Eosinophilic Response Research Articles

Anti-IL-5 treatment, but not neutrophil interference, attenuates inflammation in a mixed granulocytic asthma mouse model, elicited by air pollution

IntroductionDiesel exhaust particles (DEP) have been proven to aggravate asthma pathogenesis. We previously demonstrated that concurrent exposure to house dust mite (HDM) and DEP in mice increases both eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) and also results in higher levels of neutrophil-recruiting chemokines and neutrophil extracellular trap (NET) formation compared to sole HDM, sole DEP or saline exposure. We aimed to evaluate whether treatment with anti-IL-5 can alleviate the asthmatic features in this mixed granulocytic asthma model. Moreover, we aimed to unravel whether neutrophils modulate the DEP-aggravated eosinophilic airway inflammation.Material and methodsFemale C57BL6/J mice were intranasally exposed to saline or HDM and DEP for 3 weeks (subacute model). Interference with eosinophils was performed by intraperitoneal administration of anti-IL-5 (TRFK5), which neutralizes IL-5. Interference with neutrophils and neutrophil elastase was performed by intraperitoneal anti-Ly6G and sivelestat administration, respectively. Outcome parameters included eosinophils subsets (homeostatic EOS and inflammatory EOS), proinflammatory cytokines, goblet cell hyperplasia and airway hyperresponsiveness.ResultsThe administration of anti-IL-5 significantly decreased eosinophilic responses, affecting both inflammatory and homeostatic eosinophil subsets, upon subacute HDM + DEP exposure while BAL neutrophils, NET formation and other asthma features remained present. Neutrophils were significantly reduced after anti-Ly6G administration in BALF, lung and blood without affecting the eosinophilic inflammation upon HDM + DEP exposure. Sivelestat treatment tended to decrease BALF inflammation, including eosinophils, upon HDM + DEP exposure, but did not affect lung inflammation.ConclusionInhibition of IL-5 signalling, but not neutrophil interventions, significantly attenuates eosinophilic inflammation in a mouse model of mixed granulocytic asthma, elicited by air pollution exposure.

Celiac disease, non-celiac wheat sensitivity, wheat allergy - clinical and diagnostic aspects.

In recent years, wheat- and gluten-free diets have increased in demand due to reported increases in various conditions reported to be driven by ingredients of these food products. Celiac disease, wheat allergy and non-celiac wheat sensitivity constitute the three main categories of wheat-related disorders. Celiac disease is a well-characterized immune-mediated disease caused by immune reaction against specific gliadin epitopes, the main protein in wheat. Screening studies of samples collected over time bring evidence that there is a true increase in prevalence not only driven by increased testing activity. Clinical presentation of CeD is diverse and there is an increased risk of autoimmune co-morbidities. Wheat allergy consists of IgE- and non-IgE-mediated reactions, driven by Th2-cells directing eosinophil and basophil responses. Rapid IgE-mediated reactions are characterized by specific IgE antibodies in conjunction with symptoms originating especially from the respiratory and gastrointestinal tract. There is an increased risk of other allergies and the majority recover during adolescence. Non-IgE-mediated wheat allergy is a less-well defined condition, which is often diagnostically challenging due to a longer interval between exposure and symptoms and lack of non-invasive biomarkers. In this condition, wheat as a trigger needs to be established by exclusion followed by dietary challenge. Non-celiac wheat sensitivity, despite being the most recently recognized, has the highest reported prevalence among the three wheat-related entities. It remains, however, particularly poorly characterized due to unclear pathophysiology and lack of diagnostic markers. This narrative review will scrutinize the shared and distinct clinical features of the three wheat-related conditions, focusing on epidemiology, clinical presentation, co-morbidities, diagnosis, treatment and prognosis.

Assessing the Prevalence and Histopathology of Linguatula serrata Infection of Camels and Cattle in Zabol County, Sistan and Baluchestan Province, Iran.

