [ABSTRACT FROM AUTHOR]

Background: Equine asthma is a common, non-infectious, chronic lung disease that affects up to 80% of the horse population. Strict phenotyping and identification of subclinically asthmatic horses can be challenging. The aim of this study was to describe equine asthma phenotypes (mild, moderate, and severe asthma) defined by BALF cytology and occurrence of clinical signs in a population of privately owned horses and to identify the variables and examination steps with best discriminative potential. The standardised examination protocol included clinical examinations, blood work, airway endoscopy with bronchoalveolar lavage fluid analysis, arterial blood gas analysis and radiography under clinical conditions performed by one veterinarian. Results: Out of 26 horses, four were diagnosed with mild (subclinical), seven with moderate, and seven with severe asthma based on clinical examination and BALF cytology. Eight horses served as controls. Cough with history of coughing was the strongest variable in phenotype differentiation. Factor analysis revealed an increasing clinical variability with disease severity and an overlapping of clinical presentations between phenotypes. Elevated mast cell (4/4 horses) and neutrophil counts (3/4 horses) in bronchoalveolar lavage cytology differentiated mild asthmatic horses from healthy horses. Moderate and severe asthmatic horses were characterised by clinical signs and neutrophil counts. Conclusions: The results indicate that medical history, clinical examination and bronchoalveolar lavage cytology are minimum indispensable steps to diagnose equine asthma and that phenotypes are clinically overlapping. A differentiation of three phenotypes without neutrophil and mast cell counts in bronchoalveolar lavage cytology is not sufficient for clinical diagnostics. A comparably exact diagnosis cannot be achieved by relying on alternative examinations used in this study. Screenings of inconspicuous horses with bronchoalveolar lavage can aid in diagnosing subclinically affected animals, however, group size was small, the procedure is invasive and clinical relevance of slightly elevated cells in bronchoalveolar lavage remains unclear. Clinical relevance could not be clarified in this study, since follow-up examinations or lung function testing were not performed. [ABSTRACT FROM AUTHOR]

Steroid-induced osteonecrosis of the femoral head (SONFH) is a debilitating condition caused by long-term corticosteroid use, leading to impaired blood flow and bone cell death. The disruption of cellular processes and promotion of apoptosis by endoplasmic reticulum stress (ERS) is implicated in the pathogenesis of SONFH. We identified ERS-associated genes in SONFH and investigated their potential as therapeutic targets. We analysed the GSE123568 GEO dataset to identify differentially expressed genes (DEGs) related to ERS in SONFH. We conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, identified hub genes by protein-protein interaction (PPI) analyses, and evaluated their functions by gene set enrichment analysis (GSEA). We constructed mRNA–miRNA networks, identified potential therapeutics, and assessed immune cell infiltration. We performed cross-validation using the GEO dataset GSE74089, qRT-PCR on clinical samples from patients with SONFH and controls, and a receiver operating characteristic (ROC) curve analysis to assess the diagnostic performance of the hub genes. We identified 195 ERS-related genes in SONFH, which were primarily involved in oxidative stress, immune responses, and metabolic pathways. The PPI network suggested CXCL8, STAT3, IL1B, TLR4, PTGS2, TLR2, CASP1, CYBB, CAT, and HOMX1 to be key hub genes, which were shown by GSEA to be involved in biological pathways related to metabolism, immune modulation, and cellular integrity. We also identified 261 microRNAs (miRNAs) as well as drugs such as dibenziodolium and N-acetyl-L-cysteine that modulated inflammatory responses in SONFH. Twenty-two immune cell subtypes showed significant correlations, such as a positive correlation between activated mast cells and Tregs, and patients with SONFH had fewer dendritic cells than controls. The hub genes CYBB and TLR4 showed significant correlations with M1 macrophages and CD8 T cells, respectively. Cross-validation and qRT-PCR confirmed the upregulation of STAT3, IL1B, TLR2, and CASP1 in patients with SONFH, validating the bioinformatics findings. An ROC curve analysis confirmed the diagnostic potential of the hub genes. The top 10 hub genes show promise as ERS-related diagnostic biomarkers for SONFH. We discovered that 261 miRNAs, including hsa-miR-23, influence these genes and identified potential therapeutics such as dibenziodolium and simvastatin. Immune profiling indicated altered immune functions in SONFH, with significant correlations among immune cell types. Validation confirmed the upregulation of STAT3, IL1B, TLR2 and CASP1, which had diagnostic potential. The findings suggest potential diagnostic markers and therapeutic targets for SONFH. [ABSTRACT FROM AUTHOR]

Long‐COVID caused by SARS‐CoV‐2 infection has significant and increasing effects on human health worldwide. Although a unifying molecular or biological explanation is lacking, several pathophysiological mechanisms have been proposed. Involvement of mast cells—evolutionary old “multipurpose” innate immune cells—was reported recently in studies of acute infection and post‐acute‐COVID‐19 syndrome. Mast cell activity has been suggested in long‐COVID. In this case–control study, we compared data from 24 individuals with long‐COVID (according to the NICE criteria) and 24 age‐ and sex‐matched healthy individuals with a history of SARS‐CoV‐2 infection without developing sequelae. Serum levels of the proteases beta‐tryptase (TPSB2) and carboxypeptidase (CPA3), which are mast cell specific, were measured using immunoassays. The values were compared between the two groups and correlated to measures of physical exertional intolerance. TPSB2 and CPA3 levels were median (range) 26.9 (2.0–1000) and 5.8 (1.5–14.0) ng/mL, respectively, in the long‐COVID group. The corresponding values in the control group were 10.9 (2.0–1000) (p = 0.93) and 5.3 (3.5–12.9) ng/mL (p = 0.82). No significant correlations between TPSB2 or CPA3 levels and scores on the ten physical subscales of SF‐36, 3.1–3.10 were revealed. We found no significant differences in the levels of mast cell activation markers TPSB2 and CPA3 between the long‐COVID and control groups and no correlations with proxy markers of exercise intolerance. Mast cell activation does not appear to be part of long‐term pathogenesis of long‐COVID, at least in the majority of patients. [ABSTRACT FROM AUTHOR]

Background: Glioma is the most common brain tumor. IDH mutations occur frequently in glioma, indicating a more favorable prognosis. We aimed to explore energy metabolism-related genes in glioma to promote the research and treatment. Methods: Datasets were obtained from TCGA and GEO databases. Candidate genes were screened by differential gene expression analysis, then functional enrichment analysis was conducted on the candidate genes. PPI was also carried out to help determine the target gene. GSEA and DO analysis were conducted in the different expression level groups of the target gene. Survival analysis and immune cell infiltrating analysis were performed as well. Results: We screened 34 candidate genes and selected GLUD1 as the target gene. All candidate genes were significantly enriched in 10 KEGG pathways and 330 GO terms. GLUD1 expression was higher in IDH-mutant samples than IDH-wildtype samples, and higher in normal samples than tumor samples. Low GLUD1 expression was related to poor prognosis according to survival analysis. Most types of immune cells were negatively related to GLUD1 expression, but monocytes and activated mast cells exhibited significantly positive correlation with GLUD1 expression. GLUD1 expression was significantly related to 119 drugs and 6 immune checkpoint genes. GLUD1 was able to serve as an independent prognostic indicator of IDH-mutant glioma. Conclusion: In this study, we identified an energy metabolism-related gene GLUD1 potentially contributing to favorable clinical outcomes of IDH-mutant glioma. In glioma, GLUD1 related clinical outcomes and immune landscape were clearer, and more valuable information was provided for immunotherapy. [ABSTRACT FROM AUTHOR]

