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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.

Background: Mast cells (MCs) are tissue resident cells of the immune system, mainly known for their role in allergy. However, mounting evidence indicates their involvement in the pathology of age-related diseases, such as Alzheimer's disease, Parkinson's disease, and cancer. MC numbers increase in aged tissues, but how ageing affects MCs is poorly understood. Results: We show that MC ageing is associated with the increased expression of the cell cycle inhibitor p16 Ink4a, a marker and inducer of cellular senescence. Relying on this observation and the tight association of ageing with senescence, we developed a model of inducible senescence based on doxycycline-induced expression of p16Ink4a in cultured bone marrow derived MCs (BMMCs). Using this model, we show that senescent MCs upregulate IL-1β, TNF-α and VEGF-A. We also demonstrate that senescence causes marked morphological changes that impact MC function. Senescent MCs are larger, contain a larger number of secretory granules (SGs) and have less membrane protrusions. Particularly striking are the changes in their SGs, reflected in a significant reduction in the number of electron dense SGs with a concomitant increase in lucent SGs containing intraluminal vesicles. The changes in SG morphology are accompanied by changes in MC degranulation, including a significant increase in receptor-triggered release of CD63-positive extracellular vesicles (EVs) and the exteriorisation of proteoglycans, as opposed to a gradual inhibition of the release of β-hexosaminidase. Conclusions: The inducible expression of p16Ink4a imposes MC senescence, providing a model for tracking the autonomous changes that occur in MCs during ageing. These changes include both morphological and functional alterations. In particular, the increased release of small EVs by senescent MCs suggests an enhanced ability to modulate neighbouring cells. [ABSTRACT FROM AUTHOR]

ABSTRACT Canine mast cell tumours (MCTs) are one of the most common skin cancers of dogs. Surgical removal is the primary treatment, but recurrence and metastasis can occur even with low‐grade tumours. As a result, new treatment strategies are being sought. We tested the potential of several oncolytic viruses (OVs) to infect and kill a cell line isolated from a canine MCT. Employing a resazurin‐based metabolic assay and flow cytometry technology, we used recombinant vesicular stomatitis virus (rVSV‐Δm51), avian orthoavulavirus‐1 (AOaV‐1), and Orf viruses in our assessment. Our study aimed to evaluate the potential of oncolytic virotherapy in treating canine cancers. We found that MCT‐1 cells showed different sensitivities to the OVs, with rVSV‐Δm51 showing the most promising results in vitro. These findings suggest that further investigation into using OVs for treating canine MCTs is needed, although clinical efficacy is yet to be determined. [ABSTRACT FROM AUTHOR]

Background: Lung adenocarcinoma (LUAD) accounts for the highest proportion of lung cancers; however, specific biomarkers are lacking for diagnosis, treatment, and prognostic assessment. Cell division cycle-associated 8 (CDCA8) is a cell cycle regulator with elevated expression in various cancers. However, the association between CDCA8 expression and LUAD prognosis remains unclear. Methods: The association between CDCA8 and LUAD prognosis was evaluated based on the The Cancer Genome Atlas (TCGA) dataset, and CDCA8 related functions were determined using gene enrichment and gene ontology analyses. We also analyzed the association between CDCA8 expression and immune cell infiltration. Immunohistochemistry was used to determine the differential expression of CDCA8 in tumors and controls. Finally, we evaluated the differences in the sensitivity of different levels of CDCA8 to different anticancer drugs in LUAD. Results: CDCA8 expression was significantly higher in primary LUAD tumors than in normal tissues (P < 0.001). Moreover, Kaplan–Meier survival analysis demonstrated that high CDCA8 expression predicted poor survival in patients with LUAD (P = 0.006). The receiver operating characteristic (ROC) curves indicated that CDCA8 was an effective guide for the diagnosis of LUAD. Functional annotation indicated that CDCA8 might be involved in functions such as p53 stabilization, nucleotide metabolism, RNA-mediated gene silencing, and the G2/M phase checkpoint. Immune infiltration results suggested that CDCA8 was positively correlated with Th2 cells and Tgd and negatively correlated with Eosinophils and Mast cells (P < 0.01). In addition, elevated expression of CDCA8 may increase the sensitivity of patients to certain anticancer drugs. Conclusions: CDCA8 upregulation is significantly associated with poor survival and immune infiltration in patients with LUAD. Our study suggests that CDCA8 can be used as a biomarker for LUAD prognosis and a reference for personalized medication. [ABSTRACT FROM AUTHOR]

Background: Many patients experience persistent symptoms after COVID-19, a syndrome referred to as Long COVID (LC). The goal of this study was to identify novel new or worsening comorbidities self-reported in patients with LC. Methods: Patients diagnosed with LC (n = 732) at the Mayo Long COVID Care Clinic in Rochester, Minnesota and Jacksonville, Florida were sent questionnaires to assess the development of new or worsening comorbidities following COVID-19 compared to patients with SARS-CoV-2 that did not develop LC (controls). Both groups were also asked questions screening for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), generalized joint hypermobility (GJH) and orthostatic intolerance. 247 people with LC (33.7%) and 40 controls (50%) responded to the surveys. Results: In this study LC patients averaged 53 years of age and were predominantly White (95%) women (75%). The greatest prevalence of new or worsening comorbidities following SARS-CoV-2 infection in patients with LC vs. controls reported in this study were pain (94.4% vs. 0%, p < 0.001), neurological (92.4% vs. 15.4%, p < 0.001), sleep (82.8% vs. 5.3%, p < 0.001), skin (69.8% vs. 0%, p < 0.001), and genitourinary (60.6% vs. 25.0%, p = 0.029) issues. 58% of LC patients screened positive for ME/CFS vs. 0% of controls (p < 0.001), 27% positive for GJH compared to 10% of controls (p = 0.026), and a positive average score of 4.0 on orthostatic intolerance vs. 0 (p < 0.001). The majority of LC patients with ME/CFS were women (77%). Conclusion: We found that comorbidities across 12 surveyed categories were increased in patients following SARS-CoV-2 infection. Our data also support the overlap of LC with ME/CFS, GJH, and orthostatic intolerance. We discuss the pathophysiologic, research, and clinical implications of identifying these conditions with LC. [ABSTRACT FROM AUTHOR]

Mast cells (MCs) are tissue-resident cells of hematopoietic origin that play an important role in host's defense mechanism against nematodes. However, excessive activation of these cells contributes to the development of certain allergic diseases. Immunoglobin E (IgE) is one of the well-known molecules that activate MCs. Even in the absence of specific antigens, the binding of highly cytokinergic IgE to FcεRI on MCs prolongs their survival and induces cytokine production without enhancing their degranulation. In the present study, we examined the effects of the members of the interleukin-10 (IL-10) family of cytokines on IgE-mediated MCs functions. The receptors including Il10r1, Il10r2, and Il20r2, but not Il20r1, Il22r1 or Il28r1, were constitutively expressed in mouse bone marrow cell-derived cultured MCs (BMCMCs), suggesting that IL-10 may influence MCs function. Indeed, we found that only IL-10 could influence upon BMCMCs function; IL-10 enhanced prolongation of survival, promoted IL-6 and/or IL-13 production dependently of STAT1 and STAT3, and suppressed tumor necrosis factor production independently of STAT1 and STAT3 on IgE-stimulated BMCMCs. Moreover, the IL-10-mediated enhancement of IL-6 production by IgE-stimulated BMCMCs promotes Th17 cell expansion. These results suggest that IL-10 has a dual role as an anti-inflammatory and pro-inflammatory cytokine in MCs functions. [ABSTRACT FROM AUTHOR]

