Eosinophilic Response Research Articles

Chrysene contribution to bronchial asthma: Activation of TRPA1 disrupts bronchial epithelial barrier via ERK pathway

BackgroundElevated polycyclic aromatic hydrocarbon (PAH) levels are associated with exacerbation of asthma. Chrysene is one of the most prevalent unsubstituted PAHs in the environment. Transient receptor potential ankyrin 1 (TRPA1) can be used as a chemoreceptor to detect inhaled stimuli and plays an important role in the occurrence and deterioration of asthma. Whether exposure to a high concentration of chrysene in the environment can activate TRPA1 and contribute to the development of asthma, potentially through the dysfunction of the bronchial epithelial barrier, remains unclear. MethodsA cell-based assay was performed to verify the downregulation of the expression of E-cadherin and tight junction (TJ) proteins by chrysene in bronchial epithelial cells to explore the role of chrysene-mediated TRPA1 activation in the regulation of TJ protein expression through the extracellular signal-regulated protein kinase (ERK) pathway. Animal tests were conducted to determine whether chrysene could enhance airway hyperresponsiveness (AHR) induced by house dust mites (HDMs) and disrupt barrier function, thereby contributing to asthma. ResultsThe cell-based assay revealed that chrysene could disrupt the function of the bronchial epithelial barrier and decrease the expression levels of E-cadherin, zonula occludens-1 (ZO-1), occludin, and claudin-5 through the ERK pathway. Chrysene induced airway epithelial barrier dysfunction primarily through TRPA1 instead of transient receptor potential vanilloid 1. TRPA1 knockdown was able to attenuate chrysene-induced downregulation of TJ protein expression and downregulate ERK activation (p-ERK). Compared with exposure to HDM alone, coexposure to chrysene and HDM resulted in an increased incidence of AHR, disruption of barrier function, and eosinophilic inflammatory responses in a mouse model of asthma. Coexposure to chrysene and HDM increased TRPA1 expression. The animal test verified that the TRPA1 inhibitor HC030031 could suppress chrysene and HDM-induced asthma in mice. ConclusionsOur findings showed that chrysene contributed to the breakdown of the function of the bronchial epithelial barrier through the TRPA1–ERK axis and therefore acted as an adjuvant to contribute to asthma.

Determining the Role of EPX Enzyme and The Prevalenyce of Fasciola Hepatica in Patients with Cholelithiasis

Background : Fascioliasis is a parasitic infection typically caused by Fasciola Hepatica , EPX is one of toxic granules that released by eosinophils in response to infection by this parasite. Aim of study: To determining the epidemiological prevalence of Liver fluke (Fasciola Hepatica ) in patients suffering from gallstones and assessment of serum concentrations of eosinophil marker in these patients and control groups by ELISA. technique. Methodology: Case control study design, included 140 participants, 70 of them included as cases (suffered from Cholelithiasis), and 70 of them included as controls. History of the study was from beginning of October 2023 to end of January 2024, all participants were attending to Al-Sader Medical City/Digestive System Unit, Al-Hakeem Hospital and Al-Haidarya Hospital. Two samples (stool and 5 ml serum) were taken from each participant for microscopic detection of F. hepatica and for measure immune parameter EPX by ELISA, respectively. Results: It was found that there is a statistically significant difference between patients with liver fluke (Fasciola Hepatica ), where the percentage of patients with liver fluke (Fasciola Hepatica ) was 10%. Only 90% of participants suffering from gallstones were negative for this parasite. There was statistically significant (p-value= 0.0001), increase in mean concentration of the parameters (EPX,) between the two groups of patients (29.1±14.04 ng/ml,) and the control (16.76±6.16 ng/ml,) respectively. And there was a known increase in the mean concentration of immune parameter in the serum of patients infected with the parasite (EPX: 56.88±6.78 ng/ml,) compared to their concentration in patients not infected with the parasite. Conclusions: Only 10% of 90% of Cholelithiasis patients in the immediate study were diagnosed positive for F. hepatica parasite. There was increased in study parameter (EPX,) significantly in group of cholelithiasis patients other than control group.

