The immunobiology of eosinophils

Type 2 airway inflammation in COPD

Globally, nearly 400 million persons have COPD, and COPD is one of the leading causes of hospitalisation and mortality across the world. While it has been long-recognised that COPD is an inflammatory lung disease, dissimilar to asthma, type 2 inflammation was thought to play a minor role. However, recent studies suggest that in approximately one third of patients with COPD, type 2 inflammation may be an important driver of disease and a potential therapeutic target. Importantly, the immune cells and molecules involved in COPD-related type 2 immunity may be significantly different from those observed in severe asthma. Here, we identify the important molecules and effector immune cells involved in type 2 airway inflammation in COPD, discuss the recent therapeutic trial results of biologicals that have targeted these pathways and explore the future of therapeutic development of type 2 immune modulators in COPD.

Morphological and quantitative analysis of leukocytes in free-living Australian black flying foxes (Pteropus alecto)

The black flying fox (Pteropus alecto) is a natural reservoir for Hendra virus, a paramyxovirus that causes fatal infections in humans and horses in Australia. Increased excretion of Hendra virus by flying foxes has been hypothesized to be associated with physiological or energetic stress in the reservoir hosts. The objective of this study was to explore the leukocyte profiles of wild-caught P. alecto, with a focus on describing the morphology of each cell type to facilitate identification for clinical purposes and future virus spillover research. To this end, we have created an atlas of images displaying the commonly observed morphological variations across each cell type. We provide quantitative and morphological information regarding the leukocyte profiles in bats captured at two roost sites located in Redcliffe and Toowoomba, Queensland, Australia, over the course of two years. We examined the morphology of leukocytes, platelets, and erythrocytes of P. alecto using cytochemical staining and characterization of blood films through light microscopy. Leukocyte profiles were broadly consistent with previous studies of P. alecto and other Pteropus species. A small proportion of individual samples presented evidence of hemoparasitic infection or leukocyte morphological traits that are relevant for future research on bat health, including unique large granular lymphocytes. Considering hematology is done by visual inspection of blood smears, examples of the varied cell morphologies are included as a visual guide. To the best of our knowledge, this study provides the first qualitative assessment of P. alecto leukocytes, as well as the first set of published hematology reference images for this species.

Role of IL-25 on Eosinophils in the Initiation of Th2 Responses in Allergic Asthma

Background

Eosinophils act as a secondary antigen-presenting cell (APC) to stimulate Th cell responses against antigens. IL-25 plays a significant role in eosinophil activation in allergic asthma. The role of IL-25 on the classic APC functions of dendritic cells has been elucidated. However, whether IL-25 facilitates eosinophils for antigen presentation is unknown.

Objective

To elucidate the role of IL-25 on eosinophils antigen presenting function during allergic asthma and its related mechanism.

Methods

Eosinophils from allergic asthma subjects were cultured with IL-25 and HDM to identify the co-stimulator molecules expression. Co-cultures of patient eosinophils and autologous naïve CD4⁺ T cells in the same culture system were to explore whether eosinophils had the capacity to promote Th cell differentiation in response to IL-25 engagement. In asthma mouse model, IL-25^-/- mice were exposed to HDM to investigate the effect of IL-25 on eosinophils during the sensitization phase. The impact of IL-25 on the capacity for eosinophils taking up antigens was evaluated. Mouse bone marrow derived eosinophils (BmEOS) were co-cultured with naïve CD4⁺T cells sorted from spleens under HDM and IL-25 stimulation to identify T cell differentiation.

Results

IL-25 upregulated HLA-DR, PD-L1, and OX-40L expression on eosinophils from allergic asthma patients. IL-25 and HDM co-sensitized eosinophils promoted Th2 differentiation. In mouse model, IL-25^-/- mice experienced restrained allergic pulmonary inflammation and reduced eosinophils recruitment and antigen uptake capacity during the early sensitization phase. In vitro, IL-25 promoted antigen uptake by eosinophils. In BmEOS and naïve CD4⁺T cells co-culture, IL-25 accreted the proportion of CD4⁺Th2 cells, which was absent in CD4⁺T cells culture alone.

Conclusion

Our data identify a novel role of IL-25 in enhancing eosinophils antigen uptake and co-stimulator molecules expression to induce Th2 priming in the context of allergic inflammation.

Feline ophthalmomyiasis externa caused by Cuterebra larvae: four cases (2005-2020)

CASE SERIES SUMMARY

Described are four cats diagnosed with ophthalmomyiasis externa caused by Cuterebra larvae. Medical records were retrospectively reviewed to identify cats with ophthalmomyiasis externa between 2005 and 2020 at Cornell University Hospital for Animals. Signalment, history, clinical and diagnostic findings, treatment and outcome were recorded. All cats were young (< 3 years of age), had outdoor access and were initially examined during the summer months. All cases had unilateral disease with the right eye affected. Two cases had nictitating membrane lesions and two had orbital disease. Concurrent superficial corneal ulceration was present in three cats. Two cats suffered from pyrexia, suspected secondary to inflammation from the larval infestation. Successful larval removal was performed in all cats, which resulted in improvement of discomfort and clinical signs. A corneal ulcer persisted in one cat, which was lost to follow-up prior to ulcer resolution. Parasite identification confirmed Cuterebra species infestation in all cases.

RELEVANCE AND NOVEL INFORMATION

To the authors' knowledge, this is the first report of feline ophthalmomyiasis externa caused by Cuterebra species. Parasite removal was successful in restoring comfort and resolving clinical signs in all cats with adequate follow-up information.

The Role of Tumor Microenvironment in the Pathogenesis of Sézary Syndrome

Sézary syndrome is an aggressive leukemic variant of cutaneous T-cell lymphomas, characterized by erythroderma, lymphadenopathy, and peripheral blood involvement by CD4+ malignant T-cells. The pathogenesis of Sézary syndrome is not fully understood. However, the course of the disease is strongly influenced by the tumor microenvironment, which is altered by a combination of cytokines, chemokines, and growth factors. The crosstalk between malignant and reactive cells affects the immunologic response against tumor cells causing immune dysregulation. This review focuses on the interaction of malignant Sézary cells and the tumor microenvironment.

Antimicrobial Activity of Human Eosinophil Granule Proteins

Eosinophils secrete a number of proinflammatory mediators that include cytokines, chemokines, and granule proteins which are responsible for the initiation and maintenance of inflammatory responses. The eosinophil granule proteins, ECP, EDN, MBP, and EPO, possess antimicrobial activity against bacteria, helminths, protozoa, and viruses. In this chapter, we describe various assays used to detect and quantitate the antimicrobial activities of eosinophil granule proteins, particularly ECP and EDN. We have taken a model organism for each assay and described the method for antiviral, antihelminthic, antiprotozoan, and antibacterial activity of purified eosinophil granule proteins.