Linguatula serrata (L. serrata) is a worldwide zoonotic parasite and one of the most widespread pathogens. This study aimed to determine the prevalence of L. serrata in cattle and camels of Zabol County, Sistan and Baluchestan Province, Iran. From March 2014 to February 2021, 300 cattle (48 female and 252 male) and 300 camels (31 female and 269 male) were examined at the Zabol slaughterhouse, encompassing different age groups. The cattle breeds were indigenous (native Sistani breeds) and non-indigenous (breeds introduced from external regions), while all the camels were native breeds. To identify L. serrata nymphs, three samples of mesenteric lymph nodes (MLNs) were meticulously collected in phosphate-buffered saline immediately after slaughtering. According to the results, 4.33% (13/300) of cattle were infected with L. serrata, with six females and seven males infected. There was a significant difference in the prevalence of infection between females (6/48, 12.5%) and males (7/252, 2.77%) of cattle (p=0.009). Moreover, cattle older than 3years had significantly more infections with L. serrata nymphs (16.07%, 9/56) than cattle of other ages (p<0.001). Compared to other seasons, autumn showed a high prevalence of parasites (8.1%, 6/74) (p=0.017). Regarding the camels, only 3.66% (11/300) were infected, and there was no significant difference in infection rates between male and female camels or between seasons (p>0.05). The infection rate was higher in camels older than 3years (n=9) than in camels younger than 3years (p<0.05). The MLNs of infected cattle were edematous, red, enlarged and characterized by an eosinophilic granulomatous reaction with mononuclear inflammatory cells. The present study had low rates of L. serrata infection because the farms were clean, and cattle and camels did not have contact with final hosts such as dogs and wild canids. This suggests that their management strategies, including secure and preventative measures, were effective.

Mechanisms underlying Th2-dominant pneumonia caused by plastic pollution derivatives (PPD): A molecular toxicology investigation that encompasses gut microbiomics and lung metabolomics

An investigation was conducted by researchers on how dibutyl phthalate (DBP) and polystyrene microplastics (PS-MP) influence the development of pneumonia using a mouse model. For a duration of five weeks, the mice were subjected to exposure of DBP (30 mg/kg/day) and PS-MP (0.1 mg/day). The findings indicated notable pathological alterations in airway tissues, increased oxidative stress levels, and intensified inflammation, thereby establishing a connection between plastic pollution and pneumonia. Further examination indicated the involvement of ferroptosis and oxidative stress in the progression of the disease. Administration of deferoxamine (DFO) (100 mg/kg) resulted in symptom relief and reduced pathological alterations, as validated by metabolomic investigations. Increased levels of reactive oxygen species (ROS) triggered a Th2-mediated eosinophilic inflammatory response, marked by elevated IL-4 and reduced IFN-γ via the NFκB pathway. Moreover, analyses of the gut microbiome and metabolomics demonstrated that PPD modifies microbial populations and pulmonary metabolism, linking its effects on pneumonia through the gut-lung axis. This research highlights the health hazards associated with plastic pollution and proposes a framework for tackling these issues.

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

Chitinase 3-Like-1/BRP-39 regulates extracellular matrix remodeling during allergic fungal asthma

Abstract We previously reported that fungal-sensitized human asthmatics had higher levels of the chitinase-like protein YKL-40 in sputum than non-fungal sensitized asthmatics. Unexpectedly, we found that mice deficient in BRP-39 (Chi3l1-/- mice; the murine ortholog of human YKL-40) had increased airway hyperreactivity (AHR) during experimental allergic fungal asthma, despite no correlation with classic drivers of AHR (type 2 and eosinophilic responses). BRP-39 has been reported to bind lectins and complex carbohydrates and is involved in non-immune processes such as cell proliferation, angiogenesis and tissue remodeling. The extracellular matrix (ECM) of the lung is mainly comprised of collagen and elastin that provides elasticity and resilience to compressive and expanding forces. We found that Chi3l1-/- mice subjected to allergic fungal asthma demonstrated restrictions in lung mechanics due to increased elastic stiffness in the conducting airways and the alveolar/parenchymal compartment. This correlated with increased levels of collagen and elastin in mutant mice. ECM enzymes involved in matrix remodeling of collagen and elastin, such as matrix metalloproteinases (MMPs) 2, 3, 9, and 12, were reduced in mutant mice. We further identified BRP-39 dependent differences in MMP secretion by stimulating primary lung fibroblasts. Ultimately, these findings highlight BRP-39 as a crucial regulator of MMPs needed to turnover lung ECM proteins during the progression of allergic fungal asthma.

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.