Analysis of key indicators of chronic stress in cats and dogs

Stress is an integral part of the life of every organism. This issue has become especially important now, during wartime, when stress affects both humans and animals. Military events have led to unprecedented changes in the lives of both humans and animals, affecting their daily routines, social interactions, and stress levels. The study was conducted on 12 dogs and 14 cats. The effects of stressors on cortisol, glucose, total leukocytes, and eosinophils levels were shown. The study’s results show that during chronic stress, the studied animals showed an increase in cortisol and glucose levels, indicating increased stress in these animals in response to changes in their daily lives. Total leukocyte counts in dogs and cats were also higher than reference levels, indicating an immediate activation of the immune system in response to stressors. The differential response of eosinophils in animals underscores the complexity of the immune system’s response to stress. Dogs, as social animals, may experience more pronounced immune modulation in response to stressors, potentially making them more sensitive to fluctuations in immune cell numbers. The study revealed important behavioral changes in dogs and cats. Behavioral manifestations are the most visible indicators of an animal’s emotional well-being. Changes in behavior, including anxiety, hiding, vocalization, and altered social interactions, may reflect the emotional and psychological effects of stress. Our findings underscore the importance of considering individualized strategies for managing animal welfare in emergencies

Eosinophils respond to, but are not essential for control of an acute Salmonella enterica serovar Typhimurium infection in mice.

Eosinophils are a highly abundant cell type in the gastrointestinal tract during homeostatic conditions, where they have recently been reported to take on an activated phenotype following colonization by the bacterial microbiota. To date, there have been few studies investigating whether eosinophils respond to infection with enteric bacterial pathogens and/or investigating the requirements for eosinophils for effective bacterial pathogen control. In this study, we investigated the response of eosinophils to an acute enteric infection of mice with the bacterial pathogen Salmonella enterica serovar Typhimurium. We also assessed whether eosinophil deficiency impacted Salmonella burdens in the intestinal tract or impacted the systemic dissemination of Salmonella following an oral infection of littermate wild-type BALB/cJ and eosinophil-deficient ΔdblGATA BALB/cJ mice. We found comparable Salmonella burdens in the intestinal tract of wild-type and eosinophil-deficient mice and no significant differences in the levels of Salmonella disseminating to systemic organs within 3 days of infection. Despite our evidence suggesting that eosinophils are not an essential cell type for controlling bacterial burdens in this acute infection setting, we found higher levels of eosinophils in gut-draining lymph nodes following infection, indicating that eosinophils do respond to Salmonella infection. Our data contribute to the growing evidence that eosinophils are responsive to bacterial stimuli, yet the influence of and requirements for eosinophils during bacterial infection appear to be highly context-dependent.

Der Nachweis beruflich verursachter Allergien ist ein komplexes Unterfangen: ein Fallbeispiel

The detection of occupational allergies is a complex undertaking: A case study According to the recommendations for the diagnosis of occupational asthma, suspected cases require a confirmed asthma diagnosis, work-associated symptoms, evidence of sensitization to an occupational allergen and a close relationship between the occupation and the symptoms. In addition to a detailed medical history, several examinations and tests and a differentiated consideration of them are required in order to arrive at a final expert assessment. We report the case of a 58-year-old butcher who had been complaining of shortness of breath and coughing at his workplace in a slaughterhouse for 5 years. It was only after extensive investigations and a detailed medical history that a powdered kebab spice used in an adjacent room was suspected as the potential allergen. Diagnostic tests showed that the patient was sensitized to the spice. While the specific inhalation challenge (SIC) with kebab spice did not elicit an asthmatic reaction, a non-specific bronchial hyperreactivity in the insured person was observed. On the day after the SIC, the bronchial hyperreactivity was increased by a factor of three and there were further indications of eosinophilic or allergic reaction. In summary, the individual diagnostic components led to the assessment of this case as allergic occupational asthma. This case illustrates that an assessment of the individual diagnostic components in the diagnosis of occupational asthma is quite complex and not without pitfalls. Keywords: occupational asthma – diagnosis – sensitization – bronchial hyperreactivity

Salience network resting state functional connectivity during airway inflammation in asthma: A feature of mental health resilience?