The article discusses the assessment of IgE and basophil activity in blood samples from nonhuman primates, specifically cynomolgus monkeys, in the context of developing new drugs to combat allergies. The study compares IgE biology between humans and cynomolgus monkeys, finding similarities in key residues and binding affinities for FcεRI. The research suggests that cynomolgus monkeys could serve as a relevant model for testing novel anti-IgE therapies, with potential applications in drug development and clinical trials. [Extracted from the article]

In this study, a set of spiro[5,8-methanoquinazoline-2,3′-indoline]-2′,4-dione derivatives 3a–p were synthesized starting from unsubstituted and N-methyl-substituted diendo- and diexo-2-aminonorbornene carboxamides, as well as various substituted isatins. The typical method involves a condensation reaction of alicyclic aminocarboxamide and isatin in the presence of a catalyst, using a solvent and an acceptable temperature. We developed a cost-effective and ecologically benign high-speed ball milling (HSBM), microwave irradiation (MW), and continuous flow (CF) technique to synthesize spiroquinazolinone molecule 3a. The structures of the synthesized compounds 3a–p were determined using 1D and 2D NMR spectroscopies. Furthermore, docking studies and absorption, distribution, metabolism, and toxicity (ADMET) predictions were used in this work. In agreement with the corresponding features found in the case of both the SARS-CoV-2 main protease (RCSB Protein Data Bank: 6LU7) and human mast cell tryptase (RCSB Protein Data Bank: 2ZA5) based on the estimated total energy and binding affinity, H bonds, and hydrophobicity in silico, compound 3d among our 3a–g, 3i–k, and 3m derivatives was found to be our top-rated compound. [ABSTRACT FROM AUTHOR]

Introduction: Anaphylaxis 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. Methods: 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). Results: 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. Discussion: 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]

Introduction: Novel 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. Methods: 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. Results: 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. Discussion: 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]

Simple Summary: Inhibitors of Bruton's tyrosine kinase (BTK) have changed how we treat chronic lymphocytic leukemia (CLL), a B cell malignancy. These inhibitors are known for blocking signals in B cells that help cancers derived from these immune cells grow, but they also have important effects on the non-malignant immune system. This work explains how BTK inhibitors influence different components of the immune system, such as B cells, T cells, and macrophages. It also reviews their impact on the generation of immune-signaling molecules or their effect on the tumor microenvironment. We also explored how these effects might be useful in treating autoimmune diseases and infections. By understanding how BTK inhibitors can impact cancer cells and the immune system, this paper highlights the potential for these drugs to be used in a wider range of medical conditions. Bruton's tyrosine kinase (BTK), a cytoplasmic tyrosine kinase, plays a pivotal role in B cell biology and function. As an essential component of the B cell receptor (BCR) signaling pathway, BTK is expressed not only in B cells but also in myeloid cells, including monocytes/macrophages, dendritic cells, neutrophils, and mast cells. BTK inhibitors (BTKis) have revolutionized the treatment of chronic lymphocytic leukemia (CLL) and other B cell malignancies. Besides their well-characterized role in inhibiting BCR signaling, BTKis also exert significant immunological influences outside the tumor cell that extend their therapeutic potential and impact on the immune system in different ways. This work elucidates the immunomodulatory mechanisms associated with BTK inhibition, focusing on CLL and other clinical contexts. We discuss how BTK inhibition affects various immune cells, including B cells, T cells, and macrophages. The effects of BTKis on the profiles of cytokines, also fundamental parts of the tumor microenvironment (TME), are summarized here as well. This review also appraises the implications of these immunomodulatory actions in the management of autoimmune diseases and infections. Summarizing the dual role of BTK inhibition in modulating malignant lymphocyte and immune cell functions, this paper highlights the broader potential clinical use of compounds targeting BTK. [ABSTRACT FROM AUTHOR]

During the active phase of urticaria, a decrease in peripheral blood basophils, known as basopenia, is observed. We previously reported that basopenia occurs as a result of basophils migrating to the skin in a contact dermatitis model where a Th2 response is induced with oxazolone. Although there is currently no established model for urticaria, given that urticaria is an IgE-mediated immediate-type allergic reaction, we aimed to determine whether an IgE-mediated model could reproduce the decrease in basophils in peripheral blood observed during the active phase of urticaria. Mice were pretreated with 2,4,6-trinitrophenylhaptene (TNP)-specific IgE and basophil dynamics were examined following stimulation with TNP-ovalbumin. Mast cell-deficient WBB6F1- Kit W /Kit W-v mice were used to investigate the role of mast cells in this IgE-mediated model. Following stimulation, we observed immediate ear swelling and basopenia after 0.5 hours. However, the number of basophils observed in the skin lesions was low, while a higher number of basophils were observed in the antigen-draining lymph nodes (LN). In mast cell-deficient mice, no increase in basophils in the LN was observed, reflecting reduced antigen influx into the LN, but basophils remained in the skin. In the IgE-mediated mouse model, basopenia was observed, which coincided with the induction of inflammation in the skin. The migration of basophils to the LN in this model suggests that the systemic immune system, including the LN, should be considered when exploring the pathogenesis of urticaria in humans. • Peripheral basopenia during active urticaria was verified using a mouse model. • IgE-mediated stimulation induces immediate skin swelling and peripheral basopenia. • IgE-sensitized basophils migrate to the antigen-draining lymph nodes. • Peripheral basophils decrease upon stimulation even in the absence of mast cells. • Without mast cells, antigen and basophil entry into lymph nodes are both suppressed. [ABSTRACT FROM AUTHOR]

Background: 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. Methods: 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. Results: 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. Conclusions: 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]

The article discusses the prevalence of hereditary alpha‐tryptasemia (HαT) in pediatric mastocytoma patients. The study included 90 patients with mastocytosis, with 7.8% of them having HαT. The prevalence of HαT was significantly higher in patients with mastocytoma compared to other subtypes of cutaneous mastocytosis. The presence of HαT did not increase the risk of anaphylaxis in pediatric patients, and further research is needed to understand the link between HαT and mastocytoma. [Extracted from the article]

Background: Injuries to the glenoid labrum have been recognized as a source of joint pain and discomfort, which may be associated with the inflammatory responses that lead to the deterioration of labral tissue. However, it is unclear whether the torn labrum prompts mast cell (MC) activation, resulting in synovial inflammatory responses that lead to labral tissue degeneration. Purpose: To determine the potential influence of activated MC on synovial inflammatory responses and subsequent labral tissue degeneration and shoulder function deterioration in a rat model by monitoring MC behavior and sequential inflammatory responses within the synovial tissue and labral tissue after injury, suture repair, and MC stabilizer administration. Study Design: Controlled laboratory study. Methods: Anteroinferior glenoid labral tears were generated in the right shoulder of rats (n = 20) and repaired using a tunneled suture technique. Synovial tissue inflammatory responses were modulated in some rats with intraperitoneal administration of an MC stabilizer—cromolyn (n = 10). At weeks 1 and 3, MC activation, synovial inflammatory responses, and labral degeneration were histologically evaluated. Simultaneously, gait analysis was performed before and after surgical repair to assess the worsening of the shoulder function after the injury and treatment. Results: Resident MC degranulation after labral injury (50.48% ± 8.23% activated at week 1) contributed to the initiation of synovial tissue inflammatory cell recruitment, inflammatory product release, matrix metalloproteinase-13, and subsequent labral tissue extracellular matrix degeneration. The administration of cromolyn, an MC stabilizer, was found to significantly diminish injury-mediated inflammatory responses (inflammatory cell infiltration and subsequent proinflammatory product secretion) and improve shoulder functional recovery. Conclusion: MC activation is responsible for labral tear–associated synovial inflammation and labral degeneration. The administration of cromolyn can significantly diminish the cascade of inflammatory reactions after labral injury. Clinical Relevance: Our findings support the concept that MC stabilizers may be used as a complementary therapeutic option in the treatment and repair of labral tears. [ABSTRACT FROM AUTHOR]