The impacts of body mass on immune cell concentrations in birds

Body mass affects many biological traits, but its impacts on immune defences are fairly unknown. Recent research on mammals found that neutrophil concentrations disproportionately increased (scaled hypermetrically) with body mass, a result not predicted by any existing theory. Although the scaling relationship for mammals might predict how leucocyte concentrations scale with body mass in other vertebrates, vertebrate classes are distinct in many ways that might affect their current and historic interactions with parasites and hence the evolution of their immune systems. Subsequently, here, we asked which existing scaling hypothesis best-predicts relationships between body mass and lymphocyte, eosinophil and heterophil concentrations-the avian functional equivalent of neutrophils-among more than 100 species of birds. We then examined the predictive power of body mass relative to life-history variation, as extensive literature indicates that the timing of key life events has influenced immune system variation among species. Finally, we ask whether avian scaling patterns differ from the patterns we observed in mammals. We found that an intercept-only model best explained lymphocyte and eosinophil concentrations among birds, indicating that the concentrations of these cell types were both independent of body mass. For heterophils, however, body mass explained 31% of the variation in concentrations among species, much more than life-history variation (4%). As with mammalian neutrophils, avian heterophils scaled hypermetrically (b = 0.19 ± 0.05), but more steeply than mammals (approx. 1.5 ×; 0.11 ± 0.03). As such, we discuss why birds might require more broadly protective cells compared to mammals of the same body size. Overall, body mass appears to have strong influences on the architecture of immune systems.

Interplay Between the IL-33/ST2 Axis and Bone Marrow ILC2s in Protease Allergen-Induced IL-5-Dependent Eosinophilia

Background: Eosinophils develop from CD34⁺ progenitor cells in the bone marrow under the influence of interleukin (IL)-5. Several cell types produce IL-5, including type 2 innate lymphoid cells (ILC2s). The alarmin cytokine IL-33 is known to activate ILC2s in mucosal tissues, but little is known about IL-33-responsive ILC2s in the bone marrow in allergen-induced airway inflammation.

Methods: Wild type (WT) and Rag1 deficient (Rag1^−/−) mice, which lack mature T and B cells, received intranasal doses of papain to induce acute allergic inflammation. In some experiments, mice were pre-treated with anti-IL-5 prior to the papain challenge. Furthermore, recombinant IL-33 was administered to WT mice, Rag1^−/− mice, lymphocyte deficient mice (Rag2^−/−Il2rg^−/−) and to ex vivo whole bone marrow cultures. Bone marrow eosinophils and ILC2s were analyzed by flow cytometry. Eosinophil count was assessed by differential cell count and secreted IL-5 from bone marrow cells by ELISA.

Results: Intranasal administration of papain or IL-33 increased the number of mature eosinophils in the bone marrow despite the absence of adaptive immune cells in Rag1^−/− mice. In parallel, an increased number of eosinophils was observed in the airways together with elevated levels of Eotaxin-2/CCL24. Bone marrow ILC2s were increased after papain or IL-33 administration, whereas ILC2s was found to be increased at baseline in Rag1^−/− mice compared to WT mice. An upregulation of the IL-33 receptor (ST2) expression on bone marrow ILC2s was observed after papain challenge in both Rag1^−/− and WT mice which correlated to increased number of bone marrow eosinophilia. Furthermore, an increased number of ST2⁺ mature eosinophils in the bone marrow was observed after papain challenge, which was further dependent on IL-5. In addition, bone marrow-derived ILC2s from both mouse strains produced large amounts of IL-5 ex vivo after IL-33 stimulation of whole bone marrow cultures. In contrast, IL-33-induced bone marrow and airway eosinophilia were abolished in the absence of ILC2s in Rag2^−/−Il2rg^−/− mice and no production of IL-5 was detected in IL-33-stimulated bone marrow cultures.

Conclusion: These findings establish bone marrow ILC2s and the IL-33/ST2 axis as promising targets for modulation of uncontrolled IL-5-dependent eosinophilic diseases including asthma.

House Dust Mite Induces Bone Marrow IL-33-Responsive ILC2s and TH Cells

Type 2 innate lymphoid cells (ILC2s) and their adaptive counterpart type 2 T helper (TH2) cells respond to interleukin-33 (IL-33) by producing IL-5, which is a crucial cytokine for eosinophil development in the bone marrow. The aim of this study was to determine if bone marrow ILC2s, TH cells, and eosinophils are locally regulated by IL-33 in terms of number and activation upon exposure to the common aeroallergen house dust mite (HDM). Mice that were sensitized and challenged with HDM by intranasal exposures induced eosinophil development in the bone marrow with an initial increase of IL5Rα+ eosinophil progenitors, following elevated numbers of mature eosinophils and the induction of airway eosinophilia. Bone marrow ILC2s, TH2, and eosinophils all responded to HDM challenge by increased IL-33 receptor (ST2) expression. However, only ILC2s, but not TH cells, revealed increased ST2 expression at the onset of eosinophil development, which significantly correlated with the number of eosinophil progenitors. In summary, our findings suggest that airway allergen challenges with HDM activates IL-33-responsive ILC2s, TH cells, and eosinophils locally in the bone marrow. Targeting the IL-33/ST2 axis in allergic diseases including asthma may be beneficial by decreasing eosinophil production in the bone marrow.

Eosinophilic Esophagitis in Adults: A Concise Overview of an Evolving Disease

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease that encompasses esophageal symptoms along with eosinophilic infiltration of the esophageal epithelium. EoE is an evolving disease that has been a subject of interest to many researchers since the first studies recognized this condition as a new and distinct clinicopathological entity 25 years ago. Clinical presentation in adult patients may include dysphagia, food impaction, vomiting, and reflux symptoms. The diagnosis of EoE is based on the combination of clinical history suggestive of esophageal dysfunction, endoscopic features indicative of the disease, and histology revealing eosinophilic infiltration of the esophageal epithelium that persists after a trial of proton pump inhibitor therapy along with the exclusion of other disorders that may be associated with esophageal tissue eosinophilia. The interplay between EoE and gastroesophageal reflux disease (GERD) is complex, and differentiating these two conditions continues to be difficult and challenging in clinical practice. The mainstay treatment includes dietary modification, topical steroids, and/or endoscopic dilation. The primary care physician (PCP) plays an important role in improving patient care and quality of life by ensuring early referral and participating in management and follow-up. This article provides an overview of the current knowledge base regarding the disease including epidemiology, genetics, pathogenesis, common clinical presentations, the interplay between EoE and GERD, diagnostic approaches, and therapeutic options available to the PCP.

Antibody blockade of Dectin-2 suppresses house dust mite-induced Th2 cytokine production in dendritic cell- and monocyte-depleted peripheral blood mononuclear cell co-cultures from asthma patients

Background

Dectin-2, which is a C-type lectin, interacts with the house dust mite (HDM) Dermatophagoides pteronyssinus allergen. This study aimed to investigate whether Dectin-2 blockade by antagonistic monoclonal antibodies (MoAbs) attenuates HDM-induced allergic responses.

Methods

Two anti-Dectin-2 MoAbs were generated and validated for specific binding to Dectin-2 Fc fusion protein (Dectin-2.Fc) and inhibition of Dectin-2.Fc/HDM interaction. Patients with asthma exhibiting high titers of anti-D. pteronyssinus IgE were enrolled. Peripheral blood mononuclear cells with depleted CD14⁺ monocytes were obtained from these patients and co-cultured with autologous monocyte-derived conventional dendritic cells in the presence of D. pteronyssinus or its group 2 allergens (Der p 2). Interleukin (IL)-5 and IL-13 levels in the culture supernatants were determined using ELISA in the presence or absence of anti-Dectin-2 MoAbs.