BackgroundInflammation is an established contributor to the pathophysiology of depression and the prevalence of depression in those with chronic inflammatory disease is two- to four-fold higher than the general population. Yet little is known about the neurobiological changes that confer depression or resilience to depression, that occur when episodes of heightened inflammation are frequent or span many years. MethodsWe used an innovative combination of longitudinal resting state functional magnetic resonance imaging coupled to segmental bronchial provocation with allergen (SBP-Ag) to assess changes in resting state functional connectivity (rsFC) of the salience network (SN) caused by an acute inflammatory exacerbation in twenty-six adults (15 female) with asthma and varying levels of depressive symptoms. Eosinophils measured in bronchoalveolar lavage fluid and blood provided an index of allergic inflammation and the Beck Depression Inventory provided an index of depressive symptoms. ResultsWe found that in those with the highest symptoms of depression at baseline, SN rsFC declined most from pre- to post-SBP-Ag in the context of a robust eosinophilic response to challenge, but in those with low depressive symptoms SN rsFC was maintained or increased, even in those with the most pronounced SBP-Ag response. ConclusionsThus, the maintenance of SN rsFC during inflammation may be a biomarker of resilience to depression, perhaps via more effective orchestration of large-scale brain network dynamics by the SN. These findings advance our understanding of the functional role of the SN during inflammation and inform treatment recommendations for those with comorbid inflammatory disease and depression.

Blistering Disorders of the Foot.

Multiple pathophysiologic and biomolecular processes lead to bullae, including disruption of adhesion molecules, accumulation of cell injury, and traumatic injury. Blistering disorders of the foot can cause symptoms such as pruritus, pain, and drainage and significantly impact quality of life. Microbiologic and histopathologic examination of tissue specimens should be considered for concerns regarding atypical etiology.This retrospective case series describes patients seen in a community hospital outpatient wound center in southeastern Wisconsin between January 2021 and June 2023 for atypical blistering disorders of the foot. The cases herein describe the history, clinical presentation, and treatment of three atypical blistering disorders of the foot. An 86-year-old man presented complaining of intensely pruritic blistering lesions to both feet. Histopathologic findings indicated eosinophilic infiltrate, and the patient was treated for an eosinophilic drug reaction. A 65-year-old man presented complaining of multiple painful blisters to the plantar aspect of both feet. Histopathologic examination of unroofed blister indicated bullous tinea. Finally, a 44-year-old man with long-standing type 1 diabetes presented complaining of a several-week history of a single blister to his anterior right foot of unknown etiology. The patient was diagnosed with bullosis diabeticorum.Blistering disorders of the foot are diagnostic challenges; diagnostic clarity is assisted by thorough history, clinical presentation, treatment response, microbial analysis, and histopathologic findings.

Children with eosinophilic esophagitis non-responsive to combination therapy have distinct esophageal transcriptomic and microbiome profile.

A combination of proton-pump inhibitors (PPI) and topical steroids (TS) is used to treat children with eosinophilic esophagitis (EoE). However, a subset of children do not respond to this combination therapy. We aimed to identify the esophageal transcriptional, cell composition, and microbial differences between the non-responders (EoE-PPI-TSnr; n = 7) and responders (EoE-PPI-TSr; n = 7) to the combination therapy for EoE and controls (n = 9) using metatranscriptomics. Differential gene expression analysis was used to identify transcriptional differences, validated using the EoE diagnostic panel (EDP). Deconvolution analysis was performed to identify differences in their cell type composition. Microbiome analysis was conducted from esophageal biopsies RNAseq data, and microbial abundance was correlated with esophageal gene expression. In all, 3164 upregulated and 3154 downregulated genes distinguished EoE-PPI-TSnr from EoE-PPI-TSr. Eosinophilic inflammatory response, cytokine signaling, and collagen formation pathways were significantly upregulated in EoE-PPI-TSnr. There was a 56% overlap in dysregulated genes between EoE-PPI-TSnr and EDP, with a perfect agreement in the directionality of modulation. Eosinophils, dendritic cells (DCs), immature DCs, megakaryocytic-erythroid progenitors, and T helper type 1 cells were significantly higher in EoE-PPI-TSnr. There was no significant difference in microbiome diversity. The relative abundance of Fusobacterium sp. and Acinetobacter sp. notably differed in EoE-PPI-TSnr and correlated with the key pathways. Our results provide critical insights into the molecular, cellular, and microbial factors associated with the lack of response to PPI and TS combination therapy in children with EoE. This study advances our understanding of the pathobiology of EoE while guiding personalized treatment strategies.