Chronic wounds significantly burden health care systems worldwide, requiring novel strategies to ease their impact. Many physiological processes underlying wound healing are well studied but the role of mast cells remains controversial. Mast cells are innate immune cells and play an essential role in barrier function by inducing inflammation to defend the host against chemical irritants and infections, among others. Many mast cell–derived mediators have proposed roles in wound healing; however, in vivo evidence using mouse models has produced conflicting results. Recently, studies involving more complex wound models such as infected wounds, diabetic wounds and wounds healing under psychological stress suggest that mast cells play critical roles in these processes. This review briefly summarizes the existing literature regarding mast cells in normal wounds and the potential reasons for the contradictory results. Focus will be placed on examining more recent work emerging in the last 5 years that explores mast cells in more complex systems of wound healing, including infection, psychological stress and diabetes, with a discussion of how these discoveries may inspire future work in the field. [ABSTRACT FROM AUTHOR]

Mast cells are commonly found in pancreatic ductal adenocarcinoma (PDAC), yet their role in the disease remains uncertain. Although mast cells have been associated with depression in several diseases, their connection to PDAC in this context remains unclear. This study explored the correlation between mast cells and psychosocial stress in patients with PDAC. Prior to surgery, 40 patients with PDAC (n = 29 primary resected, n = 11 neoadjuvant treated) completed four questionnaires assessing stress and quality of life. Immunostaining was performed on the resected tumor tissue. Spearman analysis was employed to correlate mast cells with distress and neuropeptides serotonin and beta-endorphin serum and tissue levels. Patients with PDAC exhibited elevated levels of distress and worry. Lower number of mast cells within the tumor correlated with greater psychological burden. Among primary resected patients, mast cell count moderately correlated with joy and inversely with worries. Following neoadjuvant chemotherapy, strong inverse correlation was observed between anxiety, depression, and mast cell quantity. No correlation was found between mast cells and serotonin or beta-endorphin levels. In summary, mast cell presence inversely correlates with psychosocial stress, suggesting a link between immune cells and psychological well-being in pancreatic cancer. Targeting mast cells might offer therapeutic avenues for addressing cancer-induced depression and anxiety. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Alteration of airway neuronal function and density and bidirectional interaction between immune cells and sensory peripheral nerves have been proposed to trigger and perpetuate inflammation that contribute to asthma severity. To date, few studies analysed neuroplasticity and neuroinflammation in tissue of asthmatic individuals. We hypothesized that the presence of these phenomena would be a pathological feature in fatal asthma.We have quantified the expression of the pan‐neuronal marker PGP9.5 and the neuronal sensory‐derived neuropeptide calcitonin gene‐related peptide (CGRP) in the large airways of 12 individuals deceased due to an asthma attack and compared to 10 control lung samples. The proximity between nerve bundles to eosinophils, mast cells and CADM1+ cells was also quantified. We have additionally developed a hPSC‐derived sensory neuron/mast cell co‐culture model, from where mast cells were purified and differences in gene expression profile assessed.Fatal asthma patients presented a higher PGP9.5 and CGRP positive area in the airways, indicating sensory neuroplasticity. Eosinophils, mast cells and CADM1+ cells were observed in close contact or touching the airway nerve bundles, and this was found to be statistically higher in fatal asthma samples. In vitro co‐culture model showed that human mast cells adhere to sensory neurons and develop a distinct gene expression profile characterized by upregulated expression of genes related to heterophilic adhesion, activation and differentiation markers, such as CADM4, PTGS2, C‐KIT, GATA2, HDC, CPA3, ATXN1 and VCAM1.Our results support a significant role for neuroplasticity and neuroimmune interactions in fatal asthma, that could be implicated in the severity of the fatal attack. Accordingly, the presence of physical neuron and mast cell interaction leads to differential gene expression profile in the later cell type. [ABSTRACT FROM AUTHOR]

Objective: The primary objective of this review is to focus on research findings that aim to determine the immunomodulatory action of ginger's active components and the molecular mechanisms that reduce asthma. The study aims to provide an overview of the scientific literature available on ginger's efficacy in treating allergic asthma. Data Source: The mouse model of asthma has been used to investigate the actions of ginger and its active compounds on allergies and asthma. Various studies and scientific literature on ginger's health-improving qualities and its traditional use have been examined. Results: The findings indicate that ginger and its active ingredients have anti-asthmatic features and a suppressive impact on mast cell production of histamine. Animals given ginger and compounds derived from ginger demonstrate a notable reduction in allergic response, suggesting a significant role in lowering the allergic reaction. Conclusion: While ginger shows promise as a potential treatment for allergies and asthma due to its anti-inflammatory, antibacterial, antidiabetic, anticancer, and antioxidant effects, further examination, extrapolation, and confirmation of these results are necessary before utilizing ginger and its active components in human treatments. This review highlights the need for additional research and provides an overview of the current scientific literature on ginger's efficacy in treating allergic asthma. [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: Histopathologic criteria for diagnosis of cutaneous mastocytosis include 20 mast cells per high‐power field or clusters of 15 mast cells. We aimed to determine the specificity of these criteria for cutaneous mastocytosis in comparison with inflammatory disorders of mast cell activation. Methods: Twenty‐six cases of spongiotic dermatitis or urticaria were identified from 2021 to 2022. Recuts were stained with mast cell tryptase and slides were reviewed for the presence of 20 mast cells per high‐power field and for clusters of 15 mast cells. In addition, seven cases of mastocytosis were reviewed for the same criteria. Results: Twelve of 26 cases (46.1%) of spongiotic dermatitis/urticaria had at least 20 mast cells per high‐power field. Three of 26 cases (11.5%) of spongiotic dermatitis/urticaria had a cluster of 15 mast cells. Six of seven cases (85.7%) of mastocytosis had at least 20 mast cells per high‐power field; four of seven cases (57.1%) of mastocytosis had a cluster of 15 mast cells. Conclusions: In our study, the finding of 20 mast cells per high‐power field was nonspecific as a single criterion for cutaneous mastocytosis. The finding of clusters of 15 mast cells was more specific but not sensitive. [ABSTRACT FROM AUTHOR]

Background: The subcellular distribution of CD30 on mast cells and the presence of eosinophils in cutaneous mastocytosis require further investigation, especially as the cell surface expression of CD30 is critical for the therapeutic response of systemic mastocytosis to brentuximab vedotin. Objective: Investigation of 147 biopsy specimens from 143 patients with cutaneous mastocytosis for mast cell density and distribution, frequency of CD30 expression, CD30 staining patterns, and presence and distribution of eosinophils. Correlation with clinical patterns. Methods: Retrospective multicenter immunohistochemical study of CD30 expression, eosinophils and basic clinical data in cutaneous mastocytosis. Results: CD30 expression was found in all samples (cut‐off: ≥1%), whereby the staining was predominantly cytoplasmic in 99% of the samples. Additional membrane staining was detected in 62% of the samples. Surface expression of CD30 was more common in biopsy specimens with a high mast cell burden and in biopsy specimens with a higher CD30 expression rate. Eosinophils were admixed in 58% of the samples. Females and older patients showed a trend of a lower mast cell burden. Limitations: Retrospective study on formalin‐fixed and paraffin‐embedded tissue without functional analysis. Conclusion: Most cases of cutaneous mastocytosis show cell surface expression of CD30 expression and is, therefore, in principle, accessible for therapy with antibodies against CD30, provided the overall situation of the patient warrants. [ABSTRACT FROM AUTHOR]