Results

Two MoAbs, 6A4G7 and 17A1D10, showed specific binding to recombinant Dectin-2.Fc and inhibited HDM binding to Dectin-2.Fc. Both anti-Dectin-2 MoAbs inhibited IL-5 and IL-13 production in co-cultures with Der p 2 stimulation in a dose-dependent manner. 6A4G7 and 17A1D10 (3 μg/mL) significantly inhibited Der p 2-induced (3 μg/mL) IL-5 production by 69.7 and 86.4% and IL-13 production by 84.0 and 81.4%, respectively. Moreover, this inhibitory effect of the two MoAbs remained significant in the presence of D. pteronyssinus.

Conclusions

Anti-Dectin-2 MoAbs significantly inhibited HDM-induced allergic responses in vitro and therefore have the potential to become therapeutic agents in mite-induced allergic diseases.

Prognostic impact of eosinophils in mastocytosis: analysis of 2350 patients collected in the ECNM Registry

Systemic mastocytosis (SM) is frequently associated with eosinophilia. To examine its prevalence and clinical impact in all WHO classification-based subcategories, we analyzed eosinophil counts in 2350 mastocytosis patients using the dataset of the European Competence Network on Mastocytosis. Ninety percent of patients had normal eosinophil counts, 6.8% mild eosinophilia (0.5-1.5 × 10⁹/l), and 3.1% hypereosinophilia (HE; >1.5 × 10⁹/l). Eosinophilia/HE were mainly present in patients with advanced SM (17%/19%), and only rarely recorded in patients with indolent and smoldering SM (5%/1%), and some patients with cutaneous mastocytosis. The eosinophil count correlated with organomegaly, dysmyelopoiesis, and the WHO classification, but not with mediator-related symptoms or allergy. Eosinophilia at diagnosis had a strong prognostic impact (p < 0.0001) on overall survival (OS) and progression-free survival (PFS), with a 10-year OS of 19% for patients with HE, 70% for those with mild eosinophilia, and 88% for patients with normal eosinophil counts. In 89% of patients with follow-up data (n = 1430, censored at start of cytoreductive therapy), eosinophils remained stable. In those with changing eosinophil counts (increase/decrease or mixed pattern), OS and PFS were inferior compared with patients with stable eosinophil counts. In conclusion, eosinophilia and HE are more prevalent in advanced SM and are predictors of a worse outcome.

What Are the Clinical Features and Etiology of Eosinophilic Liver Infiltration?

Background/Aims

Although eosinophilic liver infiltration (ELI) is not rare, few data exist regarding its clinical characteristics and etiology. Therefore, we evaluated these aspects to better understand the clinical implications of this lesion type, which is reasonably common in Korea.

Methods

Patients suspected of having ELI, based on abdominal computed tomography results obtained between January 2010 and September 2017, were enrolled in this retrospective study. The presumptive etiologies of ELI were categorized as parasite infections, hypereosinophilic syndrome (HES), eosinophilic granulomatosis with polyangiitis (EGPA), malignancies, and unidentified. Clinical courses and treatment responses were also evaluated.

Results

The mean age of the enrolled patients (male, 237/328) was 62 years. Most patients (63%) were diagnosed incidentally and had peripheral eosinophilia (90%). Only 38% of the enrolled patients (n=126) underwent further evaluations to elucidate the etiology of the suspected ELI; 82 (25%) had parasite infections, 31 (9%) had HES, five (2%) had EGPA, and five (2%) had drug reactions in conjunction with eosinophilia and systemic symptoms. Almost half of the other enrolled patients had cancer. Radiologic resolution was achieved in 191 patients (61%; median time to radiologic resolution, 185 days). Resolution of peripheral eosinophilia was achieved in 220 patients (79%). In most cases, the course of ELI was benign.

Conclusions

This large ELI study is unique in that the incidence rate, underlying diseases, and clinical courses were comprehensively evaluated. Clinicians should investigate the etiology of ELI, as several of the underlying diseases require intervention rather than observation.

Eosinophilic colitis: A clinical review

Eosinophilic colitis is a rare entity characterized by the presence of a high eosinophilic infiltrate into the colonic wall in symptomatic patients, more often presenting with abdominal pain or diarrhea. These characteristics distinguish eosinophilic colitis from primary colonic eosinophilia, in which patients are asymptomatic. Primary colonic eosinophilia does not need any therapy, while eosinophilic colitis requires a strict treatment, similar to that of the more codified chronic intestinal inflammatory diseases. To date the lack of codified guidelines regarding the diagnostic criteria and the eosinophil threshold values for each colonic segment are the main diagnostic challenge for eosinophilic colitis. In addition, eosinophilic colitis is a diagnosis of exclusion, once all other causes of colonic eosinophilia (food allergens, infections, drugs, etc.) have been excluded. Several treatment options are available for eosinophilic colitis, although the evidence for most of them is limited to case reports and small case series. We examine the epidemiology, etiology, pathophysiology, diagnostic criteria and therapeutic options of eosinophilic colitis reporting recent evidence from the current literature.

An Approach to the Evaluation of Persistent Hypereosinophilia in Pediatric Patients

Hypereosinophilia (HE) is currently defined by a peripheral blood absolute eosinophil count (AEC) of ≥1,500 cells/microL. Although mild blood eosinophilia (AEC 500–1,500 cells/microL) is observed relatively frequently within the pediatric population, persistent HE is uncommon and should prompt additional clinical evaluation. While the clinical manifestations and underlying etiologies of HE in adults have been well-characterized, there is a paucity of data on HE in children. Limited evidence suggests that many similarities between adult and pediatric HE likely exist, but some important differences remain between these populations. The evaluation of HE in children can be challenging given the broad differential diagnosis, which includes primary hematologic disorders and secondary eosinophilia in which the increased eosinophil levels are propagated by disease states that promote eosinophil production and survival. On the basis of the underlying etiology, clinical manifestations can range from benign, self-resolving elevations in the AEC to life-threatening disorders with the potential for significant end-organ damage. Given the broad differential diagnosis of HE, it remains essential to systematically approach the evaluation of unexplained HE in children. This review will discuss the differential diagnosis for pediatric HE, highlighting etiologies that are more prevalent within the pediatric population. Additionally, a summary of the epidemiology of pediatric HE will be presented, with focus on some of the differences that exist between pediatric and adult HE. Finally, a directed approach to the diagnostic evaluation of children with HE will be discussed.

Progress in the understanding of the pathology of allergic asthma and the potential of fruit proanthocyanidins as modulators of airway inflammation

Allergic asthma is a chronic inflammatory lung disease characterized by sensitization of the airways, and the development of immunoglobulin E antibodies, to benign antigens. The established pathophysiology of asthma includes recurrent lung epithelial inflammation, excessive mucus production, bronchial smooth muscle hyperreactivity, and chronic lung tissue remodeling, resulting in reversible airflow restriction. Immune cells, including eosinophils and the recently characterized type 2 innate lymphoid cells, infiltrate into the lung tissue as part of the inflammatory response in allergic asthma. It is well established that a diet high in fruits and vegetables results in a reduction of the risk of developing inflammatory diseases. Secondary plant metabolites, such as proanthocyanidins which are found in apples, blackcurrants, boysenberries, cranberries, and grapes, have shown promising results in reducing or preventing allergic asthma airway inflammation. Recent evidence has also highlighted the importance of microbiome-mediated metabolism of plant polyphenols in modulating the immune system. In this review, we will discuss advances in our understanding of the pathophysiology of allergic asthma, including the role of the microbiome in lung immune function, and how proanthocyanidins modulate the airway inflammation. We will highlight the potential of dietary proanthocyanidins to impact on allergic asthma and the immune system.