Laccase/caffeic acid-catalyzed crosslinking coupled with galactomannan alters the conformational structure of ovalbumin and alleviates Th2-mediated allergic asthma

Ovalbumin (OVA) is the major allergenic protein that can induce T helper 2 (Th2)-allergic reactions, for which current treatment options are inadequate. In this study, we developed a polymerized hypoallergenic OVA product via laccase/caffeic acid (Lac/CA)-catalyzed crosslinking in conjunction with galactomannan (Man). The formation of high molecular weight crosslinked polymers and the IgG-binding were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. The study indicated that Lac/CA-catalyzed crosslinking plus Man conjugation substantially altered secondary and tertiary structures of OVA along with the variation in surface hydrophobicity. Gastrointestinal digestion stability assay indicated that crosslinked OVA exhibited less resistance in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Mouse model study indicated that Lac-Man/OVA ameliorated eosinophilic airway inflammatory response and efficiently downregulated the expression of Th2-related cytokines (interleukin (IL)-4, IL-5, and IL-13), and upregulated IFN-γ and IL-10 expression. Stimulation of bone marrow-derived dendritic cells with Lac-Man/OVA suppressed the expression of phenotypic maturation markers (CD80 and CD86) and MHC class II molecules, and suppressed the expression levels of proinflammatory cytokines. The knowledge obtained in the present study offers an effective way to acquire a hypoallergenic OVA product that can have a therapeutic effect in alleviating OVA-induced allergic asthma.

Exploring the Activation Mechanism of the GPR183 Receptor.

The G protein-coupled receptors (GPCRs) play a pivotal role in numerous biological processes as crucial cell membrane receptors. However, the dynamic mechanisms underlying the activation of GPR183, a specific GPCR, remain largely elusive. To address this, we employed computational simulation techniques to elucidate the activation process and key events associated with GPR183, including conformational changes from inactive to active state, binding interactions with the Gi protein complex, and GDP release. Our findings demonstrate that the association between GPR183 and the Gi protein involves the formation of receptor-specific conformations, the gradual proximity of the Gi protein to the binding pocket, and fine adjustments of the protein conformation, ultimately leading to a stable GPR183-Gi complex characterized by a high energy barrier. The presence of Gi protein partially promotes GPR183 activation, which is consistent with the observation of GPCR constitutive activity test experiments, thus illustrating the reliability of our calculations. Moreover, our study suggests the existence of a stable partially activated state preceding complete activation, providing novel avenues for future investigations. In addition, the relevance of GPR183 for various diseases, such as colitis, the response of eosinophils to Mycobacterium tuberculosis infection, antiviral properties, and pulmonary inflammation, has been emphasized, underscoring its therapeutic potential. Consequently, understanding the activation process of GPR183 through molecular dynamic simulations offers valuable kinetic insights that can aid in the development of targeted therapies.

Helminth infection induces a distinct subset of CD101hi lung tissue-infiltrating eosinophils that are differentially regulated by type 2 cytokines.

Eosinophils play divergent roles in health and disease, contributing to both immunoregulatory and proinflammatory responses. Helminth infection is strongly associated with eosinophilia and the induction of the type 2 cytokines interleukin (IL)-5, IL-4 and IL-13. This study aimed to elucidate the heterogeneity of pulmonary eosinophils in response to helminth infection and the roles of IL-5, IL-4 and IL-13 in driving pulmonary eosinophil responses. Using the murine helminth model Nippostrongylus brasiliensis (Nb), we characterize a subtype of eosinophils, defined by high expression of CD101, that is induced in the lungs of Nb-infected mice and are phenotypically distinct from lung eosinophils that express low levels of CD101. Strikingly, we show that the two eosinophil subtypes have distinct anatomical localization within the lung: CD101low eosinophils are predominantly localized in the lung vasculature, whereas Nb-induced CD101hi eosinophils are predominantly localized in the extravascular lung niche. We show that CD101hi eosinophils are also induced across other models of pulmonary infection and inflammation, including a nonlung-migrating helminth infection, house dust mite-induced allergic inflammation and influenza infection. Furthermore, we demonstrate that the induction of CD101hi tissue eosinophils is independent of IL-5 and IL-4 signaling, but is dependent on intact IL-13 signaling. These results suggest that IL-13 produced during helminth infection and other disease states promotes a pulmonary tissue-infiltrating program in eosinophils defined by high expression of CD101.

COPD patients with high blood eosinophil counts exhibit a lower rate of omicron infection and milder post-infection symptoms.