Interleukin (IL)‐33 released from airway epithelial cells plays a vital role in shaping type 2 immune responses by binding to the ST2 receptor present in many immune cells, including mast cells (MCs). Intranasal administration of IL‐33 in mice induces type 2 lung inflammation, an increase in lung MC progenitors, and transepithelial migration of leukocytes to the bronchoalveolar space. The aim of this study was to determine the contribution of MCs in IL‐33‐induced lung pathology. Four daily intranasal administrations of IL‐33 reduced spirometry‐like lung function parameters, induced airway hyperresponsiveness, and increased leukocytes in bronchoalveolar lavage fluid (BAL) in an ST2‐dependent manner. MC‐deficient (Cpa3cre/+) mice, which lack MCs, had intact spirometry‐like lung function but slightly reduced airway hyperresponsiveness, possibly related to reduced IL‐33 or serotonin. Strikingly, Cpa3cre/+ mice exposed to IL‐33 had 50% reduction in BAL T‐cells, and CXCL1 and IL‐33 were reduced in the lung. Intranasal IL‐33 induced CXCR2 expression in T‐cells in a MC‐independent fashion. Furthermore, IL‐33‐induced lung MCs were immunopositive for CXCL1 and localized in the epithelium of wild‐type mice. These results suggest that MCs are required to sustain intact lung IL‐33 and CXCL1 levels in mice with IL‐33‐induced airway inflammation, thereby facilitating T‐cell accumulation in the bronchoalveolar space. [ABSTRACT FROM AUTHOR]

Air pollution as a result of intensified anthropogenic activity leads to the elevated cases of respiratory diseases. One of them is occupational asthma, which is described in this study by ecological aetiology. The mechanism of action of pollutants (allergens) on the mast cells - structural elements of symbiotic adaptation between humanity, environment, and the Technosphere - is systematized. Human immunity is described symbiotically and homeostatically by the expression of Gibbs energy, which is the main energetic moment of this complex unit Noosphere-BiosphereTechnosphere. The pathophysiological mechanisms of asthma with the creation of the complexes “mast+IgE” are also described by the quantitative expression of Gibbs free energy. Regarding this expression, decisions can be made for the combating of high levels of pollutants in the atmosphere as well as regarding prophylactic and therapeutic measures. [ABSTRACT FROM AUTHOR]

Effector CD4+ T (Teff) lymphocytes infiltrate sites of inflammation and orchestrate the immune response by instructing local leukocytes. Mast cells (MCs) are tissue sentinel cells strategically located near blood vessels and T cell–rich areas. MC/Teff cell interactions shape Teff cell responses, but in turn, Teff cell action on MCs is still poorly understood. Here, we analyzed the human MC/Teff cell interplay through both the application of RNA sequencing and functional assays. We showed that activated Teff cells induce a specific transcriptomic program in MCs including production of both inflammatory cytokines and chemokines, prostaglandin, and a FcεRI-dependent degranulation facilitation, thereby driving them toward an inflammatory phenotype. Moreover, Teff cells induce in MCs the capacity to interact with CD4+ T cells through a wide range of dedicated soluble and membrane ligands and to play the role of antigen-presenting cells. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease is caused by the inhalation of noxious particles such as cigarette smoke. The pathophysiological features include airway inflammation, alveolar destruction, and poorly reversible airflow obstruction. A subgroup of patients with chronic obstructive pulmonary disease has higher blood eosinophil counts, associated with an increased response to inhaled corticosteroids and increased biomarkers of pulmonary type 2 inflammation. Emerging evidence shows that patients with chronic obstructive pulmonary disease with increased pulmonary eosinophil counts have an altered airway microbiome. Higher blood eosinophil counts are also associated with increased lung function decline, implicating type 2 inflammation in progressive pathophysiology in chronic obstructive pulmonary disease. We provide a narrative review of the role of eosinophils and type 2 inflammation in the pathophysiology of chronic obstructive pulmonary disease, encompassing the lung microbiome, pharmacological targeting of type 2 pathways in chronic obstructive pulmonary disease, and the clinical use of blood eosinophil count as a chronic obstructive pulmonary disease biomarker. [ABSTRACT FROM AUTHOR]

Objectives: To date, few studies have considered the influence of psychological factors on chronic prostatitis (PRO) models. Here, we aimed to refine a murine PRO model combining chemically induced prostatitis with psychological stress. Methods: A total of 40 mice were randomly divided into four groups: normal control (NC) group, PRO group, water avoidance stress (WAS) group, and PRO + WAS group. Ten mice were assigned to each group: five for cystometrograms (CMGs) and five for von Frey testing and histological analysis. PRO was induced through a prostatic injection of 10% paraformaldehyde. The WAS mice were placed on the middle platform for 1 h per day for 10 consecutive days. Results: The results of the von Frey test demonstrated that both WAS and PRO induced bladder hyperalgesia in mice, and the WAS + PRO group showed significant pelvic pain symptoms either. The CMG results suggested that the PRO group, the WAS group, and the PRO + WAS group all exhibited bladder overactivity, presented as a shortened micturition interval and decreased threshold pressure evoking bladder contraction. The symptoms of the PRO group and the PRO + WAS group were more severe than those of the WAS group. The tissue staining results indicated that WAS itself caused only mild prostatic inflammation but could significantly aggravate chemical‐induced prostatic inflammation, as well as the total number of mast cells and proportion of activated mast cells. Conclusions: Our refined murine PRO model could manifest persistent bladder overactivity, pelvic hyperalgesia and prostatic inflammation. WAS could induce mild prostatic inflammation and aggravate primary prostatic inflammation. [ABSTRACT FROM AUTHOR]

Introduction: Because MRGPRX2 is now recognized as the mast cell receptor for basic secretagogues, there is currently a tremendous interest in whetherMRGRPX2 could play an important role in various pruritic dermatoses such as chronic spontaneous urticaria. Therefore, we sought to identify new potent and selective antagonists to pharmacologically characterize the biological role of MRGPRX2. Methods: Various relevant in vitro, ex vivo, and in vivo model systems were used to investigate the role of MRGPRX2. This included the study of freshly isolated human skin mast cells and human basophils as well as an ex vivo human skin microdialysis preparation. The additivity of MRGPRX2 and FceR1-mediated degranulation was also investigated. Human MRGPRX2 knock-in mice were generated to interrogate pharmacokinetic/pharmacodynamic relationships because both antagonists studied were shown to be human specific. Results: Two novel and structurally distinct MRGPRX2 antagonists were identified with one, Compound B, being orally active and demonstrating high potency in blocking Substance P-mediated degranulation using freshly isolated human skin mast cells with half maximal inhibitory concentration (IC50) at 0.42 nM. Compound B also potently blocked Substance P-stimulated histamine release from resident mast cells in a human skin explant setup as well as blocking itch in an established behavioral scratching model using MRGPRX2 knock-in mice. Unlike human mast cells, Substance P failed to elicit a functional response in human basophils. Conclusion: These data fully support the investigation of MRGPRX2 receptor antagonists in mast cell-driven allergic skin disorders such as chronic spontaneous urticaria. [ABSTRACT FROM AUTHOR]