Neuromuscular blocking agents (NMBAs) relax skeletal muscles to facilitate surgeries and ease intubation but can lead to adverse reactions, including complications because of postoperative residual neuromuscular blockade (rNMB) and, in rare cases, anaphylaxis. Both adverse reactions vary between types of NMBAs, with rocuronium, a widely used nondepolarizing NMBA, inducing one of the longest rNMB durations and highest anaphylaxis incidences. rNMB induced by rocuronium can be reversed by the synthetic γ-cyclodextrin sugammadex. However, in rare cases, sugammadex can provoke anaphylaxis. Thus, additional therapeutic options are needed. Rocuronium-induced anaphylaxis is proposed to rely on preexisting rocuronium-binding antibodies. To understand the pathogenesis of rocuronium-induced anaphylaxis and to identify potential therapeutics, we investigated the memory B cell antibody repertoire of patients with suspected hypersensitivity to rocuronium. We identified polyclonal antibody repertoires with a high diversity among V(D)J genes without evidence of clonal groups. When recombinantly expressed, these antibodies demonstrated specificity and low affinity for rocuronium without cross-reactivity for other NMBAs. Moreover, when these antibodies were expressed as human immunoglobulin E (IgE), they triggered human mast cell activation and passive systemic anaphylaxis in transgenic mice, although their affinities were insufficient to serve as reversal agents. Rocuronium-specific, high-affinity antibodies were thus isolated from rocuronium-immunized mice. The highest-affinity antibody was able to reverse rocuronium-induced neuromuscular blockade in nonhuman primates with kinetics comparable to that of sugammadex. Together, these data support the hypothesis that antibodies cause anaphylactic reactions to rocuronium and pave the way for improved diagnostics and neuromuscular blockade reversal agents. Editor's summary: Neuromuscular blocking agents (NMBAs) such as rocuronium are used during anesthesia to assist with surgeries and intubations. Although these agents are effective, they are not without risk. Patients can develop postoperative residual neuromuscular blockade, which can be treated with an NMBA reversal agent, and life-threatening anaphylaxis can occur in rare cases. Here, Dejoux et al. isolated and characterized memory B cells from three individuals who developed reactions to NMBA treatment and had serum antibodies to rocuronium. The authors found that IgE antibodies generated from these memory B cells were sufficient to induce anaphylaxis in mice treated with rocuronium, although they were too low affinity to be used as reversal agents. This led the authors to immunize mice with rocuronium to generate antibodies of higher affinity, which were able to reverse neuromuscular blockade in rocuronium-treated nonhuman primates. Together, these data explain why these three patients had a reaction and offer a therapeutic approach to reversing neuromuscular blockade. —Courtney Malo [ABSTRACT FROM AUTHOR]

Objective: Schizonepeta tenuifolia -Saposhnikovia divaricata (Jingjie-Fangfeng, JF) has been used for years to treat allergic inflammatory skin diseases like atopic dermatitis, but the specific effects and mechanisms of JF are still unclear. Purpose: We aim to investigate the therapeutic effect and mechanism of JF in MC903-induced atopic dermatitis-like model. Methods: JF decoction was subjected to rigorous HPLC and GC analysis. The JF decoction was then freshly prepared and administered to MC903-induced atopic dermatitis -like mice models to investigate its therapeutic effects. Our evaluation focused on several markers of inflammation including the TEWL index, ear thickness, swelling, and specific inflammation indicators such as TSLP, IL33, IgE, and immune cell presence at the lesion sites. We measured Transient Receptor Potential Vanilloid 1 (TRPV1) expression levels through immunofluorescent staining in skin tissue from both atopic dermatitis patients and the MC903-treated mice. Furthermore, TRPV1 expression and macrophage activation markers were measured in LPS/IFN-γ-stimulated Raw264.7 and THP-1 cell models in vitro. Additionally, we developed cell lines that overexpress TRPV1 and investigated how JF treatment affects NF-κB p65 phosphorylation in these cells to understand better the role of TRPV1 in atopic dermatitis. Results: The JF decoction met the standards outlined in the Chinese pharmacopeia. The JF decoction significantly alleviated inflammatory skin symptoms and helped restore skin barrier function. Additionally, it reduced the levels of IgE and pro-inflammatory cytokines TSLP, IL-33, and IL-4. There was also a noticeable decrease in mast cell infiltration and degranulation. Notably, JF decoction reduced infiltrated macrophages with limited affection on T cell infiltration. It also decreased F4/80+/TRPV1+ cells in atopic dermatitis mice and TRPV1 expression in LPS/IFNγ-stimulated microphages. Additionally, we observed that CD68+/TRPV1+ cells increased in human atopic dermatitis tissue. Further studies showed that JF water extract (JF-WE) suppressed TRPV1 expression in macrophages, potentially by affecting NF-κB p65 phosphorylation rather than the JAK-STAT6 pathway. Conclusion: This study offers initial evidence of the effectiveness of JF-WE in suppressing inflammation in atopic dermatitis. The therapeutic effect might stems from its ability to downregulate TRPV1 expression and subsequent NF-κB p65 phosphorylation in macrophages. [ABSTRACT FROM AUTHOR]

IntroductionMethodsResultsDiscussionAnaphylaxis is a globally increasing allergic reaction that is often fatal. Recently, our previous study reported the possibility of using the modified natural products “sodium R-lipoate (NaRLA) and enzymatically modified isoquercitrin (EMIQ)“ as potential novel safe agents against the non-immunological-degranulation of mast cells.Here, we extended our previous findings by determining the antianaphylactic activity of 50 and 100 mg/kg body weight of NaRLA and EMIQ (given orally and prior to local or systemic challenge) in mice models of ovalbumin (OVA)-induced IgE-dependent active cutaneous anaphylaxis (ACA) and active systemic anaphylaxis (ASA) in comparison with sulfasalazine (SSZ, amast cell stabilizer).The pre-treatment of mice with NaRLA or EMIQ completely succeeded, as SSZ, in suppression of the increased vascular permeability associated with IgE-dependent ACA and protected the OVA-sensitized mice from fatal ASA by reducing (p < .001) the skin mast cell degranulation, the elevated peritoneal histamine and interleukin-4 levels, along with decreasing the associated sever gastrointestinal and lung histopathological alterations and inflammation. The high dose of EMIQ prevented death in 70% of mice with anaphylactic shock, better than SSZ.Our data indicated that NaRLA and EMIQ may be potential prophylactic and therapeutic candidates for the alleviation of atopic and systemic anaphylaxis. [ABSTRACT FROM AUTHOR]

IntroductionMethodsResultsDiscussionNovel treatments are being researched to develop more safe and effective protective medications for anaphylaxis. Camel whey protein (CWP) and baicalein (BAC, one of the major flavones) have multiple beneficial properties including anti-inflammatory and antioxidant activities.The current study investigated/compared the therapeutic protection of repeated intragastric administration of CWP (100 mg/kg body weight, as an animal extract) and BAC (10 mg/kg body weight, as a plant extract), before the challenge with ovalbumin (OVA) or receiving the compound 48/80 (C48/80), against mice models for IgE-independent and dependent anaphylaxes. Besides, their effects on mast cells (MCs) downstream cell signaling were explored.The results revealed that CWP and BAC reduced the mortality rate, as compared with a MCs stabilizer “sulfasalazine (SSZ, 100 mg/kg body weight, intraperitoneally),” in both mice models. Furthermore, they prevented the MCs degranulation and significantly reduced (p < .05) lung tissue levels of cell signaling (p-AKT, p-ERK, and p-IκBα). Additionally, they decreased histamine, tryptase, leukotriene C4, prostaglandin D2, interleukin (IL)-4, and IL-10 levels in broncho-alveolar and peritoneal lavages in systemic anaphylaxis mice models. They also restored the stabilization of peritoneal MCs membrane in inverted light microscopy results accompanied by amelioration of the lung histology.The present study provided evidence for the protective therapeutic effect of CWP and BAC against anaphylaxis. As a result, CWP and BAC may be used as preventative supplemented regimens for both non-vegetarian and vegetarian consumers to treat allergy through downregulation of MCs signal transduction pathways, and hence controlling the production of inflammatory mediators. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Tryptase, a mast cell protease, has been identified as a potential therapeutic target in managing patients with refractory asthma. We assessed the efficacy, safety, pharmacokinetics, and pharmacodynamics of MTPS9579A, an anti‐tryptase antibody, in a phase 2a randomized trial for patients with uncontrolled asthma and a phase 1c trial to understand activity within the lower respiratory tract.Phase 2a patients (n = 134) received 1800 mg MTPS9579A or placebo intravenously every 4 weeks for 48 weeks. The primary endpoint was time to the first composite exacerbation event. Phase 1c patients (n = 27) received one intravenous dose of 300 or 1800 mg MTPS9579A or placebo. Both trials measured MTPS9579A concentrations and effects on tryptase in serum and nasal lining fluid; phase 1c also analyzed bronchial lining fluid.MTPS9579A did not meet the primary endpoint (hazard ratio = 0.90; 95% CI: 0.55–1.47; p = 0.6835); exacerbation rates in the placebo group were low. Serum and nasal MTPS9579A pharmacokinetics and tryptase levels were consistent with data from healthy volunteers. However, in phase 1c patients, compared to nasal levels, MTPS9579A bronchial concentrations were 6.8‐fold lower, and bronchial active and total tryptase levels were higher (119‐fold and 30‐fold, respectively). Pharmacokinetic/pharmacodynamic modeling predicted intravenous doses of 3800 mg every 4 weeks would be necessary to achieve 95% active tryptase inhibition from baseline.The MTPS9579A dose tested in the phase 2a study was insufficient to inhibit tryptase in bronchial lining fluid, likely contributing to the observed lack of efficacy. [ABSTRACT FROM AUTHOR]