The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its subsequent Omicron variant has raised concerns for chronic obstructive pulmonary disease (COPD) patients due to the potential risk of disruptions to healthcare services and unknown comorbidities between COPD and Omicron. In this study, we conducted a follow-up investigation of 315 COPD patients during the Omicron outbreak at Shanxi Bethune Hospital to understand the impact of the pandemic on this vulnerable population. Among all patients, 228 were infected with Omicron, of which 82 needed hospitalizations. We found that COPD patients with high blood eosinophil (EOS) counts exhibited lower susceptibility to Omicron infection and were more likely to have milder symptoms that did not require hospitalization. Conversely, patients with low EOS counts showed higher rates of infection and hospitalization. Moreover, EOS count was positively correlated with T lymphocyte counts in hospitalized patients after Omicron infection, suggesting potential associations between EOS and specific immune responses in COPD patients during viral infections. Correlation analysis revealed a positive correlation between EOS count and lymphocyte and T-cells, and a negative correlation between EOS count and age, neutrophil, and C-reactive protein. Overall, our study contributes to the knowledge of COPD management during the COVID-19 Omicron outbreak and emphasizes the importance of considering individual immune profiles to improve care for COPD patients in the face of the ongoing global health crisis.

Eosinophilic leukemoid reaction in a child with mixed helminthiasis

Eosinophilic leukemoid reaction in a child with mixed helminthiasis

Comparison of extracellular vesicle isolation methods for the study of exosome cargo within Toxocara canis and Toxocara cati excretory secretory (TES) products

Toxocara is a genus of nematodes, which infects a variety of hosts, principally dogs and cats, with potential zoonotic risks to humans. Toxocara spp. larvae are capable of migrating throughout the host tissues, eliciting eosinophilic and granulomatous reactions, while surviving for extended periods of time, unchanged, in the host. It is postulated that larvae are capable of altering the host's immune response through the release of excretory-secretory products, containing both proteins and extracellular vesicles (EVs). The study of EVs has increased exponentially in recent years, largely due to their potential use as a diagnostic tool, and in molecular therapy. To this end, there have been multiple isolation methods described for the study of EVs. Here, we use nanoparticle tracking to compare the yield, size distribution, and % labelling of EV samples acquired through various reported methods, from larval cultures of Toxocara canis and T. cati containing Toxocara excretory-secretory products (TES). The methods tested include ultracentrifugation, polymer precipitation, magnetic immunoprecipitation, size exclusion chromatography, and ultrafiltration. Based on these findings, ultrafiltration produces the best results in terms of yield, expected particle size, and % labelling of sample. Transmission electron microscopy confirmed the presence of EVs with characteristic cup-shaped morphology. These findings can serve as a guide for those investigating EVs, particularly those released from multicellular organisms, such as helminths, for which few comparative analyses have been performed.

Resting and activated bovine neutrophils and eosinophils differ in their responses to adrenergic agonists

Polymorphonuclear cells (PMN) provide a rapid response to infection and tissue damage and stress can modify these critical innate immune defences. The study of adrenergic receptor (AR) expression and function in bovine PMNs is limited but both neutrophils and eosinophils express numerous AR genes but differ significantly in their expression of individual AR genes. A flow cytometric technique was developed to differentiate between bovine neutrophils and eosinophils so both neutrophil and eosinophil responses to adrenergic agonists could be analysed. Neutrophils and eosinophils displayed significantly different changes in CD11b, L-selectin, and CD44 expression when activated by bovine serum opsonized zymosan and recombinant bovine interferon gamma. The responses of activated and resting neutrophils and eosinophils were then compared following stimulation with endogenous adrenergic agonists, epinephrine (E) norepinephrine (NE), and synthetic agonists targeting α1-, α2-, or β-ARs. Both resting and activated neutrophils and eosinophils displayed differences in iROS, CD44, and L-selectin expression following stimulation with E and NE. Resting neutrophils displayed pro-inflammatory responses to both E and NE, while resting eosinophils displayed a pro-inflammatory response to only NE. No single synthetic adrenergic agonist fully recapitulated responses observed with either E or NE and responses to adrenergic agonists were dose-dependent. In conclusion, bovine eosinophils and neutrophils responded to multiple adrenergic agonists by altering expression of proteins involved in immune surveillance and pro-inflammatory responses. Significant differences in neutrophil and eosinophil responses to adrenergic agonists are consistent with their differences in AR gene expression. This highlights the importance of analysing separately these two PMN subpopulations when investigating the effects of either endogenous or synthetic AR agonists.