Elevated Systemic Levels of Eosinophil, Neutrophil, and Mast Cell Granular Proteins in Strongyloides Stercoralis Infection that Diminish following Treatment

Infection with the helminth parasite Strongyloides stercoralis (Ss) is commonly clinically asymptomatic that is often accompanied by peripheral eosinophilia. Granulocytes are activated during helminth infection and can act as immune effector cells. Plasma levels of eosinophil and neutrophil granular proteins convey an indirect measure of granulocyte degranulation and are prominently augmented in numerous helminth-infected patients. In this study, we sought to examine the levels of eosinophil, neutrophil, and mast cell activation-associated granule proteins in asymptomatic Ss infection and to understand their kinetics following anthelmintic therapy. To this end, we measured the plasma levels of eosinophil cationic protein, eosinophil-derived neurotoxin, eosinophil peroxidase, eosinophil major basic protein, neutrophil elastase, myeloperoxidase, neutrophil proteinase-3, mast cell tryptase, leukotriene C4, and mast cell carboxypeptidase-A3 in individuals with asymptomatic Ss infection or without Ss infection [uninfected (UN)]. We also estimated the levels of all of these analytes in infected individuals following definitive treatment of Ss infection. We demonstrated that those infected individuals have significantly enhanced plasma levels of eosinophil cationic protein, eosinophil-derived neurotoxin, eosinophil peroxidase, eosinophil major basic protein, elastase, myeloperoxidase, mast cell tryptase, leukotriene C4, and carboxypeptidase-A3 compared to UN individuals. Following the treatment of Ss infection, each of these granulocyte-associated proteins drops significantly. Our data suggest that eosinophil, neutrophil, and mast cell activation may play a role in the response to Ss infection.

Creating a multi-center rare disease consortium - the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR)

 Eosinophilic gastrointestinal disorders (EGIDs) affect various segments of the gastrointestinal tract. Since these disorders are rare, collaboration is essential to enroll subjects in clinical studies and study the broader population. The Rare Diseases Clinical Research Network (RDCRN), a program of the National Center for Advancing Translational Sciences (NCATS), funded the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR) in 2014 to advance the field of EGIDs. CEGIR facilitates collaboration among various centers, subspecialties, patients, professional organizations and patient-advocacy groups and includes 14 clinical sites. It has successfully initiated two large multi-center clinical studies looking to refine EGID diagnoses and management. Several pilot studies are underway that focus on various aspects of EGIDs including novel therapeutic interventions, diagnostic and monitoring methods, and the role of the microbiome in pathogenesis. CEGIR currently nurtures five physician-scholars through a career training development program and has published more than 40 manuscripts since its inception. This review focuses on CEGIR's operating model and progress and how it facilitates a framework for exchange of ideas and stimulates research and innovation. This consortium provides a model for progress on other potential clinical areas.

Differential Location and Distribution of Hepatic Immune Cells

The liver is one of the main organs in the body, performing several metabolic and immunological functions that are indispensable to the organism. The liver is strategically positioned in the abdominal cavity between the intestine and the systemic circulation. Due to its location, the liver is continually exposed to nutritional insults, microbiota products from the intestinal tract, and to toxic substances. Hepatocytes are the major functional constituents of the hepatic lobes, and perform most of the liver’s secretory and synthesizing functions, although another important cell population sustains the vitality of the organ: the hepatic immune cells. Liver immune cells play a fundamental role in host immune responses and exquisite mechanisms are necessary to govern the density and the location of the different hepatic leukocytes. Here we discuss the location of these pivotal cells within the different liver compartments, and how their frequency and tissular location can dictate the fate of liver immune responses.

Patient profiles and clinical utility of mepolizumab in severe eosinophilic asthma

Mepolizumab (Nucala^®) is an effective and specific anti-eosinophil molecular therapy that has recently been approved as add-on therapy for the management of severe eosinophilic asthma by the US Food and Drug Administration (FDA), European Medicines Agency (EMA; European Union) and more recently National Institute for Health and Care Excellence (NICE; UK). It is one of several molecular therapies in development for this indication and is illustrative of the strategic trajectory for pharmaceutical drug development taken over the past decade in several disease areas. Molecular therapies offer the prospect of improved specificity and effectiveness of biological effect. However, this necessitates a clear understanding of the underlying mechanistic pathways underpinning pathological processes, to inform drug development that yields novel more efficacious treatment options with a better clinical profile than existing agents. For the first time, utilization of molecular therapies in clinical trials is providing a novel in vivo model to characterize the association between specific pathways and clinical disease expression. It is increasingly recognized that asthma exhibits both clinical and pathological heterogeneity. It follows that a one-size-fits-all approach will not be appropriate and cost-effectiveness may only be achieved by identifying responder subgroups. This so-called personalized approach to therapy is being supported by the parallel development of companion biomarkers for clinical application. In this review, the author summarizes the clinical studies, their interpretation and the lessons learnt with mepolizumab that have informed our understanding of the approach to personalized molecular therapy in asthma.

Blackcurrant anthocyanins modulate CCL11 secretion and suppress allergic airway inflammation

CCL11, a chemokine, is linked to the early development of airways eosinophilia in allergic asthma. Therefore, CCL11 production is a target for abrogating eosinophilic-driven airway inflammation. Blackcurrants are high in compounds that regulate inflammation, particularly anthocyanins. In this study, we investigated the effect of oral blackcurrant supplementation on allergen-induced eosinophilia and CCL11 production; we also profiled key compounds in blackcurrants that were linked to this effect. Ten milligram per kilogram (total anthocyanins) of a commercially available, anthocyanin-rich New Zealand "Ben Ard" blackcurrant extract ("Currantex 30") attenuated ovalbumin-induced inflammation, eosinophilia (by 52.45 ± 38.50%), and CCL11 production (by 48.55 ± 28.56%) in a mouse model of acute allergic lung inflammation. Ten blackcurrant polyphenolic extracts were also found to suppress CCL11 secretion by stimulated human lung epithelial cells in vitro. Correlation analysis identified potential blackcurrant polyphenolic anthocyanin constituents specifically delphinidins and cyanidins, involved in CCL11 suppression. Our findings show oral supplementation with New Zealand blackcurrant is effective in reducing lung inflammation, and highlight the potential benefit of developing cultivars with specific polyphenolic profiles for the creation of functional foods with desirable biological activity.

Eosinophilic colitis in children

INTRODUCTION

Eosinophilic colitis, which is a rare form of eosinophilic gastrointestinal diseases, occurs as primary and secondary allergic eosinophilic colitis of the gastrointestinal tract infection, inflammatory bowel disease, celiac disease, and vasculitis. The diagnosis is based on a significant amount of eosinophils in the inflammatory infiltrate of the colon wall.