Interleukin-33 (IL-33) is an alarmin released by epithelial cells in response to tissue damage. It activates resident immune sentinel cells, which then produce signals commonly associated with type 2 immune responses, particularly affecting infiltrating antigen-specific T cells. Given that mast cells (MCs) are a primary target of IL-33 and can shape T helper (Th) cell responses, we investigated the effect of IL-33 priming on the ability of MCs to influence Th cell cytokine production. To examine the Th cell/MC interaction, we developed human primary MC/memory CD4+ T-cell coculture systems involving both cognate and non-cognate interactions. Our results demonstrated that IL-33-primed MCs, whether as bystander cells cocultured with activated effector T cells or functioning as antigen-presenting cells, promoted IL-9 and increased IL-13 production in Th cells via an OX40L-dependent mechanism. This indicates that MCs sense IL-33-associated danger, prompting them to direct Th cells to produce the key type 2 effector cytokines IL-9 and IL-13. [ABSTRACT FROM AUTHOR]

Background: Esophageal cancer (EC) is a major health issue, ranking seventh in incidence and sixth in mortality worldwide. Despite advancements in multidisciplinary treatment approaches, the 5-year survival rate for EC remains low at 21%. Challenges in EC treatment arise from late-stage diagnosis, high malignancy, and poor prognosis. Understanding the tumor microenvironment is critical, as it includes various cellular and extracellular components that influence tumor behavior and treatment response. Mast cells (MCs), as tissue-resident immune cells, play dual roles in tumor dynamics. High-throughput single-cell RNA sequencing offers a powerful tool for analyzing tumor heterogeneity and immune interactions, although its application in EC is limited. Methods: In this study, we investigated the immune microenvironment of EC using single-cell RNA sequencing and established a comprehensive immune profile. We also performed analysis of upstream transcription factors and downstream pathway enrichment to further comprehensively decipher MCs in EC. Besides, we performed knockdown experiments to explore the role of epidermal growth factor receptor (EGFR) signaling pathway in MCs-tumor cell interactions, highlighting its potential as a prognostic marker. Finally, we constructed a prognostic model for EC, which provided valuable suggestions for the diagnosis and prognosis of EC. Results: Our analysis identified 11 major cell types, of which MCs were particularly present in pericarcinoma tissues. Further grouping of the 5,001 MCs identified 8 distinct subtypes, including SRSF7-highly expressed MCs, which showed strong tumor preference and potential tumor-promoting properties. Moreover, we identified the key signaling receptor EGFR and validated it by in vitro knockdown experiments, demonstrating its cancer-promoting effects. In addition, we established an independent prognostic indicator, SRSF7+ MCs risk score (SMRS), which showed a correlation between high SMRS group and poor prognosis. Conclusion: These findings illuminate the complex interactions within the tumor microenvironment of EC and suggest that targeting specific MCs subtypes, particularly via the EGFR signaling pathway, may present novel therapeutic strategies. This study establishes a comprehensive immune map of EC, offering insights for improved treatment approaches. [ABSTRACT FROM AUTHOR]

Introduction: Allergic asthma has been linked to the activation of mast cells (MCs) by the neuropeptide substance P (SP), but the mechanism underlying this neuroimmune interaction is unknown. Substance P produced from cutaneous nociceptors activates MCs via Mas-related G-protein-coupled receptor B2 (MrgprB2) to enhance type 2 immune response in experimental atopic dermatitis in mice. We recently showed that the adapter protein β-arrestin2 (β-arr2) contributes to MrgprB2-mediated MC chemotaxis. The goals of this study were to determine if MrgprB2 facilitates neuroimmune interaction in IgE (FcεRI)-mediated allergic airway inflammation (AAI) and to assess if this response is modulated by β-arr2. Methods: Wild-type (WT), MrgprB2−/− mice and mice with MC-specific deletion of β-arr2 (Cpa3Cre+/β-arr2fl/fl) were passively sensitized with anti-TNP-IgE and challenged with antigen. The generation of SP and MC recruitment in the lung were determined by immunofluorescence and toluidine blue staining, respectively. The transcripts for Tac1, MrgprB2, TNF-α, and Th2 cytokines in lung tissue were assessed by RT-PCR, and the release of selected cytokines in bronchoalveolar lavage (BAL) was determined by ELISA. Eosinophil and neutrophil recruitment in lung tissue and BAL were determined by immunofluorescence staining and flow cytometry, respectively. Goblet cell hyperplasia was determined by periodic acid–Schiff staining. Results: Following IgE sensitization and antigen challenge in WT mice, SP generation, and MC recruitment, transcripts for Tac1, MrgprB2, TNF-α, and Th2 cytokine were upregulated when compared to the control challenge. TNF-α, Th2 cytokine production, eosinophil/neutrophil recruitment, and goblet cell hyperplasia were also increased. These responses were significantly reduced in MrgprB2−/− and Cpa3Cre+/β-arr2fl/fl mice. Discussion: The data presented herein suggest that SP-mediated MrgprB2 activation contributes to AAI and goblet cell hyperplasia in mice. Furthermore, these responses are modulated by β-arr2, which promotes MC recruitment to facilitate their activation through FcεRI. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to characterize the phenotype and genotype of patients with Yao syndrome (YAOS), with focus on comparing to prior cohorts, identifying novel features, and describing treatment observations. Methods: A retrospective medical records review of patients with YAOS seen at Mayo Clinic was conducted to characterize clinical features, NOD2 genotypes, and therapeutic trials and responses. Results: Twenty-two patients diagnosed with YAOS were included. Eighteen patients (81.8%) were female and twenty (90.9%) were White. Mean age at symptom onset was 24.0 ± 14.8 years. Common clinical manifestations included fever (81.8% of patients), rash (95.5%), chronic gastrointestinal symptoms (100%), arthralgia/arthritis (95.5%), and sicca symptoms (68.2%). NOD2 genotypes as single variants included IVS8 + 158 in 14 patients (63.6%), R702W in 8 patients (36.4%), 1007fs in 4 (18.2%), and one patient had only a previously unreported rare variant. Eight patients (36.4%) had compound (two or more) NOD2 variants. Potential comorbidities of YAOS observed in this cohort included gastrointestinal dysmotility, autonomic dysfunction, and mast cell activation-like symptoms. Glucocorticoid responsiveness was observed in 15 of 20 patients exposed (75%). Eleven patients (50.0%) received IL-1 inhibitor therapy, and one patient (4.5%) received IL-6 inhibitor therapy with adequate disease control. Conclusion: Our findings substantiate the occurrence of fevers, arthralgia/ arthritis, rash, chronic gastrointestinal symptoms, and sicca-like symptoms described previously in patients with YAOS. Novel clinical features and one NOD2 variant not previously described were identified. Glucocorticoids, biologic IL-1 inhibitors, and IL-6 receptor inhibitors appeared to be effective for treatment of patients with YAOS. [ABSTRACT FROM AUTHOR]

Esophageal squamous cell carcinoma (ESCC) is a prevalent malignancy within the digestive system, characterized by high incidence and mortality rates. The biological role of REEP5 in ESCC progression remains poorly understood, despite its associations with various diseases, potentially accelerating tumor malignancy. We retrieved RNA-seq data and clinical information from 179 ESCC patients from the Gene Expression Omnibus (GEO) and 93 patients from The Cancer Genome Atlas (TCGA) databases. Bioinformatics analyses were conducted to explore the biological functions of REEP5 in ESCC, its role in the tumor microenvironment, and its prognostic value. Additionally, utilizing single-cell RNA-seq (scRNA-seq) data from 3 ESCC patients in the GEO database, we performed cluster analyses to investigate cell-specific expression differences of REEP5 between cancerous and adjacent non-cancerous tissues. Molecular biology experiments were also conducted to validate REEP5 expression disparities between tumor and non-tumor tissues. Compared to normal tissues, REEP5 was significantly enriched in ESCC tissues. High REEP5 expression was closely associated with poor prognosis in ESCC patients. Gene Ontology (GO) analysis revealed strong correlations between REEP5 and processes such as mRNA splicing and protein stabilization. Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA) indicated positive correlations between REEP5 and mRNA spliceosome assembly and disassembly. Pearson correlation analysis demonstrated positive associations between REEP5 and cancer-inhibitory immune checkpoints CTLA-4, TIM-3, and HVEM. Single-cell clustering and CIBERSORT analysis showed that REEP5 expression was closely related to T-cell infiltration in ESCC, with significant enrichment effects observed in CD8+ T-cell infiltration. REEP5 expression is closely correlated with the pathological and molecular pathology of ESCC, potentially playing a crucial role in Mast cell or T-cell-mediated immune responses in ESCC. Therefore, REEP5 holds promise as a novel therapeutic target for ESCC. [ABSTRACT FROM AUTHOR]