Mast cells serve as crucial effector cells within the innate immune system and are predominantly localized in the skin, airways, gastrointestinal tract, urinary and reproductive tracts, as well as in the brain. Under physiological conditions, brainresident mast cells secrete a diverse array of neuro-regulatory mediators to actively participate in neuroprotection. Meanwhile, as the primary source of molecules causing brain inflammation, mast cells also function as the "first responders" in brain injury. They interact with neuroglial cells and neurons to facilitate the release of numerous inflammatory mediators, proteases, and reactive oxygen species. This process initiates and amplifies immuneinflammatory responses in the brain, thereby contributing to the regulation of neuroinflammation and blood-brain barrier permeability. This article provides a comprehensive overview of the potential mechanisms through which mast cells in the brain may modulate neuroprotection and their pathological implications in various neurological disorders. It is our contention that the inhibition of mast cell activation in brain disorders could represent a novel avenue for therapeutic breakthroughs. [ABSTRACT FROM AUTHOR]

The etiology of interstitial cystitis/bladder pain syndrome (IC/BPS) is unknown but likely multifactorial. IC/BPS symptoms can be exacerbated by psychological stress, but underlying mechanisms remain to be defined. Transient receptor potential vanilloid 1 (TRPV1) channels, expressed on nerve fibers, have been implicated in bladder dysfunction and colonic hypersensitivity with stress in rodents. Histamine/H1R activation of TRPV1+ nerves increases bladder afferent fiber sensitivity to distension. TRPV1 channels are also expressed on mast cells, previously implicated in contributing to IC/BPS etiology and symptoms. We have examined the contribution of TRPV1 and mast cells to bladder dysfunction after repeated variate stress (RVS). RVS increased (P ≤ 0.05) serum and fecal corticosterone expression and induced anxiety-like behavior in wild-type (WT) mice. Intravesical instillation of the selective TRPV1 antagonist capsazepine (CPZ) rescued RVS-induced bladder dysfunction in WT mice. Trpv1 knockout (KO) mice did not increase voiding frequency with RVS and did not exhibit increased serum corticosterone expression despite exhibiting anxiety-like behavior. Mast cell-deficient mice (B6.Cg-Kitw-sh) failed to demonstrate RVS-induced increased voiding frequency or serum corticosterone expression, whereas control (no stress) mast cell-deficient mice had similar functional bladder capacity to WT mice. TRPV1 protein expression was significantly increased in the rostral lumbar (L1-L2) spinal cord and dorsal root ganglia (DRG) in WT mice exposed to RVS, but no changes were observed in lumbosacral (L6-S1) spinal segments or DRG. These studies demonstrated TRPV1 and mast cell involvement in RVS-induced increased voiding frequency and suggest that TRPV1 and mast cells may be useful targets to mitigate stress-induced urinary bladder dysfunction. NEW & NOTEWORTHY: Using pharmacological tools and transgenic mice in a repeated variate stress (RVS) model in female mice, we demonstrate that transient receptor potential vanilloid 1 (TRPV1) and mast cells contribute to the increased voiding frequency observed following RVS. TRPV1 and mast cells should continue to be considered as targets to improve bladder function in stress-induced bladder dysfunction. [ABSTRACT FROM AUTHOR]

A 12‐year‐old male domestic cat with multiple subcutaneous mast cell tumours (MCTs) presented with a 2‐week history of pruritus and raw/bleeding skin from self‐trauma at Kagoshima University Veterinary Teaching Hospital. Polymerase chain reaction (PCR) and histopathological analyses revealed intertumoral heterogeneity among tumour locations based on the mutation status of KIT. In addition, the expression pattern of KIT was characterized. After failed treatment with vinblastine (2.0–2.2 mg/m2, intravenous administration, two doses in total) or nimustine (25 mg/m2, intravenous administration, two doses in total), toceranib (2.2–2.6 mg/kg, orally administered, every other day) was administered to treat recurrent MCTs harbouring the KIT exon eight internal tandem duplication mutation, achieving a complete response. However, toceranib resistance developed 2 months after treatment initiation. Subsequent PCR analysis was conducted to identify the mutational status of KIT in each MCT and to detect the presence of secondary mutations associated with the acquisition of toceranib resistance. Secondary KIT mutations (c.998G>C and c.2383G>C), which were not initially detected in tumour cells at diagnosis, were identified after the development of resistance to toceranib. This indicates that the tumour cells in feline MCTs in the same case have diverse characteristics. Our findings encourage further investigation into the development of therapeutic strategies for feline MCTs, particularly focusing on the heterogeneous nature of KIT/KIT and overcoming acquired resistance to toceranib. [ABSTRACT FROM AUTHOR]

Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) is a rare and poorly understood disease characterised by the infiltration of eosinophils and the development of fibrous tissue within the gastrointestinal tract of cats. A 2‐year‐old female neutered Ragdoll was presented for signs consistent with extrahepatic biliary tract obstruction (EHBO), including jaundice, hyporexia and lethargy. Marked progressive hyperbilirubinemia and mild anaemia were also present. Abdominal ultrasonography suggested a duodenal mass and pancreatitis as the cause of EHBO. Cytopathological results from fine needle aspirates detected mast cells and eosinophils in the duodenal mass and eosinophils in the spleen and the liver, suggestive of a possible mast cell tumour. A cholecystojejunostomy and a duodenotomy were performed to divert the biliary outflow and obtain biopsy samples, respectively. Eosinophilic sclerosing fibroplasia in the duodenal mass and fungal elements in an abdominal lymph node were reported on histopathological examination. A pan‐fungal PCR targeting ITS2 performed on DNA extracted from an abdominal lymph node detected Candida albicans. This report adds to the growing body of evidence that FGESF can occur in association with fungal infections. [ABSTRACT FROM AUTHOR]

Immune activation status determines non-small cell lung cancer (NSCLC) prognosis, with reported positive/negative associations for T helper type 2 (TH2) responses, including allergen-specific IgE and eosinophils. Our study seeks to explore the potential impact of these comorbid immune responses on the survival rates of patients with NSCLC. Our retrospective study used data from the Data Warehouse of the German Center for Lung Research (DZL) and Lung Biobank at Thoraxklinik Heidelberg. We estimated the association of blood eosinophilia and neutrophilia on survival rates in an inflammatory cohort of 3143 patients with NSCLC. We also tested sensitization to food and inhalants and high-sensitivity C-reactive protein (hs-CRP) in a comorbidity cohort of 212 patients with NSCLC. Finally, we estimated the infiltration of immune-relevant cells including eosinophils, T-cells, and mast cells in a tissue inflammatory sub-cohort of 60 patients with NSCLC. Sensitization to at least one food or inhalant (sIgE) was higher in patients with adenocarcinoma (adeno-LC) than the non-adenocarcinoma (non-adeno-LC). Furthermore, hs-CRP was higher in non-adeno-LC compared with adeno-LC. Peripheral inflammation, particularly eosinophilia and neutrophilia, was associated with poor survival outcomes in NSCLC with a clear difference between histological subgroups. Finally, blood eosinophilia was paralleled by significant eosinophil infiltration into the peritumoral tissue in the lung. This study provides novel perspectives on the crucial role of peripheral inflammation, featuring eosinophilia and neutrophilia, with overall survival, underscoring distinctions between NSCLC subgroups (adeno-LC vs. non-adeno-LC). Peripheral eosinophilia enhances eosinophil infiltration into tumors. This sheds light on the complex interplay between inflammation, eosinophil infiltration, and NSCLC prognosis among various histological subtypes. Further studies are required to underscore the role of eosinophils in NSCLC among different histological subgroups and their role in shaping the tumor microenvironment. [ABSTRACT FROM AUTHOR]