AIM

To analyze the clinical picture taking into account comorbidities and endoscopic picture in children with eosinophilic colitis.

MATERIAL AND METHODS

The test group consisted of 43 children, the average age - 12.1 years diagnosed with eosinophilic colitis (according to the Whitington scale) hospitalized in the Gastroenterology Unit, Department of Pediatrics of the Medical University of Silesia in Katowice. Testing for food allergies, celiac disease, inflammatory bowel disease, gastrointestinal diseases and parasitic diseases was performed in the group of children and the analysis concerned the intensity of eosinophilic infiltration of the colon mucosa with the severity of clinical symptoms, endoscopic picture, the presence of inflammatory bowel disease, and food allergy.

RESULTS

Half of the tested children suffered from isolated eosinophilic colitis but the rest of them had eosinophilic infiltrate with inflammatory bowel disease more often, however, the Crohn's disease. The endoscopic image was uncharacteristic, and grade III in the Whitington scale was predominant in the histopathological examination, in most cases located in the entire large intestine. The higher level of total IgE was found in less than half of the patients and it did not correlate with the severity of eosinophilic infiltration. It was shown that the severity of eosinophilic infiltration correlated with exacerbation of clinical symptoms, endoscopic image, and the presence of inflammatory bowel disease. The higher level of antibodies of ASCA and ANCA was found in approximately 20% of the children with isolated eosinophilic colitis and 63% of children with Crohn's disease.

CONCLUSIONS

The higher concentration of total IgE in less than half of the patients with eosinophilic colitis indicates the need for improving allergy diagnosis also in terms of IgE-independent allergy. The presence of higher levels of antibodies of ASCA and ANCA in some of the patients with isolated eosinophilic colitis indicates the need for further observation for the occurrence of inflammatory bowel disease.

Cardiopulmonary and Gastrointestinal Manifestations of Eosinophil- associated Diseases and Idiopathic Hypereosinophilic Syndromes: Multimodality Imaging Approach

Eosinophil-associated diseases (EADs) are a diverse group of disorders characterized by an increase in circulating or tissue eosinophils. Cardiopulmonary and gastrointestinal system involvement can be due to primary EAD with no known cause or can be secondary to known systemic disease. The cardiopulmonary spectrum of EADs comprises simple pulmonary eosinophilia, acute eosinophilic pneumonia, chronic eosinophilic pneumonia, Churg-Strauss syndrome, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis, parasitic infections, and idiopathic hypereosinophilic syndrome. Eosinophilic gastrointestinal disorders include eosinophilic esophagitis, eosinophilic gastroenteritis, and eosinophilic colitis. Diagnosis is often challenging and requires a combination of clinical and imaging features along with laboratory findings. The absolute eosinophil count in peripheral blood and the percentage of eosinophils in bronchoalveolar lavage fluid are crucial in evaluation of various eosinophilic lung diseases. Although chest radiography is the initial imaging modality used in suspected cases of pulmonary EAD, multidetector computed tomography may demonstrate more characteristic pulmonary patterns, nodules, and subtle parenchymal abnormalities. Barium esophagography is used to assess mucosal abnormalities and the length and diameter of esophageal strictures. Magnetic resonance imaging is superior in providing valuable information in select patients, especially in evaluation of cardiac and gastrointestinal system involvement. Many patients require a multimodality imaging approach to enable diagnosis, guide treatment, and assess treatment response. Knowledge of the clinical features and imaging findings of the spectrum of EADs involving the lungs, heart, and gastrointestinal tract permits optimal patient care.

Downregulation of mouse CCR3 by lentiviral shRNA inhibits proliferation and induces apoptosis of mouse eosinophils

RNA interference has been considered as an effective gene silencing method in basic and preclinical investigations. The aims of the present study were to construct a lentiviral vector expressing a short hairpin RNA (shRNA) targeting the murine CC chemokine receptor 3 (mCCR3), and to investigate its effects on the proliferation and apoptosis of mouse eosinophils. A recombinant lentiviral vector expressing four fragments of mouse CCR3 shRNA (pLVX-mCCR3-1+2+3+4-shRNA) was constructed using subcloning techniques. This novel lentivirus was then packaged into 293T cells by co-transduction with plasmids, including Baculo p35, pCMV R8.2 and VSV. The interference effects of the vector were verified using polymerase chain reaction (PCR) and western blot analyses. The effects of the interference on the proliferation and apoptosis of mouse eosinophils were investigated using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium and terminal deoxynucleotidyl transferase dUTP nick end labeling methods, respectively. The results of the PCR and western blot analyses confirmed that the novel recombinant vector, pLVX-mCCR3-1+2+3+4-shRNA, had high efficiency in inhibiting the mRNA and protein expression levels of mCCR3 in mouse eosinophils. The downregulation of mCCR3 significantly inhibited proliferation of the eosinophils. Furthermore, the present study found that the downregulation of mCCR3 significantly promoted apoptosis of the eosinophils. Therefore, the downregulation of mCCR3 led to the inhibition of proliferation and induction of apoptosis in mouse eosinophils. The predominant characteristics of allergic rhinitis are eosinophil infiltration and release of inflammatory mediators, which appear in a variety of clinical manifestations. The results of the present study indicate that mCCR3 silencing may serve as a putative approach for the treatment of allergic rhinitis.

Colitis as the Sole Initial Presentation of Chronic Granulomatous Disease: Histopathologic Clues to Diagnosis

Chronic granulomatous disease is a rare, inherited immunodeficiency disorder that reduces the superoxide generation ability of phagocytes, leading to recurrent infections and granulomatous inflammation. We report the case of a previously healthy 3-year-old boy who presented with classic features of Crohn disease. Suspicion from histopathologiclogic assessment allowed early diagnosis and treatment for chronic granulomatous disease before the onset of infections.

Chronic eosinophilic leukemia, NOS with t(5;12)(q31;p13)/ETV6-ACSL6 gene fusion: a novel variant of myeloid proliferative neoplasm with eosinophilia

The 2008 World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues introduced a category for myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1. Many of these patients are responsive to tyrosine kinase inhibitor (TKI) therapy. In this case report , we report a unique case of chronic eosinophlic leukemia with novel t(5;12) (q23-31;p13)/ETV6-ACSL6 gene fusion, in which patient was resistant to TKI therapy. This important finding is a novel addition to the above entity in WHO 2008 classification. The ACSL6 gene encodes a long-chain acyl-CoA synthetase, an enzyme that plays an essential role in lipid metabolism and ATP generation pathways in cells. The EBV6-ACSL6 rearrangement is present in diverse types of hematopoietic malignancies. As yet, it is not clear how ACSL6, a gene involved in fatty acid synthesis, contributes to clonal expansion of myeloid progenitor cells. Therefore, elucidating the contribution of ACSL6 to leukemogenesis may allow the development of novel treatment for those resistant to TKI therapy.