Lung adenocarcinoma (LUAD) is the most common lung cancer, accounting for 19.4% of all cancer deaths. Our previous study discovered that INTS7 expression was upregulated in LUAD, while the precise mechanism by which INTS7 exerts pro-cancer effects remains unknown. In our study, shRNA was used to knockdown the expression of INTS7 in A549 cells. Cancer behaviors in vitro were determined by CCK8 and transwell assays. Xenograft mice models were constructed to detect the tumorigenesis in vivo. Immunofluorescence and toluidine blue staining were used to test the immune infiltration. Bioinformatics analysis was adopted to predict the potential signaling pathways and construct INTS7-derived genomic prognostic model. Western blot was utilized to confirm the molecular pathways. In total, downregulation of INTS7 suppressed proliferation, invasion and migration of A549 cells, as well as tumor growth. Bioinformatics and western blot analysis indicated that p38MAPK pathway participated in the regulatory mechanism of INTS7. Moreover, INTS7 expression was negatively correlated with infiltration of memory B cells and mast cells, while positively correlated with infiltration of macrophages M2. A nomogram, including INTS7-derived risk score, was used to estimate individual's survival probability. Generally, our findings provided comprehensive understanding of the molecular mechanisms about INTS7, and targeting INTS7 may represent a potential therapy for LUAD. [ABSTRACT FROM AUTHOR]

Heterogeneous behavior of each cell type and their cross-talks in tumor immune microenvironment (TIME) refers to tumor immunological heterogeneity that emerges during tumor progression and represents formidable challenges for effective anti-tumor immune response and promotes drug resistance. To comprehensively elucidate the heterogeneous behavior of individual cell types and their interactions across different stages of tumor development at system level, a computational framework was devised that integrates cell specific data from single-cell RNASeq into networks illustrating interactions among signaling and metabolic response genes within and between cells in TIME. This study identified stage specific novel markers which remodel the cross-talks, thereby facilitating immune stimulation. Particularly, multicellular knockout of metabolic gene APOE (Apolipoprotein E in mast cell, myeloid cell and fibroblast) combined with signaling gene CAV1 (Caveolin1 in endothelial and epithelial cells) resulted in the activation of T-cell mediated signaling pathways. Additionally, this knockout also initiated intervention of cytotoxic gene regulations during tumor immune cell interactions at the early stage of Lung Adenocarcinoma (LUAD). Furthermore, a unique interaction motif from multiple cells emerged significant in regulating the overall immune response at the advanced stage of LUAD. Most significantly, FCER1G (Fc Fragment of IgE Receptor Ig) was identified as the common regulator in activating the anti-tumor immune response at both stages. Predicted markers exhibited significant association with patient overall survival in patient specific dataset. This study uncovers the significance of signaling and metabolic interplay within TIME and discovers important targets to enhance anti-tumor immune response at each stage of tumor development. [ABSTRACT FROM AUTHOR]

Immunoglobulin E (IgE)‐mediated food allergies are reported to affect around 3.5% of children and 2.4% of adults, with symptoms varying in range and severity. While being the gold standard for diagnosis, oral food challenges are burdensome, and diagnostic tools based on specific IgE can be flawed. Furthering our understanding of the mechanisms behind food allergy onset, severity and persistence could help reveal immune profiles associated with the disease, to ultimately aid in diagnosis. Alterations to cytokine levels and immune cell ratios have been identified, though further research is needed to fully capture the heterogenous nature of food allergy. Moreover, the existence of such immune alterations also raises the question of potential wider systemic effects. For example, recent research has emphasised the existence and impact of neuro‐immune interactions and implicated behavioural and neurological changes associated with food allergy. This review will provide an overview of such food allergy‐driven neuro‐immune interactions, with the aim of emphasising the importance of furthering our understanding of the immune mechanisms underlying IgE‐mediated food allergy. [ABSTRACT FROM AUTHOR]

Background: Innovative treatments are being examined to develop more effective and innocuous protective medications for allergic conditions. In recent times, helminth-based immunotherapy is gaining attention as a potential therapeutic approach that could establish a pathway for controlling anaphylaxis. To the extent of our knowledge, there are no previous studies that examine the protective effect of both Schistosoma mansoni (S. mansoni) and its soluble egg antigen (SEA) together against anaphylaxis. Therefore, the purpose of the current study was to examine and compare the impact of SEA immunization and/or S. mansoni infection on Ovalbumin (OVA)-induced systemic anaphylaxes in mice model. Results: The outcome results revealed that S. mansoni infection and SEA immunization were able to improve body weight, reduce the mortality rate, increase plasma IgE and IgG4 levels and decrease histamine levels in broncho-alveolar lavage fluid (BALF). Additionally, they elevated interleukin-(IL)-4, IL-10, interferon-gamma (IFN-γ) and transforming growth factor-beta (ΤGF-β) levels in BALF. They also restored the stabilization of peritoneal mast cells (MCs) membrane in inverted light microscopy results accompanied by amelioration of the lung and liver histology. Conclusions: The present study provided indication for the prophylactic effects of S. mansoni infection and SEA immunization against OVA-induced systemic anaphylaxes in mice model. Also, it focuses on the possible therapeutic mechanisms of helminth-derived products administration that might be related to upregulation of immune regulatory mechanisms. As a result, S. mansoni-derived products may be used as preventative supplemented treatments to inhibit the development of anaphylaxis which provides us with a new vision for developing pioneering therapy. [ABSTRACT FROM AUTHOR]

Objective: Diabetes mellitus (DM) is an important risk factor for the development of osteoarthritis (OA), increasing OA progression and OA pain. To gain insight into the underlying mechanisms of how DM exacerbates OA processes and OA pain, this study analyzed histological differences of synovial tissues from non-DM and DM patients with OA and correlated these differences with knee pain severity. Materials and methods: Synovial tissue was obtained from12 non-DM and 10 DM patients with advanced knee OA who underwent total knee arthroplasty. Synovial inflammation was assessed using the Synovitis score developed by Krenn. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to assess knee pain intensity and disability in OA patients. The number of mast cells, macrophages, nerve fibers, capillaries, larger vessels and erythrocyte extravasation were analyzed microscopically in histological and immunostained synovial sections fromnon-DM and DM patients. Association analyses were performed to determine associations between OA knee pain and synovial changes affected by DM. Results: Synovial tissue from OA patients with DM had a higher synovitis score, more erythrocyte extravasation, and contained higher numbers of mast cells and macrophages compared to non-DM patients. The number of capillaries and vessels in the lining/sublining layer of the synovial tissue was reduced in DM patients. OA patients with DM had more severe knee pain compared to non-DM patients. The KOOS pain score was associated with the synovitis score, the number of tissue macrophages, and the number of mast cells in the synovial tissue (adjusted for age, sex, and BMI). In addition, the erythrocyte extravasation score was associated with the KOOS pain score and with the synovitis score. Conclusion: The study suggests that increased OA progression and pain severity in patients with DM result from more pronounced synovitis and synovial vascular leakage and increased infiltration of macrophages and mast cells. [ABSTRACT FROM AUTHOR]