Chronic spontaneous urticaria (CSU) is associated with skin mast cell activation, and its triggering mechanisms are not completely elucidated. Evidence suggests an autoimmune component of CSU. Our aim was to assess the usefulness of an autoimmune mast cell activation test (aiMAT) for diagnosing and differentiating CSU into different subtypes. We enrolled 43 patients with active, uncontrolled CSU before starting treatment with omalizumab and 15 controls. Patients were evaluated based on omalizumab response. aiMATs were performed using non-IgE-sensitized (NS) or myeloma IgE-sensitized (S) LAD2 cells, which were then stimulated with CSU/control sera (25 µL and 10 µL). The expression of CD63 was assessed with flow cytometry. CD63 response on NS-LAD2 was significantly increased in CSU patients compared to controls after the stimulation with 25 µL CSU/control sera (p = 0.0007) and with 10 µL CSU/control sera (p = 0.0001). The ROC curve analysis demonstrated an area under the curve (AUC) of 0.82. The cutoff for autoimmune-non-IgE-sensitized-MAT was 40.3% CD63+ LAD2, which resulted in 73.3% sensitivity and 81.4% specificity. CD63 response on S-LAD2 was significantly increased in CSU patients compared to controls after the stimulation with 25 µL CSU/control sera (p = 0.03). The ROC curve analysis demonstrated an AUC of 0.66. The cutoff for the autoimmune-myeloma IgE-sensitized-MAT was 58.4% CD63+ cells, which resulted in 62.8% sensitivity and 66.7% specificity. Overall, 36 out of 43 (84%) patients responded to omalizumab, and 7 (16%) were nonresponders. We found no differences between LAD2 CD63 response and response to omalizumab. In conclusion, aiMAT could represent a new diagnostic tool in CSU. Additional studies are needed to evaluate the potential benefits during omalizumab therapy. [ABSTRACT FROM AUTHOR]

Marfan syndrome (MFS) is a hereditary condition accompanied by disorders in the structural and regulatory properties of connective tissue, including elastic fibers, due to a mutation in the gene encodes for fibrillin-1 protein (FBN1 gene) and the synthesis of abnormal fibrillin-1 glycoprotein. Despite the high potential of mast cells (MCs) to remodel the extracellular matrix (ECM), their pathogenetic significance in MFS has not been considered yet. The group of patients with Marfan syndrome included two mothers and five children (three girls aged 4, 11, and 11 and two boys aged 12 and 13). Normal skin was examined in two children aged 11 and 12. Histochemical, monoplex, and multiplex immunohistochemical techniques; combined protocols of simultaneous histochemical and immunohistochemical staining (the results of staining were assessed using light, epifluorescence, and confocal microscopy); and bioinformatics algorithms for the quantitative analysis of detected targets were used to evaluate mast cells and their relationship with other cells from extracellular structures in the skin dermis. Analysis of the skin MC population in children with Marfan syndrome revealed a considerably increased number of intra-organic populations with the preservation of the specific Tryptase+Chymase+CPA3+ protease profile typical of the skin. The features of the MC histotopography phenotype in MFS consisted of closer colocalization with elastic fibers, smooth muscle cells, and fibroblasts. MCs formed many intradermal clusters that synchronized the activity of cell functions in the stromal landscape of the tissue microenvironment with the help of spatial architectonics, including the formation of cell chains and the creation of fibrous niches. In MCs, the expression of specific proteases, TGF-β, and heparin increased, with targeted secretion of biologically active substances relative to the dermal elastic fibers, which had specific structural features in MFS, including abnormal variability in thickness along their entire length, alternating thickened and thinned areas, and uneven surface topography. This paper discusses the potential role of MCs in strain analysis (tensometry) of the tissue microenvironment in MFS. Thus, the quantitative and qualitative rearrangements of the skin MC population in MFS are aimed at altering the stromal landscape of the connective tissue. The results obtained should be taken into account when managing clinical signs of MFS manifested in other pathogenetically critical structures of internal organs, including the aorta, tendons, cartilage, and parenchymal organs. [ABSTRACT FROM AUTHOR]

Arteriogenesis is an inflammatory driven mechanism, describing the growth of a natural bypass from pre-existing collateral arteries to compensate for an occluded artery. The complement system component C3 is a potent natural inflammatory activator. Here, we investigated its impact on the process of collateral artery growth using C3-deficient (C3 −/−) and wildtype control mice in a murine hindlimb model of arteriogenesis. Induction of arteriogenesis by unilateral femoral artery ligation resulted in decreased perfusion recovery in C3 −/− mice on day 7 as shown by Laser Doppler imaging. Immunofluorescence staining revealed a reduced vascular cell proliferation in C3 −/− mice. Gene expression analysis displayed a significant reduction in monocyte chemoattractant protein-1 (MCP-1) expression in C3 −/− mice. Interestingly, 3 days after induction of arteriogenesis, the number of macrophages (CD68+) recruited to growing collaterals was not affected by C3 deficiency. However, a significant reduction in inflammatory M1-like polarized macrophages (CD68+/MRC1−) was noted. Forced mast cell activation by Compound 48/80 as well as exogenous MCP-1 application rescued the number of M1-like polarized macrophages along with perfusion recovery in C3 −/− mice. In summary, this study demonstrates that complement C3 influences arteriogenesis by mediating MCP-1 expression, which is essential for the induction and enhancement of sterile inflammation. [ABSTRACT FROM AUTHOR]

Introduction: In chronic spontaneous urticaria (CSU), interleukin (IL)-4 and IL-13 may promote mast cell activation directly via IL-4 receptor expression, or indirectly via upregulated immunoglobulin E (IgE) production. Dupilumab significantly improved CSU signs and symptoms in the phase 3, randomized, placebo-controlled LIBERTY-CSU CUPID Study A. This analysis explores the impact of dupilumab on CSU signs and symptoms and serum IgE levels in patients from LIBERTY-CSU CUPID Study A with serum total IgE above and below 100 IU/mL at baseline. Methods: Patients with H1-antihistamine-refractory CSU received dupilumab (n = 70) or placebo (n = 68) for 24 weeks. Efficacy endpoints were change from baseline to weeks 12 and 24 in serum total IgE levels, Itch Severity Score over 7 days (ISS7), Urticaria Activity Score over 7 days (UAS7), and Hives Severity Score over 7 days (HSS7) in dupilumab- or placebo-treated patients with serum total IgE above and below 100 IU/mL at baseline. Results: Dupilumab treatment significantly reduced median (interquartile range) IgE levels at week 12 [dupilumab: −31.9% (−41.9; −22.6); placebo: −6.3% (−21.3; 14.9)] and week 24 [dupilumab: −48.2% (−56.8; − 39.5); placebo: − 6.3% (−34.5; 14.8)]. Similar IgE reductions relative to baseline were observed in dupilumab-treated patients regardless of baseline IgE level. Dupilumab treatment improved ISS7, UAS7, and HSS7 over 12 and 24 weeks, regardless of baseline serum IgE level (interaction p ≥ 0.59 for all treatment by subgroup comparisons), with weak correlations (r < 0.2) observed between IgE level changes and ISS7, UAS7, and HSS7 outcomes. Conclusions: Dupilumab significantly improved CSU signs and symptoms and reduced serum IgE, regardless of baseline IgE levels. In the current analysis, baseline total IgE had no predictive value as a dupilumab treatment response biomarker in CSU. Downregulation of IgE, a key mediator of mast cell activation and histamine release, may at least partially explain the effectiveness of dupilumab in reducing CSU signs and symptoms. Trial Registration: ClinicalTrials.gov Identifier: NCT04180488. [ABSTRACT FROM AUTHOR]

Introduction: Kamebakaurin is an active constituent of both Rabdosia japonica and Rabdosia excisa, which are utilized in Chinese traditional medicine for improving symptoms in patients with allergies. We investigated the molecular mechanisms of the anti-allergic effects of kamebakaurin using BMMCs. Methods: The degranulation ratio, histamine release, and the interleukin (IL)-4, leukotriene B4 (LTB4), and cysteinyl leukotriene productions on antigen-triggered BMMC were investigated. Additionally, the effects of kamebakaurin on signal transduction proteins were examined by Western blot and binding to the Syk and Lyn kinase domain was calculated. The effects of kamebakaurin on antigen-induced hyperpermeability were investigated using mouse model. Results: At 10 μm, kamebakaurin partially inhibited degranulation, histamine release, and IL-4 production. At 30 μm, kamebakaurin partially reduced LTB4 and cysteinyl leukotriene productions and suppressed degranulation, histamine release, and IL-4 production. Phosphorylation of both Syk Y519/520 and its downstream protein, Gab2, was reduced by kamebakaurin, and complete inhibition was observed with 30 μm kamebakaurin. In contrast, phosphorylation of Erk was only partially inhibited, even in the presence of 30 μm kamebakaurin. Syk Y519/520 is known to be auto-phosphorylated via intramolecular ATP present in its own ATP-binding site, and this auto-phosphorylation triggers degranulation, histamine release, and IL-4 production. Docking simulation study indicated kamebakaurin blocked ATP binding to the ATP-binding site in Syk. Therefore, inhibition of Syk auto-phosphorylation by kamebakaurin binding to the Syk ATP-binding site appeared to cause a reduction of histamine release and IL-4 production. Kamebakaurin inhibited antigen-induced vascular hyperpermeability in a dose-dependent fashion but did not reduce histamine-induced vascular hyperpermeability. Conclusion: Kamebakaurin ameliorates allergic symptoms via inhibition of Syk phosphorylation; thus, kamebakaurin could be a lead compound for the new anti-allergic drug. [ABSTRACT FROM AUTHOR]