Reslizumab in the management of poorly controlled asthma: the data so far

Interleukin-5, an important cytokine in the pathophysiology of asthma, participates in terminal maturation and increases chemotaxis, endothelial adhesion, and activation of eosinophils. Blockade of interleukin-5 activity with monoclonal antibodies have been successful in decreasing eosinophil counts. Reslizumab, a monoclonal antibody that targets interleukin-5, has been studied for the treatment of severe asthma. Several studies have shown that reslizumab can effectively treat severe asthma with an eosinophilic phenotype. Compared to placebo, patients treated with reslizumab had a reduction in the rates of asthma exacerbations and experienced improvement in FEV₁ and asthma control questionnaires scores as early as 4 weeks after the therapy was initiated. Reslizumab was not effective in various asthma outcomes in patients without eosinophilia. The adverse events reported were similar in both treatment and placebo groups. Patients should be observed immediately after treatment because anaphylaxis may occur rarely (0.3%) after exposure to reslizumab. Future surveillance studies are still needed to establish the risks of malignancy and safety during pregnancy.

What are the characteristics of asthma patients with elevated serum IgG4 levels?

INTRODUCTION

IgG4 has recently been a subject of great interest in human pathology. No data are available about the characteristics of asthma patients with elevated IgG4 levels.

POPULATION AND METHODS

An observational study was conducted from January 2006 to March 2015 in a difficult-to-treat population of asthma patients. Twenty-six difficult-to-treat asthma patients with elevated serum IgG4 levels (IgG4/IgG ratio up to 10%) were compared with a control population of 98 difficult-to-treat asthma patients with normal serum IgG4. Blood eosinophilia, total IgE and FeNO were compared between groups to better characterize asthma patients with elevated serum IgG4 levels.

RESULTS

Median IgG4 concentrations were 1.72 g/l [1.19-2.36] and 0.22 g/l [0.10-0.49] in the elevated IgG4 group and normal Ig4 group, respectively. Median blood eosinophilia was more than three times higher in patients with elevated serum IgG4 levels than in controls (0.75 10(9)/L [IQR 0.54-1.78] vs 0.22 10(9)/L [IQR 0.09-0.54] respectively, p < 0.0001). Total IgE was twice as high (264.5 kUI/l [IQR 166.3-779] vs 126 kUI/l [IQR 26-350] respectively; p < 0.05) and FeNO was nearly twice as high (61 [IQR 41-111] ppb vs 35 [IQR 23-51] ppb, p < 0.001). Allergic broncho-pulmonary aspergillosis (ABPA) and eosinophilic granulomatosis with polyangiitis (EGPA) were observed in the asthma patients with elevated serum IgG4. Ten patients had unexplained increased blood eosinophilia.

CONCLUSION

Asthma patients with elevated IgG4 levels have significantly higher blood eosinophilia, total IgE and FeNO. ABPA and EGPA are observed in patients with elevated serum IgG4.

Effect of polyflux membranes on the improvement of hemodialysis-associated eosinophilia: a case series

Hemodialysis-associated eosinophilia (HAE) is believed to be associated with allergic reactions to dialyzer materials. This study aimed to investigate the use of Polyflux membranes to improve HAE. Thirty-one patients suffering from HAE were included. Patients were dialyzed with polysulfone membranes when they developed HAE. After that, patients were dialyzed with Polyflux membranes three times every week, 4 h every time without changing the dialysis parameters and medication. Levels of peripheral eosinophils, hsCRP, IgE, C3a, IL-5 and peripheral CD4+ lymphocytes and CD8+ lymphocytes were assessed before Polyflux treatment, and at 4th, 8th and 12th weeks of treatment. Any symptoms including chest tightness and skin itching were observed during the study period. After 12 weeks of Polyflux membrane dialysis and compared with polysulfone membrane dialysis, levels of peripheral eosinophils were significantly decreased (1.26 ± 0.61 vs. 0.71 ± 0.29 × 10(9)/L, p < 0.001); serum IL-5 levels were significantly decreased (24.43 ± 10.21 vs. 9.11 ± 4.21 pg/mL, p < 0.001); and chest tightness and skin itching were significantly improved (45.2% vs. 19.4%, p = 0.028). After 12 weeks, there was no significant change in serum levels of hsCRP (2.00 ± 0.94 vs. 1.81 ± 0.79 mg/L, p = 0.352), IgE (104.61 ± 98.79 vs. 114.95 ± 101.07 IU/mL, p = 0.422) and C3a (121.61 ± 34.04 vs. 120.29 ± 32.81 µg/L, p = 0.316), and in peripheral levels of CD4+ (589 ± 181 vs. 569 ± 171 cells/mm(3), p = 0.672) and CD8+ (443 ± 123 vs. 414 ± 140 cells/mm(3), p = 0.395) cells. Eosinophil count was correlated with serum IL-5 levels (r = 0.873, p < 0.001). Changing to a Polyflux membrane may alleviate HAE and reduce serum IL-5 levels. Therefore, this could be a strategy to manage HAE in the clinical practice.

Role and Significance of Markers of Inflammation in the Asthmatic Disease

BACKGROUND

Asthma is characterized by airway inflammation which can be reversible.

AIM

Investigation the importance of eosinophils, ECP and IL-5 in asthmatics versus patients with obstructive bronchitis and healthy subjects. We investigated the values before and after the treatment in asthmatics.

MATERIAL AND METHODS

We studied 77 subjects divided in three groups as follows: 1) asthma patients; 2) patients with obstructive bronchitis and 3) control group of healthy subjects. In all the subjects there were determined: Total number of eosinophils (Eo), eosinophilic cationic protein (ECP), Interleukin 5 (IL-5) and allergy tests.

RESULTS

The total number of eosinophils was significantly increased in the group of asthma patients versus second and third group. We found that the presence of ECP demonstrate an ongoing inflammation, with or without clinical symptoms of asthma patients. There was significant difference between the values of ECP of asthma patients versus second and third group. Our results have shown that IL-5 was significantly increased versus second group and controls (p < 0.01). We also found the decrease of the values of inflammatory markers after the treatment with corticosteroids.

CONCLUSIONS

Eosinophils, ECP and IL-5 could be useful markers for selecting allergic patients and could be the monitors of treatment effects.

Eosinophilic Lung Disease: Accompanied with 12 Cases

OBJECTIVES

Eosinophilic lung diseases are a rare group of heterogeneous diseases characterized by the increase of the eosinophil ratio in airways and lung parenchyma. In our clinic, patients diagnosed with eosinophilic lung disease were evaluated with their clinical features and prognoses.

MATERIAL AND METHODS

In our clinic, 12 cases that were diagnosed and followed up for eosinophilic lung disease [eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss syndrome) (n=4), chronic eosinophilic pneumonia (CEP) (n=7), and simple pulmonary eosinophilia (Löffler's syndrome) (n=1)] were retrospectively evaluated.