Neuromedin-U Mediates Rapid Activation of Airway Group 2 Innate Lymphoid Cells in Mild Asthma.

Rationale: In asthma, sputum group 2 innate lymphoid cells (ILC2s) are activated within 7 hours after allergen challenge. Neuroimmune interactions mediate rapid host responses at mucosal interfaces. In murine models of asthma, lung ILC2s colocalize to sensory neuronal termini expressing the neuropeptide neuromedin U (NMU), which stimulates type 2 (T2) cytokine secretion by ILC2s, with additive effects to alarmins invitro. Objectives: To investigate the effect of the NMU/NMUR1 (NMU receptor 1) axis on early activation of ILC2s in asthma. Methods: Subjects with mild asthma (n = 8) were enrolled in a diluent-controlled allergen inhalation challenge study. Sputum ILC2 expression of NMUR1 and T2 cytokines was enumerated by flow cytometry, and airway NMU levels were assessed by ELISA. This was compared with samples from subjects with moderate to severe asthma (n = 9). Flow sort-purified and ex vivo-expanded ILC2s were used for functional assays and transcriptomic analyses. Measurements and Main Results: Significant increases in sputum ILC2s expressing NMUR1 were detected 7 hours after allergen versus diluent challenge whereby the majority of NMUR1+ ILC2s expressed IL-5/IL-13. Sputum NMUR1+ ILC2 counts were significantly greater in mild versus moderate to severe asthma, and NMUR1+ ILC2s correlated inversely with the dose of inhaled corticosteroid in the latter group. Coculturing with alarmins upregulated NMUR1 in ILC2s, which was attenuated by dexamethasone. NMU-stimulated T2 cytokine expression by ILC2s, maximal at 6 hours, was abrogated by dexamethasone or specific signaling inhibitors for mitogen-activated protein kinase 1/2 and phosphoinositol 3-kinase but not the IL-33 signaling moiety MyD88 invitro. Conclusions: The NMU/NMUR1 axis stimulates rapid effects on ILC2s and may be an important early activator of these cells in eosinophilic inflammatory responses in asthma.

Comprehensive plasma cytokine and chemokine profiling in prurigo nodularis reveals endotypes in Type 2 inflammation

Prurigo nodularis (PN) is a chronic inflammatory skin disease that is associated with variability in peripheral blood eosinophil levels and response to T-helper 2 targeted therapies (Th2). Our objective was to determine whether circulating immune profiles with respect to type 2 inflammation differ by race and peripheral blood eosinophil count. Plasma from 56 PN patients and 13 matched healthy controls was assayed for 54 inflammatory biomarkers. We compared biomarker levels between PN and HCs, among PN patients based on absolute eosinophil count, and across racial groups in PN. Eleven biomarkers were elevated in PN versus HCs including interleukin (IL)-12/IL-23p40, tumor necrosis factor-alpha (TNF-α), Thymic stromal lymphopoietin (TSLP), and macrophage-derived chemokine (MDC/CCL22). Additionally, PN patients with AEC > 0.3 K cells/μL had higher Th2 markers (eotaxin, eotaxin-3, TSLP, MCP-4/CCL13), and African American PN patients had lower eosinophils, eotaxin, and eotaxin-3 versus Caucasian and Asian PN patients (p < 0.05 for all). Dupilumab responders had higher AEC (p < 0.01), were more likely to be Caucasian (p = 0.02) or Asian (p = 0.05) compared to African Americans, and more often had a history of atopy (p = 0.08). This study suggests that blood AEC > 0.3 K and Asian and Caucasian races are associated with Th2 skewed circulating immune profiles and response to Th2 targeted therapies.

Sensitization with Fungal Protease Allergen Establishes Long-Lived, Allergenic Th Cell Memory in the Lung.