This article discusses the role of IL-33, an alarmin cytokine, in regulating mast cell responses during food allergy. The IL-33 receptor, ST2, is expressed on mast cells, and genetic variations in the IL-33/ST2 axis are associated with disease susceptibility. The study used a mouse model of food allergy and found that IL-33 is critical for inducing mast cell responses to food antigens. Mice lacking ST2 showed decreased diarrhea, mast cell accumulation, and mast cell activation compared to wild-type mice. The study also found that IL-4 plays a role in mediating mast cell responses, as treatment with IL-4 reversed the attenuated mast cell activation in ST2-deficient mice. These findings provide insights into the potential interplay between IL-33 and IL-4 in the treatment of allergic diseases. [Extracted from the article]

This article explores the association between chronic urticaria (CU) and serological biomarkers, as well as the effects of omalizumab (OMZ) treatment on these biomarkers. The study found that CU is linked to elevated concentrations of MMP9 and CCL18, which are involved in skin ECM degradation and basophil migration, respectively. OMZ treatment was found to decrease vascular endothelial growth factor (VEGF) levels and alter the homeostasis of type I, IV, and VI collagens. The study also observed changes in the concentration of extracellular vesicles (EVs) in CU patients after OMZ treatment. These findings suggest potential candidates for further research in CU management. [Extracted from the article]

Chronic spontaneous urticaria (CSU) is a debilitating, inflammatory skin condition characterized by infiltrating immune cells. Available treatments are limited to improving the signs and symptoms. There is an unmet need to develop therapies that target disease‐driving pathways upstream of mast cell activation to inhibit or delay the progression of CSU and associated comorbidities. Here, we aim to define disease modification due to a treatment intervention and criteria that disease‐modifying treatments (DMTs) must meet in CSU. We have defined disease modification in CSU as a favorable treatment‐induced change in the underlying pathophysiology and, therefore, the disease course, which is clinically beneficial and enduring. A DMT must fulfil the following criteria: (1) prevents or delays the progression of CSU, (2) induces long‐term, therapy‐free clinical remission, which is the sustained absence of CSU signs and symptoms without the need for treatment, and (3) affects the underlying mechanism of CSU, as demonstrated by an effect on disease‐driving signals and/or a biomarker. DMTs in CSU should slow disease progression, achieve long‐lasting disease remission, target disease‐driving mechanisms, reduce mast cell‐activating IgE autoantibodies, target cytokine profile polarization, and normalize the gut microbiome and barrier. Treating CSU at the immune system level could provide valuable alternatives to pharmacotherapy in CSU management. Specific DMTs in CSU are yet to be developed, but some show potential benefits, such as inhibitors of Bruton's Tyrosine Kinase, IL‐4 and IL‐13. Future therapies could prevent CSU signs and symptoms, achieve long‐term clinical benefits after discontinuing treatment, and prevent associated concomitant disorders. [ABSTRACT FROM AUTHOR]

Background: Galectin‐9 (Gal‐9) has been implicated in allergic and autoimmune diseases, but its role and relevance in chronic spontaneous urticaria (CSU) are unclear. Objectives: To characterize the role and relevance of Gal‐9 in the pathogenesis of CSU. Methods: We assessed 60 CSU patients for their expression of Gal‐9 on circulating eosinophils and basophils as well as T cell expression of the Gal‐9 receptor TIM‐3, compared them with 26 healthy controls (HCs), and explored possible links with disease features including disease activity (urticaria activity score, UAS), total IgE, basophil activation test (BAT), and response to omalizumab treatment. We also investigated potential drivers of Gal‐9 expression by eosinophils and basophils. Results: Our CSU patients had markedly increased rates of circulating Gal‐9+ eosinophils and basophils and high numbers of lesional Gal‐9+ cells. High rates of blood Gal‐9+ eosinophils/basophils were linked to high disease activity, IgE levels, and BAT negativity. Serum levels of TNF‐α were positively correlated with circulating Gal‐9+ eosinophils/basophils, and TNF‐α markedly upregulated Gal‐9 on eosinophils. CSU patients who responded to omalizumab treatment had more Gal‐9+ eosinophils/basophils than non‐responders, and omalizumab reduced blood levels of Gal‐9+ eosinophils/basophils in responders. Gal‐9+ eosinophils/basophils were negatively correlated with TIM‐3+TH17 cells. Conclusion: Our findings demonstrate a previously unrecognized involvement of the Gal‐9/TIM‐3 pathway in the pathogenesis CSU and call for studies that explore its relevance. [ABSTRACT FROM AUTHOR]

Derived from the myeloid lineage, granulocytes, including basophils, eosinophils, and neutrophils, along with mast cells, play important, often disparate, roles across the allergic disease spectrum. While these cells and their mediators are commonly associated with allergic inflammation, they also exhibit several functions either promoting or restricting tumor growth. In this Position Paper we discuss common granulocyte and mast cell features relating to immunomodulatory functions in allergy and in cancer. We highlight key mechanisms which may inform cancer treatment and propose pertinent areas for future research. We suggest areas where understanding the communication between granulocytes, mast cells, and the tumor microenvironment, will be crucial for identifying immune mechanisms that may be harnessed to counteract tumor development. For example, a comprehensive understanding of allergic and immune factors driving distinct neutrophil states and those mechanisms that link mast cells with immunotherapy resistance, might enable targeted manipulation of specific subpopulations, leading to precision immunotherapy in cancer. We recommend specific areas of investigation in AllergoOncology and knowledge exchange across disease contexts to uncover pertinent reciprocal functions in allergy and cancer and allow therapeutic manipulation of these powerful cell populations. These will help address the unmet needs in stratifying and managing patients with allergic diseases and cancer. [ABSTRACT FROM AUTHOR]

The article discusses the presence of mouse IgG antibodies in the widely used mouse IgE clone SPE-7, which is used to study IgE biology and function. The study found that SPE-7 contains IgG2a/b-IgE complexes, which can alter the functional profile of IgE. The presence of IgG in SPE-7 was confirmed through various assays, including enzyme-linked immunosorbent assays (ELISA) and liquid chromatography-mass spectrometry (LC-MS). These findings challenge the concept that IgE exerts antigen-independent effects on mast cell degranulation and survival. The study suggests that the presence of contaminating IgGs in therapeutic IgE antibodies should be considered, as they may alter the functional and pharmacological profile of these antibodies. [Extracted from the article]

Background: Hypersensitivity reactions (HR) are common in mastocytosis. However, little is known about triggers and risk factors. The registry of the European Competence Network on Mastocytosis (ECNM) enables reliable studies in a larger cohort of mastocytosis patients. We assessed prevalence, triggers and risk factors of HR in adults with mastocytosis in the ECNM registry. Methods: Data were collected in 27 ECNM centers. We analyzed potential triggers (Hymenoptera venoms, food, drug, inhalant and others) and risk factors at diagnosis and during follow‐up. The study group consisted of 2485 adults with mastocytosis, 1379 women (55.5%) and 1106 men (44.5%). Median age was 48.2 years (range 18–91 years). Results: Nine hundred and forty eight patients (38.1%) reported one or more HR'. Most common triggers were Hymenoptera venoms in cutaneous mastocytosis (CM) and indolent systemic mastocytosis (ISM), whereas in advanced SM (advSM), most common elicitors were drugs, including nonsteroidal anti‐inflammatory agents and penicillin. In multivariate analyses, tryptase level < 90 ng/mL, <15% infiltration by mast cells in bone marrow biopsy‐sections, and diagnosis of ISM were identified as independent risk factors for HR. For drug‐induced HR, prominent risk factors were advSM and high tryptase levels. New reactions were observed in 4.8% of all patients during 4 years follow‐up. Conclusions: HR are mainly triggered by Hymenoptera venoms in patients with CM and ISM and by drugs in patients with advSM. Tryptase levels <90 ng/mL, mast cell bone marrow infiltration <15%, and WHO category ISM are predictors of HR. New HR occur in 4.8% of all patients within 4 years. [ABSTRACT FROM AUTHOR]