RESULTS

Of the 12 cases, 8 were females, and the average age was 43 (28-72) years. All cases were undergoing bronchodilator therapy with asthma diagnosis (2 months-40 years). Additionally, 4 of the cases had sinusitis, and 1 had allergic rhinitis. The most common complaints of the patients were difficulty in breathing and coughing, and the duration of complaints was a median of 2 months. Peripheral eosinophilia and total IgE elevation were present during the admission of all cases; additionally, leucocyte elevation was recorded in 10 of them, anemia in 4 of them, and thrombocytosis in 4 of them. Moreover, 43% of the recorded DLCO values were lower than normal. Of the 10 cases that underwent bronchoalveolar lavage (BAL), the eosinophil ratio was above 25% in 7 subjects. Of the 8 cases that underwent transbronchial biopsy, eosinophil-involving infiltration was detected in 6 subjects. Additional findings in cases diagnosed with EGPA were nasal polyposis (n=1), sinusitis (n=2), polyneuropathy (n=1), cardiac involvement (n=2), and skin involvement in biopsy (n=1). Spontaneous recovery was observed in the patient diagnosed with simple pulmonary eosinophilia during the follow-up that was performed based on the history and laboratory and BAL results of the patient. Prednisolone treatment was started for all cases, except for simple pulmonary eosinophilia, and their controls were performed. Relapse was observed in eight cases (EGPA: 4, CEP: 4); during the relapse treatment of one case diagnosed with EGPA, exitus occurred. One case rejected treatment despite the presence of peripheral eosinophilia, and the other cases are being followed-up without medication.

CONCLUSION

Given that the clinical pictures in pulmonary eosinophilia syndromes are on a wide spectrum, a specific diagnosis is important. Progression may differ in each patient, and a close follow-up is necessary during and after the treatment.

Aedes aegypti salivary gland extract ameliorates experimental inflammatory bowel disease

Current therapies for inflammatory bowel disease (IBD) are not totally effective, resulting in persistent and recurrent disease for many patients. Mosquito saliva contains immunomodulatory molecules and therein could represent a novel therapy for IBD. Here, we demonstrated the therapeutic activity of salivary gland extract (SGE) of Aedes aegypti on dextran sulfate sodium (DSS)-induced colitis. For this purpose, C57BL/6 male mice were exposed to 3% DSS in drinking water and treated with SGE at early (days 3-5) or late (days 5-8) time points, followed by euthanasia on days 6 and 9, respectively, for sample collection. The results showed an improvement in clinical disease outcome and postmortem scores after SGE treatment, accompanied by the systemic reduction in peripheral blood lymphocytes, with no impact on bone marrow and mesenteric lymph nodes cellularity or macrophages toxicity. Moreover, a local diminishment of IFN-γ, TNF-α, IL-1β and IL-5 cytokines together with a reduction in the inflammatory area were observed in the colon of SGE-treated mice. Strikingly, early treatment with SGE led to mice protection from a late DSS re-challenging, as observed by decreased clinical and postmortem scores, besides reduced circulating lymphocytes, indicating that the mosquito saliva may present components able to prevent disease relapse. Indeed, high performance liquid chromatography (HPLC) experiments pointed to a major SGE pool fraction (F3) able to ameliorate disease signs. In conclusion, SGE and its components might represent a source of important immunomodulatory molecules with promising therapeutic activity for IBD.

Strongyloidiasis: the cause of multiple gastrointestinal ulcers in an immunocompetent individual

Strongyloidiasis is a common parasitic disease in tropical regions of the world. Infection with Strongyloides stercoralis usually remains asymptomatic with peripheral eosinophilia and uncontrolled growth. Consequently, immunocompromised individuals are at a higher risk of complications of this disease. We present a case of an immunocompetent patient whose complaint of acute abdominal pain was found to be due to gastric and duodenal ulcerations. Laboratory examination revealed significantly elevated absolute eosinophil count at 11,466/mm(3) (normal 0-700/mm(3)). The duodenal biopsy revealed parasitic ova and adult worms suggestive of Strongyloides stercoralis nematode with increased eosinophils in the tissue. We report the first case of multiple gastric and duodenal ulcerations due to Strongyloides stercoralis in an immunocompetent patient. We suggest that the elevated eosinophil count played a central role in the pathogenesis.

Eosinophilic esophagitis: an immune-mediated esophageal disease

Eosinophilic esophagitis (EoE) is an emerging disease defined by esophageal dysfunction, by typical endoscopic findings and by abnormal eosinophilic inflammation within the esophagus. Eosinophilic accumulation in the esophagus occurs as a result of esophageal overexpression of pro-inflammatory mediators, including T cells and mast cells, cytokines such as interleukin (IL)-13, IL-5 and IL-15, as well as chemoattractants (eotaxin and transforming growth factor-β1, fibroblast growth factor and the newly characterized gene--thymic stromal lymphopoietin, which is a key regulator of allergic sensitization initiation). The role of allergy, particularly food allergy in EoE is indisputable, as elimination diet is a proven commonly used treatment for the disease. However, unlike classical immediate IgE-mediated reaction to allergen, EoE is associated with an altered immune response, characterized by a combination of IgE-mediated and non-IgE-mediated mechanisms. In this review, we aim to discuss the many typical aspects of EoE as opposed to other entities involving the esophagus, with focusing on the aberrant immune-mediated key players contributing to the pathogenesis of this unique disease.

Host impairments in patients with neoplastic diseases

Healthy individuals possess an immune system comprising physical barriers, innate and acquired immunity as well as the indigenous microflora that populate the body surfaces. The immune system maintains constant vigilance over the body at the cellular level as well as at the interface between the host integument and the resident microflora. However, neoplastic diseases and their treatment often lead to impaired immunity resulting in an increased risk of infections due to viruses, bacteria, fungi, and protozoa. This chapter explores the various aspects of host impairment focusing on the components of immunity and the interplay between them to explain why it is that these patients succumb to infections per se. In so doing, we hope that the reader will be better equipped to understand the risks patients face so as to anticipate potential infectious complications and implement appropriate measures to help attain successful remission of the neoplastic diseases and maintain the best quality of life for the patient.

Antimicrobial activity of human eosinophil granule proteins

Eosinophils secrete a number of proinflammatory mediators, like cytokines, chemokines, and granule proteins which are responsible for the initiation and sustenance of inflammatory response caused by them. The eosinophil granule proteins, ECP, EDN, MBP, and EPO possess antimicrobial activity against bacteria, helminths, protozoa, and viruses. In this chapter, we describe various assays used to detect and quantitate the antimicrobial activities of eosinophil granule proteins, particularly ECP and EDN. We have taken a model organism for each assay and described the method for antiviral, antihelminthic, antiprotozoan, and antibacterial activity of purified eosinophil granule proteins.

Evaluation of an intragastric challenge model for Shigella dysenteriae 1 in rhesus monkeys (Macaca mulatta) for the pre-clinical assessment of Shigella vaccine formulations

Shigellosis is a worldwide disease, characterized by abdominal pain, fever, vomiting, and the passage of blood- and mucus-streaked stools. Rhesus monkeys and other primates are the only animals that are naturally susceptible to shigellosis. A suitable animal model is required for the pre-clinical evaluation of vaccines candidates. In this study, the minimal dose of Shigella dysenteriae1 1617 strain required to produce dysentery in four of five (80% attack rate) monkeys using an escalating dose range for three groups [2 × 10⁸, 2 × 10⁹ and 2 × 10¹⁰ colony forming unit (CFU)] was determined. In addition, the monkeys were re-infected. The identified optimal challenge dose was 2 × 10⁹ CFU; this dose elicited 60% protection in monkeys when they were re-challenged with a one log higher dose (2 × 10¹⁰ CFU). The challenge dose, 2 × 10¹⁰ CFU, produced severe dysentery in all monkeys, with one monkey dying within 24 h, elicited 100% protection when re-challenged with the same dose. All monkeys exhibited immune responses. This study concludes that the rhesus monkey model closely mimics the disease and immune response seen in humans and is a suitable animal model for the pre-clinical evaluation of Shigella vaccine candidates. Prior infection with the 1617 strain can protect monkeys against subsequent re-challenges with homologous strains.