Allergic asthma is a chronic inflammatory disease that affects millions of individuals worldwide. Exposure to allergens produced by a variety of otherwise harmless microbes, including fungi, predisposes individuals to immunopathologic disease upon subsequent encounters with allergen. We developed a mouse model that employs a purified protease produced by Aspergillus (Asp f 13) to investigate the contributions of CD4+ Th cells to recurrent lung inflammation. Notably, memory CD4+ T cells enhanced the eosinophil response of sensitized/rechallenged animals. In addition, memory CD4+ T cells maintained allergenic features, including expression of GATA-binding protein 3 and IL-5. Th2 memory T cells persisted in the peribronchiolar interstitium of the lung and expressed markers of tissue residence, such as CD69, CCR8, and IL-33R. Lastly, we identified a peptide epitope contained within Asp f 13 and generated a peptide-MHC class II tetramer. Using these tools, we further demonstrated the durability and exquisite sensitivity of memory T cells in promoting lung eosinophilia. Our data highlight important features of memory T cells that strengthen the notion that memory T cells are principal drivers of eosinophilic disease in murine models of allergic sensitization and episodic airway inflammation.

Eosinophils exhibit a unique transcriptional signature and increased sensitivity to IL-3-induced activation in response to colorectal cancer cells.

Eosinophils have been mainly studied in allergic diseases and parasitic infections. Nonetheless, eosinophils accumulate in a variety of solid tumors, including colorectal cancer, where their presence is associated with improved prognosis. Eosinophils can promote antitumor immunity through various mechanisms, including direct cytotoxicity toward tumor cells and promoting T-cell activation. However, the mechanisms by which tumor cells regulate eosinophil activities are largely unknown. Herein, we characterized the potential interactions between eosinophils and colorectal cancer cells using an unbiased transcriptomic and proteomic analyses approach. Human eosinophils were stimulated with colorectal cancer cell conditioned media, containing tumor cell secreted factors from multiple cancer cell lines. RNA sequencing analysis identified a "core" signature consisting of 101 genes that characterize a baseline transcriptional program for the response of human eosinophils to colorectal cancer cells. Among these, the increased expression of IL-3Rα and its βc chain was identified and validated at the protein level. Secreted factors from tumor cells potentiated IL-3-induced expression of the adhesion molecule CD11a in eosinophils. Combining proteomics analysis of tumor cell secreted factors with RNA sequencing revealed potential ligand-receptor pairs between tumor cells and eosinophils and the potential involvement of the adhesion molecule CD18 and F2RL3/PAR4. Subsequent functional analyses demonstrated that F2RL3/PAR4 suppresses eosinophil migration in response tumor cell secreted factors. These findings add to the growing body of evidence that eosinophils are conditioned by their local microenvironment. Identifying mechanisms by which eosinophils interact with tumor cells could lead to the development of new immunotherapies for colorectal cancer and other solid tumors.

Paradoxical eosinophilic and cytokine responses to oral corticosteroid treatment in patients with asthma exacerbations

BackgroundThymic stromal lymphopoietin (TSLP) orchestrates eosinophilic inflammation, which may increase in asthma exacerbations. On the contrary, miR-1 inhibits TSLP-mediated eosinophil trafficking in lung endothelium. Whether the balance of TSLP and miR-1 levels determines the response to oral corticosteroids during the treatment of asthma exacerbations remains unknown. ObjectiveTo investigate the involvement of TSLP/miR-1 axis in inflammatory response to OCS treatment for asthma exacerbations. MethodsWe measured the concentrations of TSLP and other inflammatory cytokines and miR-1 expression during acute asthmatic exacerbations treated with standard oral corticosteroids (OCS) in a real-life setting. Twenty eight consecutive patients with acute asthma exacerbations treated with OCS for 1 week at the Emergency Department (ED) were studied prospectively. Steroid responders (SR) were identified by a significant reduction in blood eosinophils, whereas paradoxical responders (PR) showed no markedly decreased or even increased absolute blood eosinophil counts after OCS treatment. Differential white blood cell counts, blood cytokine levels and miR-1 expression within and between groups were compared before and after OCS treatment. The baseline cytokine concentrations in both groups were compared with those of stable asthmatics (SA). ResultsOCS treatment significantly reduced TSLP levels in steroid responders whereas this effect did not occur in paradoxical responders (P = 0.006 and P = 0.742, respectively). In contrast, miR-1 expression was unchanged in steroid responders in response to OCS, whereas it was markedly reduced in the paradoxical responders, despite higher expression at baseline compared with stable asthmatics, which may account for slower resolution of the exacerbation. ConclusionsIn some asthmatic patients with acute exacerbations who do not suppress eosinophils after a course of OCS, there is a paradoxical decrease in plasma miR-1 and increase in TSLP compared with steroid responders, which may result in slower clinical recovery.