Background: Chronic spontaneous urticaria (CSU) is a common, debilitating skin disorder characterized by recurring episodes of raised, itchy and sometimes painful wheals lasting longer than 6 weeks. CSU is mediated by mast cells which are absent from peripheral blood. However, lineage−CD34hiCD117int/hiFcεRI+ cells in blood have previously been shown to represent a mast cell precursor. Methods: We enumerated FcεRI−, FcεRI+ and FcεRIhi lineage−CD34+CD117+ cells using flow cytometry in blood of patients with CSU (n = 55), including 12 patients receiving omalizumab and 43 not receiving omalizumab (n = 43). Twenty‐two control samples were studied. Disease control and patient response to omalizumab was evaluated using the urticaria control test. We performed single‐cell RNA sequencing (scRNA‐Seq) on lineage−CD34hiCD117hi blood cells from a subset of patients with CSU (n = 8) and healthy controls (n = 4). Results: CSU patients had more lineage−CD34+CD117+FcεRI+ blood cells than controls. Lineage−CD34+CD117+FcεRI+ cells were significantly higher in patients with CSU who had an objective clinical response to omalizumab when compared to patients who had poor disease control 90 days after initiation of omalizumab. scRNA‐Seq revealed that lineage−CD34+CD117+FcεRI+ cells contained both lymphoid and myeloid progenitor lineages, with omalizumab responsive patients having proportionally more myeloid progenitors. The myeloid progenitor lineage contained small numbers of true mast cell precursors along with more immature FcεRI− and FcεRI+ myeloid progenitors. Conclusion: Increased blood CD34+CD117+FcεRI+ cells may reflect enhanced bone marrow egress in the setting of CSU. High expression of these cells strongly predicts better clinical responses to the anti‐IgE therapy, omalizumab. [ABSTRACT FROM AUTHOR]

Background: In patients who require venom immunotherapy (VIT), there is a need to identify underlying mast cell (MC) disorders since these may affect the risk and severity of future sting reactions and the long‐term effectiveness of VIT. Methods: 1319 individuals with Hymenoptera venom allergy (HVA) who needed VIT from referral centers in Slovenia, Austria, Croatia, and Poland underwent examination for KIT p.D816V in peripheral blood leukocytes (PBL) using a highly sensitive PCR test and tryptase genotyping by digital droplet PCR. We also included 183 control individuals with large local reactions (LLRs) to Hymenoptera stings and with asymptomatic sensitization to Hymenoptera venoms. Results: 285 of 1319 individuals recommended for VIT (21.6%) were positive for KIT p.D816V in PBL, preferably those who present with severe reaction (33.9% [n = 207 of 610] with Ring‐Messmer grade 3–4 vs. 11% [n = 78 of 709] with Grade 1–2; p <.0001), whereas only 1.3% (n = 2 of 152) of controls with LLR and none with asymptomatic sensitization (n = 31) had KIT p.D816V. KIT p.D816V allelic burden was higher in those with severe reaction (median 0.018% [n = 207] in Grade 3–4 vs. 0.001% [n = 78] in Grade 1–2; p <.0001), and the majority had normal baseline serum tryptase levels (69% [n = 196 of 285]). All KIT p.D816V‐positive individuals (n = 41) who underwent bone marrow (BM) biopsy were found to have underlying clonal diseases, principally BM mastocytosis. HαT was also associated with severe HVA and symptoms (p <.01), and remarkably, 31.0% (n = 31 of 100) were found to have concomitant KIT p.D816V. Concomitant HαT and KIT p.D816V showed an additive effect, and having both was associated with the highest risk for severe HVA, even higher than having either HαT or KIT p.D816V alone (OR = 3.8; p <.01). Conclusions: By employing prospective universal tryptase genotyping and examination for KIT p.D816V in PBL in large HVA populations, we have demonstrated a high burden of clonal MC disorders and HαT in patients who require VIT. [ABSTRACT FROM AUTHOR]

The gut–skin axis has recently been widely recognized, and both the gut and skin have been found to affect each other through a bidirectional connection; however, the precise mechanisms remain to be elucidated. Therefore, we aimed to investigate the effects of chronic skin damage (CSD) on mouse intestines. Following the CSD model, 4% sodium dodecyl sulfate was applied to the back-shaved murine skin six times for 2 weeks after tape stripping. The small and large intestines were analyzed histologically and immunologically, respectively. Intestinal permeability was measured using fluorescein isothiocyanate-conjugated-dextran. The role of interleukin-13 (IL-13) in the ileum was investigated using an anti-IL-13 antibody. Apoptotic intestinal cells were analyzed using TUNEL staining. Villus atrophy was observed in the small intestine in the CSD model, along with increased permeability. Mast cells, but not T cells, eosinophils, or innate lymph cell-2, were increased in the intestinal mucosa. However, no significant changes were observed in the large intestine. mRNA expression of IL-13 was increased only in the ileum of the CSD model. Apoptotic intestinal epithelial cells were significantly increased in the ileum of the CSD model. Administration of an anti-IL-13 antibody ameliorated the intestinal damage caused by CSD, along with decreased apoptotic cells and mast cell infiltration. Skin damage causes morphological changes in the small intestine, accompanied by increased intestinal permeability, possibly through the IL-13-induced apoptosis of mast cells in the epithelium. Surfactant-mediated mechanical skin damage can cause a leaky gut. Gut and skin have been found to affect each other through a bidirectional connection (gut–skin axis), though the precise mechanisms remain to be elucidated. In this study, surfactant-mediated mechanical chronic skin damage caused morphological changes in the small intestine of mice, accompanied by increased intestinal permeability, possibly through the interleukin-13-induced apoptosis of mast cells in the epithelium. Graphical Abstract [ABSTRACT FROM AUTHOR]

[Display omitted] • The immune response and inflammation in pulmonary hypertension (PH) have been systematically summarized based on recent studies. • The relationship between CC chemokines and the pathogenesis of pH is summarized in clinical and animal models. • We found that although the immune response serves as an important potential factor in the pathogenesis of PH, less attention has been paid to CC chemokines and their receptors. • We believe that a greater understanding of the relationship between PH and CC chemokines and their receptors is a pressing issue. • We believe that we need to further clarify the pathogenesis of pH and provide basis for the clinical treatment of PH. Pulmonary hypertension (PH) represents a progressive condition characterized by the remodeling of pulmonary arteries, ultimately culminating in right heart failure and increased mortality rates. Substantial evidence has elucidated the pivotal role of perivascular inflammatory factors and immune dysregulation in the pathogenesis of PH. Chemokines, a class of small secreted proteins, exert precise control over immune cell recruitment and functionality, particularly with respect to their migration to sites of inflammation. Consequently, chemokines emerge as critical drivers facilitating immune cell infiltration into the pulmonary tissue during inflammatory responses. This review comprehensively examines the significant contributions of CC chemokines in the maintenance of immune cell homeostasis and their pivotal role in regulating inflammatory responses. The central focus of this discussion is directed towards elucidating the precise immunoregulatory actions of CC chemokines concerning various immune cell types, including neutrophils, monocytes, macrophages, lymphocytes, dendritic cells, mast cells, eosinophils, and basophils, particularly in the context of pH processes. Furthermore, this paper delves into an exploration of the underlying pathogenic mechanisms that underpin the development of PH. Specifically, it investigates processes such as cellular pyroptosis, examines the intricate crosstalk between bone morphogenetic protein receptor type 2 (BMPR2) mutations and the immune response, and sheds light on key signaling pathways involved in the inflammatory response. These aspects are deemed critical in enhancing our understanding of the complex pathophysiology of PH. Moreover, this review provides a comprehensive synthesis of findings from experimental investigations targeting immune cells and CC chemokines. Aim of review : In summary, the inquiry into the inflammatory responses mediated by CC chemokines and their corresponding receptors, and their potential in modulating immune reactions, holds promise as a prospective avenue for addressing PH. The potential inhibition of CC chemokines and their receptors stands as a viable strategy to attenuate the inflammatory cascade and ameliorate the pathological manifestations of PH. Nonetheless, it is essential to acknowledge the current state of clinical trials and the ensuing progress, which regrettably appears to be less than encouraging. Substantial hurdles exist in the successful translation of research findings into clinical applications. The intention is that such emphasis could potentially foster the advancement of potent therapeutic agents presently in the process of clinical evaluation. This, in turn, may further bolster the potential for effective management of PH. [ABSTRACT FROM AUTHOR]