The specificity of cytokine and immunoreceptor signaling frequently depends upon receptor recruitment of select adaptor proteins and specifically engaged effectors. This review focuses on the orthologous adaptor proteins, HGAL and C1ORF150, and aims to provide insight into their respective modulation of lymphoid and myeloid cell signaling, formation, and function. HGAL acts predominantly within germinal center B cells as an important BCR signal transducer. Effects on BCR signalosome assembly involve HGAL's localization to the plasma membrane via its lipidation, initial interactions with SYK, the pYphosphorylation of HGAL including its recruitment of GRB2, and HGAL engagement of PDZ-RhoGEF and RhoA signaling. At ligated BCRs, this includes HGAL(-GRB2) stimulation of SYK kinase, attenuation of calcium flux-dependent and NF-kB expression, promotion of cSMAC formation, and cytoskeletal remodeling associated with HGAL-attenuated cell migration. HGAL and partnered effectors also impact on DLBCL pathogenesis, and studies are summarized on HGAL's actions (using DLBCL and Burkitt lymphoma B cells) including cell migration effects, HGAL modulation of cytoskeletal components, and insightful HGAL transgenic mouse and xenograft models. For C1ORF150, its HGAL-homologous subdomains are considered, together with studies that demonstrate C1OR150's FceRI- and KIT-mediated expression and phosphorylation in primary human mast cells. Intriguingly, recent GWAS studies have identified a C1ORF150 in-frame splice variant that is strongly associated with urticaria. Candidate mechanisms via which the encoded "C1ORF150-Dexon2" isoform affects mast cell degranulation are considered, including FceR1 and/or KIT receptor connections, and candidate "myristoylation switch" mechanisms. [ABSTRACT FROM AUTHOR]

Background: Mast cells (MCs) are multifaceted immune cells that are capable of recognizing and responding to various stimuli by releasing an array of cytokines. We aimed to use human cord blood-derived mast cells (hCBMCs) as a model to evaluate different conditions under which chemokines and growth factors are expressed and secreted as mediators upon stimulation with the alarmin interleukin-33 (IL-33). Methods: hCBMCs were stimulated with 10 ng/mL or 20 ng/mL of recombinant human IL-33 (rhIL-33) for 6 h (acute) or 24 h (chronic). The mRNA expression of chemokines and growth factors was analyzed using microarrays, and the mediators released in the supernatant were evaluated using a multiplex assay. Results: The mRNA expression levels of C-C chemokine ligands (CCL) CCL1, CCL5, granulocyte macrophage colony-stimulating factor (GM-CSF), and macrophage inflammatory protein (MIP)-4/CCL18 were upregulated under all conditions. In contrast, C-X-C motif chemokine ligand (CXCL) CXCL8 and CCL24 levels increased only under acute (6 h) and prolonged (24 h) conditions, respectively. Moreover, high levels of CXCL8, MIP-1α, and MIP-1β were secreted during acute inflammation, whereas the release of GM-CSF and CXCL9 proteins increased under all four conditions. Conclusions: This study highlights the sentinel role of MCs in mounting a specific immune response against a pathogenic-like stimulus in a timely and dose-dependent manner and is relevant for improving inflammatory treatment options. [ABSTRACT FROM AUTHOR]

The article "Thoughts on mastocytosis in COVID-19: an author's response" published in Histopathology discusses the potential role of mast cells in thrombosis and pulmonary fibrosis in COVID-19 patients. While the increase in mast cells may not establish a causal relationship, it could play a significant role in these conditions. The authors suggest that further studies are needed to determine the extent to which an increase in mast cells is a normal physiological response to viral infection in the lungs. Additionally, the influence of obesity on tryptase levels in COVID-19 patients is considered, although limited control samples were available for comparison. [Extracted from the article]

The article "Redefining tryptase norms in the pediatric population reveals sex-based differences: Clinical implications" discusses the measurement of serum basal tryptase (sBT) levels in children to diagnose mast cell activation disorders. The study included 398 children, with a median sBT level of 3.2 ng/mL, and found that sBT levels were significantly higher in infants under 1 year old. There were sex-based differences in sBT levels, with males having higher levels than females, particularly in the oldest age group. The study suggests that the 8.0 ng/mL threshold used in adults may also be suitable for screening boys for hereditary alpha-tryptasemia, while a lower threshold of 7.0 ng/mL may be more appropriate for girls aged 5 and above. [Extracted from the article]

ABSTRACT Nodal metastasis is a negative prognostic factor in dogs with mast cell tumours (MCTs), thus early detection enables more informed decision‐making and provides valuable prognostic information. The aim of this study is to assess the concordance between histopathologic findings of LNs and cytology and flow cytometry (FC), respectively, and to evaluate the ability of FC to differentiate between metastatic (HN2–HN3) and non‐metastatic (HN0–HN1) LNs. Overall, 117 LNs from 64 dogs with first occurring MCTs were submitted for cytology, histology and FC. LNs were cytologically and histologically classified according to Krick and Weishaar systems, respectively. Using FC, mast cells (MCs) were identified as IgE+ CD117+ CD5− CD21− cells and quantified as a percentage. When compared with histologic classification, cytology showed an accuracy of 88.2% in distinguishing between metastatic and non‐metastatic LNs but did not detect 25.3% of metastatic cases. FC revealed an increase in the median percentages of MCs across histologic classes, progressing from HN0 to HN3. ROC curves pinpointed 0.3% as the optimal cut‐off for distinguishing between metastatic and non‐metastatic LNs, with an accuracy of 84.3%. A 1.1% cut‐off proved valuable in identifying HN3 LNs. The combined interpretation of cytology and FC increased accuracy to 92.2%. An algorithm for guiding the combined interpretation of cytology and FC is suggested based on these findings. In conclusion, FC proves beneficial in enhancing the early detection of metastatic LNs, particularly when utilised alongside cytology. Histopathology remains essential for confirmation, enabling the discrimination of HN classes or, in doubtful cases, for the detection or exclusion of nodal metastases. [ABSTRACT FROM AUTHOR]

Skin mast cells (MCs) mediate acute allergic reactions in the cutaneous environment and contribute to chronic dermatoses, including urticaria, and atopic or contact dermatitis. The cAMP response element binding protein (CREB), an evolutionarily well conserved transcription factor (TF) with over 4,000 binding sites in the genome, was recently found to form a feedforward loop with KIT, maintaining MC survival. The most selective MC function is degranulation with its acute release of prestored mediators. Herein, we asked whether CREB contributes to the expression and function of the degranulation-competent receptors FcεRI and MRGPRX2. Interference with CREB by pharmacological inhibition (CREBi, 666-15) or RNA interference only slightly affected the expression of these receptors, while KIT was strongly attenuated. Interestingly, MRGPRX2 surface expression moderately increased following CREB-knockdown, whereas MRGPRX2-dependent exocytosis simultaneously decreased. FcεRI expression and function were regulated consistently, although the effect was stronger at the functional level. Preformed MC mediators (tryptase, histamine, β-hexosaminidase) remained comparable following CREB attenuation, suggesting that granule synthesis did not rely on CREB function. Collectively, in contrast to KIT, FcεRI and MRGPRX2 moderately depend on unperturbed CREB function. Nevertheless, CREB is required to maintain MC releasability irrespective of stimulus, insinuating that CREB may operate by safeguarding the degranulation machinery. To our knowledge, CREB is the first factor identified to regulate MRGPRX2 expression and function in opposite direction. Overall, the ancient TF is an indispensable component of skin MCs, orchestrating not only survival and proliferation but also their secretory competence. [ABSTRACT FROM AUTHOR]