Neutrophil Inhibitory Factor Selectively Inhibits the Endothelium-Driven Transmigration of Eosinophils In Vitro and Airway Eosinophilia in OVA-Induced Allergic Lung Inflammation

Leukocyte adhesion molecules are involved in cell recruitment in an allergic airway response and therefore provide a target for pharmaceutical intervention. Neutrophil inhibitory factor (NIF), derived from canine hookworm (Ancylostoma caninum), binds selectively and competes with the A-domain of CD11b for binding to ICAM-1. The effect of recombinant NIF was investigated. Intranasal administration of rNIF reduced pulmonary eosinophilic infiltration, goblet cell hyperplasia, and Th₂ cytokine production in OVA-sensitized mice. In vitro, transendothelial migration of human blood eosinophils across IL-4-activated umbilical vein endothelial cell (HUVEC) monolayers was inhibited by rNIF (IC₅₀: 4.6 ± 2.6 nM; mean ± SEM), but not across TNF or IL-1-activated HUVEC monolayers. Treatment of eosinophils with rNIF together with mAb 60.1 directed against CD11b or mAb 107 directed against the metal ion-dependent adhesion site (MIDAS) of the CD11b A-domain resulted in no further inhibition of transendothelial migration suggesting shared functional epitopes. In contrast, rNIF increased the inhibitory effect of blocking mAbs against CD18, CD11a, and VLA-4. Together, we show that rNIF, a selective antagonist of the A-domain of CD11b, has a prominent inhibitory effect on eosinophil transendothelial migration in vitro, which is congruent to the in vivo inhibition of OVA-induced allergic lung inflammation.

Serum interleukin--4 and tumor necrosis factor alpha concentrations in children with primary acid gastroesophageal reflux and acid gastroesophageal reflux secondary to cow's milk allergy

AIM

The possible role of serum interleukin 4 (IL-4) and tumor necrosis factor alpha (TNF- α) in pathogenesis of the reflux symptoms in children with primary acid gastroesophageal reflux (GER) and acid GER secondary to cow's milk allergy (CMA).

MATERIAL AND METHODS

Out of 264 children, 76 (28.8%) patients with primary GER and 62 (23.5%) patients with GER secondary to CMA (pH - monitoring) serum IL-4 and TNF- α concentrations were assessed before treatment, 1 and 2 years after the initiation of the periodically administered pharmacotherapy.

RESULTS

Children with primary GER had mean IL-4 concentrations 0.17 ± 0.06 pg/ml before treatment, 0.08 ± 0.07 pg/ ml after 1-year and 0.07 ± 0.06 pg/ml after 2-years of treatment. The mean IL-4 concentrations were 1.07 ± 0.24, 0.5 ± 0.22 and 0.44 ± 0.19 pg/ml respectively in children with GER secondary to CMA. The mean serum TNF- α concentrations was 3.62 ± 1.30 pg/ml before treatment , 2.16 ± 1,35 pg/ ml after 1 year and 1.65 ± 1.16 pg/ml after 2 years of treatment in children with primary GER. In group with GER secondary to CMA mean serum TNF- α concentrations were 4.95 ± 1.88, 2.53 ± 0.80 and 2.02 ± 0.78 pg/ml respectively. Statistical analysis of the concentration of both cytokines showed their differentiation between them and in the study groups.

CONCLUSIONS

The highest mean serum IL-4 and TNF-α concentrations were observed in children with GER secondary to CMA and in children in control group (with cow's milk allergy and/or other food allergy diagnosed - CMA/FA) before the treatment administration.

Case of eosinophilic cystitis treated with suplatast tosilate as maintenance therapy

Eosinophilic cystitis is a rare inflammatory lesion of the bladder, characterized by massive eosinophilic infiltration of the bladder wall. Its cause is not known definitely. A 49-year-old man consulted our department with a miction pain, gross hematuria, and frequent micturition. Urinalysis showed combined hematuria and pyuria, but urine culture was sterile. Abnormal findings of laboratory examination included an elevated white blood cell (WBC) count (15,700/μL) and the proportion of eosinophils in the peripheral blood was 12% of the WBCs (normal 0–5%). Cystoscopy revealed a solid mass with severe edematous mucosa. Magnetic resonance imaging (MRI) also indicated marked bladder wall thickening, which was suspected for invasive bladder cancer. Transurethral biopsy of the bladder mass was performed with pathological examination revealing features of eosinophilic cystitis. After administration of a combination of prednisolone and suplatast tosilate, followed by monotherapy with suplatast tosilate, regression of the bladder mass, and normalization of the count of peripheral eosinophils were achieved. Fourteen months after steroid therapy, under treatment with suplatast tosilate, there was no relapse of urinary symptoms and the bladder mass.

Innate immune cells in liver inflammation

Innate immune system is the first line of defence against invading pathogens that is critical for the overall survival of the host. Human liver is characterised by a dual blood supply, with 80% of blood entering through the portal vein carrying nutrients and bacterial endotoxin from the gastrointestinal tract. The liver is thus constantly exposed to antigenic loads. Therefore, pathogenic microorganism must be efficiently eliminated whilst harmless antigens derived from the gastrointestinal tract need to be tolerized in the liver. In order to achieve this, the liver innate immune system is equipped with multiple cellular components; monocytes, macrophages, granulocytes, natural killer cells, and dendritic cells which coordinate to exert tolerogenic environment at the same time detect, respond, and eliminate invading pathogens, infected or transformed self to mount immunity. This paper will discuss the innate immune cells that take part in human liver inflammation, and their roles in both resolution of inflammation and tissue repair.

ETV6 fusion genes in hematological malignancies: a review

Translocations involving band 12p13 are one of the most commonly observed chromosomal abnormalities in human leukemia and myelodysplastic syndrome. Their frequently result in rearrangements of the ETV6 gene. At present, 48 chromosomal bands have been identified to be involved in ETV6 translocations, insertions or inversions and 30 ETV6 partner genes have been molecularly characterized. The ETV6 protein contains two major domains, the HLH (helix-loop-helix) domain, encoded by exons 3 and 4, and the ETS domain, encoded by exons 6 through 8, with in between the internal domain encoded by exon 5. ETV6 is a strong transcriptional repressor, acting through its HLH and internal domains. Five potential mechanisms of ETV6-mediated leukemogenesis have been identified: constitutive activation of the kinase activity of the partner protein, modification of the original functions of a transcription factor, loss of function of the fusion gene, affecting ETV6 and the partner gene, activation of a proto-oncogene in the vicinity of a chromosomal translocation and dominant negative effect of the fusion protein over transcriptional repression mediated by wild-type ETV6. It is likely that ETV6 is frequently involved in leukemogenesis because of the large number of partners with which it can rearrange and the several pathogenic mechanisms by which it can lead to cell transformation.