IgE-mediated degranulation of mast cells (MCs) provides rapid protection against environmental hazards, including animal venoms. A fraction of tissue-resident MCs intimately associates with blood vessels. These perivascular MCs were reported to extend projections into the vessel lumen and to be the first MCs to acquire intravenously injected IgE, suggesting that IgE loading of MCs depends on their vascular association. We sought to elucidate the molecular basis of the MC–blood vessel interaction and to determine its relevance for IgE-mediated immune responses. We selectively inactivated the Itgb1 gene, encoding the β1 chain of integrin adhesion molecules (ITGB1), in MCs by conditional gene targeting in mice. We analyzed skin MCs for blood vessel association, surface IgE density, and capability to bind circulating antibody specific for MC surface molecules, as well as in vivo responses to antigen administered via different routes. Lack of ITGB1 expression severely compromised MC–blood vessel association. ITGB1-deficient MCs showed normal densities of surface IgE but reduced binding of intravenously injected antibodies. While their capacity to degranulate in response to IgE ligation in vivo was unimpaired, anaphylactic responses to antigen circulating in the vasculature were largely abolished. ITGB1-mediated association of MCs with blood vessels is key for MC immune surveillance of blood vessel content, but is dispensable for slow steady-state loading of endogenous IgE onto tissue-resident MCs. [ABSTRACT FROM AUTHOR]

The specific detection of serum IgE antibodies specific to allergens (sIgE Abs) that can crosslink the plural high-affinity IgE receptor (FcεRIα) molecules on the surface of mast cells or basophils with a multivalent allergen can reduce the false-positive diagnoses observed in chemiluminescent and fluorescence enzyme immunoassays for type-I allergic patients. In this study, we detected sIgE Abs to the egg-allergen ovalbumin (OVA) and the wheat-allergen gluten in the sera of rats sensitized with each allergen using an amplified luminescence proximity homogeneous assay by crosslinking (AlphaCL). OVA and gluten were reacted with each sIgE Ab in the sera. Then, acceptor and donor beads labeled with the human FcεRIα were added to the reacted solution. The luminescence intensity for anti-OVA IgE Abs in the sera with the removal of IgG Abs was observed in five of seven (71.4%) of the sensitized rats, whereas no signals were observed in any of the unsensitized rats. The AlphaCL could also detect anti-gluten sIgE Abs in the sera of sensitized rats, but not of unsensitized rats. In conclusion, we successfully detected sIgE Abs in the sera of rats sensitized to two allergens using the AlphaCL. This detection method has the potential to be used as a new diagnostic tool for type-I allergic patients. [ABSTRACT FROM AUTHOR]

Whether N6‐Methyladenosine (m6A)‐ and ferroptosis‐related genes act on immune responses to regulate glioma progression remains unanswered. Data of glioma and corresponding normal brain tissues were fetched from the TCGA database and GTEx. Differentially expressed genes (DEGs) were identified for GO and KEGG enrichment analyses. The FerrDb database was based to yield ferroptosis‐related DEGs. Hub genes were then screened out using the cytoHubba database and validated in clinical samples. Immune cells infiltrating into the glioma tissues were analysed using the CIBERSORT R script. The association of gene signature underlying the m6A‐related ferroptosis with tumour‐infiltrating immune cells and immune checkpoints in low‐grade gliomas was analysed. Of 6298 DEGs enriched in mRNA modifications, 144 were ferroptosis‐related; NFE2L2 and METTL16 showed the strongest positive correlation. METTL16 knockdown inhibited the migrative and invasive abilities of glioma cells and induced ferroptosis in vitro. NFE2L2 was enriched in the anti‐m6A antibody. Moreover, METTL16 knockdown reduced the mRNA stability and level of NFE2L2 (both p < 0.05). Proportions of CD8+ T lymphocytes, activated mast cells and M2 macrophages differed between low‐grade gliomas and normal tissues. METTL16 expression was negatively correlated with CD8+ T lymphocytes, while that of NFE2L2 was positively correlated with M2 macrophages and immune checkpoints in low‐grade gliomas. Gene signatures involved in the m6A‐related ferroptosis in gliomas were identified via bioinformatic analyses. NFE2L2 interacted with METTL16 to regulate the immune response in low‐grade gliomas, and both molecules may be novel therapeutic targets for gliomas. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This document is a research paper discussing the diagnosis of hypersensitivity to amoxicillin, a type of beta-lactam antibiotic. The authors conducted a study using a test called hMC-pMAT to evaluate its effectiveness in diagnosing amoxicillin hypersensitivity. The results showed that hMC-pMAT was comparable to other diagnostic tests, such as the basophil activation test (BAT), in clear cases of hypersensitivity. However, in more difficult cases and in patients with non-responsive basophils, hMC-pMAT did not provide additional value. The authors suggest that further research is needed to validate and generalize these findings, especially for patients with non-responsive basophils. [Extracted from the article]

Melasma is an acquired chronic pigmentary disorder affecting millions of individuals worldwide. However, the pathogenesis of melasma remains unclear. This article provides a comprehensive review of the pathophysiological changes occurring in the skin microenvironment of melasma lesions, which can be summarized as follows: (1) skin barrier dysfunction and abnormal synthesis, transport, and intracellular distribution of melanin in the epidermis; (2) basement membrane damage; (3) solar elastosis, vascular changes, senescent fibroblasts, mast cell infiltration, and sebocyte participation in the dermis; and (4) systemic factors such as sex hormones and oxidative stress. Furthermore, potential therapeutic strategies are introduced to provide novel perspectives for fundamental and clinical research related to melasma. [ABSTRACT FROM AUTHOR]

Type I hypersensitivity, also known as classical allergy, is mediated via allergen‐specific IgE antibodies bound to type I FcR (FcεRI) on the surface of mast cells and basophils upon cross‐linking by allergens. This IgE‐mediated cellular activation may be blocked by allergen‐specific IgG through multiple mechanisms, including direct neutralization of the allergen or engagement of the inhibitory receptor FcγRIIb which blocks IgE signal transduction. In addition, co‐engagement of FcεRI and FcγRIIb by IgE‐IgG‐allergen immune complexes causes down regulation of receptor‐bound IgE, resulting in desensitization of the cells. Both, activation of FcεRI by allergen‐specific IgE and engagement of FcγRIIb by allergen‐specific IgG are driven by allergen‐binding. Here we delineate the distinct roles of antibody affinity versus avidity in driving these processes and discuss the role of IgG subclasses in inhibiting basophil and mast cell activation. [ABSTRACT FROM AUTHOR]

Background Hypothesis Animals Methods Results Conclusions and Clinical Importance Bronchoalveolar lavage (BAL) is a common procedure for evaluation of the equine lower airways. Time to resolution of post‐BAL inflammation has not been clearly defined.Residual inflammation, evident by changes in immune cell populations and inflammatory cytokines, will resolve by 72 hours after BAL.Six adult, healthy, institution‐owned horses.Randomized, complete cross‐over design. Each horse underwent 3 paired BALs, including a baseline and then 48, 72, and 96 hours later, with a 7‐day washout between paired BALs. Each sample underwent cytological evaluation and cytokine concentrations were determined by a commercially available multiplex bead immunoassay. Statistical analysis was performed by multilevel mixed‐effects Poisson regression analysis. Data are reported as marginal means and 95% confidence interval (CI).Neutrophil, eosinophil and mast cell percentages were not significantly different at any time points. Macrophage percentages were higher at 72 hours (45.0 [95% CI, 41.6‐48.4]%) and 96 hours (45.3 [95% CI, 42.9‐47.7]%) vs baseline (37.4 [95% CI, 33.5‐41.4]%; P < .001 and P = .01, respectively), and at 72 hours and 96 hours vs 48 hours (31.9 [95% CI, 28.1‐35.6]%; P < .001). Neutrophil percentage was not significantly increased at 48 hours (P = .11). Interleukin (IL)‐6 concentration was increased at 72 hours (5.22 [95% CI, 3.44‐6.99] pg/mL) vs 48 hours (4.38 [95% CI, 2.99‐5.78] pg/mL; P < .001).Significant lung inflammation was not detected at 72 and 96 hours, suggesting that repeating BAL at 72 hours or more can be done without concern of residual inflammation. [ABSTRACT FROM AUTHOR]