Simple Summary: Siglec-8 has been identified as a promising target to treat eosinophilic and mast cell disorders. However, there are currently few Siglec-8 antibodies available, and therapeutic efforts have so far primarily focused on unconjugated antibodies, which may be insufficiently effective in many patients. To address these limitations, we raised a diverse panel of fully human Siglec-8 antibodies as the basis for novel therapeutics. They were all efficiently internalized, suggesting their potential to deliver cytotoxic payloads. T cell-engaging bispecific antibodies and chimeric antigen receptor (CAR)-modified natural killer (NK) cells built from these Siglec-8 antibodies were highly potent against Siglec-8-positive cells even in cases of very low target antigen abundance. Importantly, mechanistic studies with target cells expressing either full-length Siglec-8 or an artificial smaller Siglec-8 variant demonstrated that T cell-engaging bispecific antibodies and CAR-modified NK cells were substantially more effective if they bound Siglec-8 closer to the cell membrane, indicating targeting membrane-proximal epitopes enhances effector functions of Siglec-8 antibody-based therapeutics. Indeed, tool therapeutics that bind one of the membrane-proximal C2-set domains of Siglec-8 were very effective against Siglec-8-positive target cells. Together, these data demonstrate Siglec-8-directed immunotherapies can be highly potent, supporting their further development for eosinophilic and mast cell disorders. Background/Objective: Current treatments for eosinophilic and mast cell disorders are often ineffective. One promising target to improve outcomes is sialic acid-binding immunoglobulin-like lectin-8 (Siglec-8). As limitations, there are few Siglec-8 monoclonal antibodies (mAbs) available to date, and Siglec-8-directed treatments have so far primarily focused on unconjugated mAbs, which may be inadequate, especially against mast cells. Methods: Here, we used transgenic mice to raise a diverse panel of fully human mAbs that either recognize the V-set domain, membrane-distal C2-set domain, or membrane-proximal C2-set domain of full-length Siglec-8 as a basis for novel therapeutics. Results: All mAbs were efficiently internalized into Siglec-8-expressing cells, suggesting their potential to deliver cytotoxic payloads. Tool T cell-engaging bispecific antibodies (BiAbs) and chimeric antigen receptor (CAR)-modified natural killer (NK) cells using single-chain variable fragments from Siglec-8 mAbs showed highly potent cytolytic activity against Siglec-8-positive cells even in cases of very low target antigen abundance, whereas they elicited no cytolytic activity against Siglec-8-negative target cells. Siglec-8V-set-directed T cell-engaging BiAbs and Siglec-8V-set-directed CAR-modified NK cells induced substantially greater cytotoxicity against cells expressing an artificial smaller Siglec-8 variant containing only the V-set domain than cells expressing full-length Siglec-8, consistent with the notion that targeting membrane-proximal epitopes enhances effector functions of Siglec-8 antibody-based therapeutics. Indeed, unconjugated Siglec-8C2-set mAbs, Siglec-8C2-set-directed T cell-engaging BiAbs, and Siglec-8C2-set-directed CAR-modified NK cells showed high antigen-specific cytolytic activity against Siglec-8-positive human cell lines and primary patient eosinophils. Conclusions: Together, these data demonstrate Siglec-8-directed immunotherapies can be highly potent, supporting their further development for eosinophilic and mast cell disorders. [ABSTRACT FROM AUTHOR]

Malabsorption of NaCl is the primary cause of diarrhea in inflammatory bowel disease (IBD). Coupled NaCl absorption occurs via the dual operation of Na:H and Cl:HCO3 exchange in the brush border membrane (BBM) of villus cells. Cl:HCO3 exchange is mediated by BBM transporters DRA (downregulated in adenoma) and PAT1 (putative anion transporter 1) in the mammalian small intestine. DRA/PAT1-mediated Cl:HCO3 exchange was significantly downregulated in the BBM of villus cells in a rabbit model of chronic ileitis, while Na:H exchange was unaffected. The inhibition of Cl:HCO3 exchange was restored in the rabbits when treated with a broad-spectrum immunomodulator, i.e. a glucocorticoid, indicating that the downregulation of DRA/PAT1 is likely to be immune-mediated during chronic enteritis. Mucosal mast cells are one type of key immune cells that are known to proliferate and release immune inflammatory mediators, thus playing a significant role in the pathogenesis of IBD. However, how mast cells may regulate DRA- and PAT1-mediated Cl:HCO3 exchange in a rabbit model of chronic ileitis is unknown. In this study, treatment of rabbits with chronic intestinal inflammation with the mast cell stabilizer ketotifen did not affect the mucosal architecture of the inflamed intestine. However, ketotifen treatment reversed the inhibition of Cl:HCO3 activity in the BBM of villus cells. This restoration of Cl:HCO3 activity to normal levels by ketotifen was found to be secondary to restoring the affinity of the exchangers for its substrate chloride. This observation was consistent with molecular studies, where the mRNA and BBM protein expressions of DRA and PAT1 remained unaffected in the villus cells under all experimental conditions. Thus, this study indicates that mast cells mediated the inhibition of coupled NaCl absorption by inhibiting Cl:HCO3 exchange in a rabbit model of chronic enteritis. [ABSTRACT FROM AUTHOR]

Molecular hydrogen (H2) has antioxidant, anti-inflammatory, and anti-fibrotic effects. In a rat model simulating pulmonary fibrotic changes induced by monocrotaline-induced pulmonary hypertension (MPH), we had previously explored the impact of inhaled H2 on lung inflammation and blood pressure. In this study, we further focused the biological effects of H2 on mast cells (MCs) and the parameters of the fibrotic phenotype of the local tissue microenvironment. MPH resulted in a significantly increased number of MCs in both the pneumatic and respiratory parts of the lungs, an increased number of tryptase-positive MCs with increased expression of TGF-β, activated interaction with immunocompetent cells (macrophages and plasma cells) and fibroblasts, and increased MC colocalization with a fibrous component of the extracellular matrix of connective tissue. The alteration in the properties of the MC population occurred together with intensified collagen fibrillogenesis and an increase in the integral volume of collagen and elastic fibers of the extracellular matrix of the pulmonary connective tissue. The exposure of H2 together with monocrotaline (MCT), despite individual differences between animals, tended to decrease the intrapulmonary MC population and the severity of the fibrotic phenotype of the local tissue microenvironment compared to changes in animals exposed to the MCT effect alone. In addition, the activity of collagen fibrillogenesis associated with MCs and the expression of TGF-β and tryptase in MCs decreased, accompanied by a reduction in the absolute and relative content of reticular and elastic fibers in the lung stroma. Thus, with MCT exposure, inhaled H2 has antifibrotic effects involving MCs in the lungs of rats. This reveals the unknown development mechanisms of the biological effects of H2 on the remodeling features of the extracellular matrix under inflammatory background conditions of the tissue microenvironment. [ABSTRACT FROM AUTHOR]

More than 90% of patients affected by mastocytosis are characterized by a somatic point mutation of KIT, which induces ligand-independent activation of the receptor and downstream signal triggering, ultimately leading to mast cell accumulation and survival. The most frequent mutation is KIT p.D816V, but other rarer mutations can also be found. These mutations often have a very low variant allele frequency (VAF), well below the sensitivity of common next-generation sequencing (NGS) methods used in routine diagnostic panels. Highly sensitive methods are developing for detecting mutations. This review summarizes the current indications on the recommended methods and on how to manage and interpret molecular data for the diagnosis and follow-up of patients with mastocytosis. [ABSTRACT FROM AUTHOR]