Rationale: Food allergy is a prevalent disease in the U.S., affecting nearly 30 million people. The primary management strategy for this condition is food avoidance, as limited treatment options are available. The elevation of pathologic IgE and over-reactive mast cells/basophils is a central factor in food allergy anaphylaxis. This study aims to comprehensively evaluate the potential therapeutic mechanisms of a small molecule compound called formononetin in regulating IgE and mast cell activation. Methods: In this study, we determined the inhibitory effect of formononetin on the production of human IgE from peripheral blood mononuclear cells of food-allergic patients using ELISA. We also measured formononetin's effect on preventing mast cell degranulation in RBL-2H3 and KU812 cells using betahexosaminidase assay. To identify potential targets of formononetin in IgE-mediated diseases, mast cell disorders, and food allergies, we utilized computational modeling to analyze mechanistic targets of formononetin from various databases, including SEA, Swiss Target Prediction, PubChem, Gene Cards, and Mala Cards. We generated a KEGG pathway, Gene Ontology, and Compound Target Pathway Disease Network using these targets. Finally, we used qRT-PCR to measure the gene expression of selected targets in KU812 and U266 cell lines. Results: Formononetin significantly decreased IgE production in IgE-producing human myeloma cells and PBMCs from food-allergic patients in a dose-dependent manner without cytotoxicity. Formononetin decreased betahexosaminidase release in RBL-2H3 cells and KU812 cells. Formononetin regulates 25 targets in food allergy, 51 in IgE diseases, and 19 in mast cell diseases. KEGG pathway and gene ontology analysis of targets showed that formononetin regulated disease pathways, primary immunodeficiency, Epstein- Barr Virus, and pathways in cancer. The biological processes regulated by formononetin include B cell proliferation, differentiation, immune response, and activation processes. Compound target pathway disease network identified NFKB1, NFKBIA, STAT1, STAT3, CCND1, TP53, TYK2, and CASP8 as the top targets regulated at a high degree by formononetin. TP53, STAT3, PTPRC, IL2, and CD19 were identified as the proteins mostly targeted by formononetin. qPCR validated genes of Formononetin molecular targets of IgE regulation in U266 cells and KU812 cells. In U266 cells, formononetin was found to significantly increase the gene expression of NFKBIA, TP53, and BCL-2 while decreasing the gene expression of BTK TYK, CASP8, STAT3, CCND1, STAT1, NFKB1, IL7R. In basophils KU812 cells, formononetin significantly increased the gene expression of NFKBIA, TP53, and BCL-2 while decreasing the gene expression of BTK, TYK, CASP8, STAT3, CCND1, STAT1, NFKB1, IL7R. Conclusion: These findings comprehensively present formononetin's mechanisms in regulating IgE production in plasma cells and degranulation in mast cells. [ABSTRACT FROM AUTHOR]

Leukocyte cell-derived chemotaxin 2 (LECT2) is linked to various immune diseases. Previously, we reported that serum LECT2 levels correlate with disease severity in atopic dermatitis (AD) patients. To investigate the role of LECT2 in AD and elucidate its potential mechanisms, we used LECT2 to treat an ADmouse model induced by 1-Chloro-2,4-dinitrobenzene (DNCB) in LECT2 knockout (KO) and wild-type (WT) mice, and an AD cell model using TNF-α/IFN-γ-induced HaCaT cells. Inflammatory factors and barrier proteins were analyzed by histology, immunohistochemistry, RT-qPCR, ELISA, and Western Blot. Activation of the NFkB signaling pathway was evaluated by Western Blot and immunofluorescence. In the ADmouse model, LECT2 treatment increased epidermal and dermal thickness, mast cell infiltration, and downregulated barrier proteins. Inflammatory factors were increased in skin lesions and serum. In the AD cell model, LECT2 decreased barrier protein levels and increased inflammatory factor levels, enhancing NF-κB P65 nuclear translocation. These results indicate that LECT2 exacerbates AD-like responses by dysregulating the NF-κB signaling pathway, highlighting its potential as a therapeutic target for AD management. [ABSTRACT FROM AUTHOR]

Introduction: The Janus kinase (JAK) family includes four cytoplasmic tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) constitutively bound to several cytokine receptors. JAKs phosphorylate downstream signal transducers and activators of transcription (STAT). JAK-STAT5 pathways play a critical role in basophil and mast cell activation. Previous studies have demonstrated that inhibitors of JAK-STAT pathway blocked the activation of mast cells and basophils. Methods: In this study, we investigated the in vitro effects of ruxolitinib, a JAK1/2 inhibitor, on IgE- and IL-3-mediated release of mediators from human basophils, as well as substance P-induced mediator release from skin mast cells (HSMCs). Results: Ruxolitinib concentration-dependently inhibited IgE-mediated release of preformed (histamine) and de novo synthesized mediators (leukotriene C4) from human basophils. Ruxolitinib also inhibited anti-IgE- and IL-3-mediated cytokine (IL-4 and IL-13) release from basophils, as well as the secretion of preformed mediators (histamine, tryptase, and chymase) from substance Pactivated HSMCs. Discussion: These results indicate that ruxolitinib, inhibiting the release of several mediators from human basophils and mast cells, is a potential candidate for the treatment of inflammatory disorders. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the histopathological effects of obstetric gel (OG) on vaginal tissue. In this study, 21 female Wistar albino rats were divided into three groups, comprising seven animals in each group. The first group (group 1) was the control group, the second group (group 2) was the physiological saline (PS) group, and the third group (group 3) was the OG group. In group 1, dilatation was performed using Hegar dilators from Hegar 5 to Hegar 10 without any vaginal application. In group 2, the vagina was washed with a PS-filled applicator. In group 3, the vagina was washed with an OG-filled applicator and Hegar dilators were used to achieve vaginal dilatation. In the group of OG-applied rats, there was an increase in mast cell infiltration, tissue epithelial thickness, and fibrillin-1 levels of the mucosa in the vaginal tissue. The present study is the first to investigate the histopathological effects of OG used for vaginal tissue dilatation in rats. OGs have no early effectiveness in preventing the damage caused by compression of the vaginal wall; however, OGs may have a protective effect against pelvic floor pathologies. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion The field of drug development is witnessing a remarkable surge in the development of innovative strategies. There is a need to develop technological platforms capable of generating human data prior to progressing to clinical trials.Here we introduce a new flexible solution designed for the comprehensive monitoring of the natural human skin ecosystem's response to immunogenic drugs over time. Based on unique bioengineering to preserve surgical resections in a long survival state, it allows for the first time a comprehensive analysis of resident immune cells response at both organ and single‐cell levels.Upon injection of the mRNA‐1273 COVID‐19 vaccine, we characterized precise sequential molecular events triggered upon detection of the exogenous substance. The vaccine consistently targets DC/macrophages and mast cells, regardless of the administration route, while promoting specific cell–cell communications in surrounding immune cell subsets.Given its direct translational relevance, this approach provides a multiscale vision of genuine human tissue immunity that could pave the way toward the development of new vaccination and drug development strategies. [ABSTRACT FROM AUTHOR]

Allergies are one of the diseases whose incidence rates have increased in recent years due to the greenhouse effect and extreme climate change. Therefore, the development of new antiallergic drugs has attracted the interest of researchers in chemistry and pharmacy fields. Dicoumarin is a coumarin derivative with various biological activities, but its antiallergic activity has not been evaluated. In this study, 14 different dicoumarin derivatives were synthesized by diethylamine-catalyzed condensation reactions of 4-hydroxycoumarin with 14 different aldehydes, and they were identified on the basis of their spectral data. The dicoumarin derivatives were subjected to studies on the degranulation of rat basophilic leukemia cells (RBL-2H3 cells) and mouse bone-marrow-derived mast cells (mBMMCs), and some of them showed good inhibitory effects on the degranulation of the two types of mast cells, demonstrating their good antiallergic activity. This study presents a new method of developing new antiallergic drugs. [ABSTRACT FROM AUTHOR]

Burn injuries represent a significant problem in clinical practice due to the high risk of infection and the prolonged healing process. Recently, more attention has been given to natural remedies such as water extracts of various medicinal plants, which possess anti-inflammatory and wound healing properties. The aim of this study is to evaluate the efficacy and safety of Satureja montana L. and other water extracts in a burn wound model. The study involved male Californian rabbits (n = 52) divided into eight groups. Burn wounds were modeled on the animals and subsequently treated with gels based on Satureja montana L. and other water extracts. The reparative potential of the epidermis (assessed by Ki-67 expression), the state of local immunity (measured by the number of CD-45 cells), and the anti-inflammatory role of mast cells (measured by tryptase levels) were evaluated. Bacteriological and morphological studies were conducted. The most pronounced bactericidal, reparative, and immunostimulatory effects were observed after the treatment using a gel mixture of water extracts from Satureja montana L., Salvia sclarea, Coriandrum sativum L., and Lavandula angustifolia in equal proportions (1:1:1:1). The other gels also demonstrated high efficacy in treating burn wounds, especially when using a strain of Pseudomonas aeruginosa resistant to several antibiotics. Immunohistochemical studies showed a significant increase in the number of Ki-67-positive cells in the basal layer of the epidermis and a decrease in the number of CD-45-positive cells, indicating improved proliferative activity and reduced inflammation. This study confirms the hypothesis that the use of water extract mixtures significantly enhances the reparative potential, improves the immune response in the treatment of burns, and promotes wound healing. These findings pave the way for further research and the application of complex phytotherapeutic agents, specifically water extracts of medicinal plants containing phenols and antioxidants in burn wound therapy. [ABSTRACT FROM AUTHOR]