The role of eosinophils and basophils in allergic diseases considering genetic findings

Measurement of Anions in Tear Fluid Using Ion Chromatography

PURPOSE

Tear fluid (TF) contains a variety of electrolytes that exhibit a strong correlation with its osmotic pressure. These electrolytes are also related to the etiology of diseases on ocular surfaces such as dry eye syndromes and keratopathy. Although positive ions (cations) in TF have been investigated to understand their roles, negative ions (anions) have hardly been studied because applicable analytical methods are restricted to a few kinds. In this study, we established a method to analyze the anions involved in a sufficiently small amount of TF for in situ diagnosis of a single subject.

METHODS

Twenty healthy volunteers (10 men and 10 women) were recruited. Anions in their TF were measured on a commercial ion chromatograph (IC-2010, Tosoh, Japan). Tear fluid (5 μL or more) was collected from each subject with a glass capillary, diluted with 300 μL of pure water, and conveyed to the chromatograph. We successfully monitored the concentrations of bromide, nitrate, phosphate, and sulfate anions (Br - , NO 3- , HPO 42- , and SO 42- , respectively) in TF.

RESULTS

Br - and SO 42- were universally detected in all samples, whereas NO 3- was found in 35.0% and HPO 42- in 30.0% of them. The mean concentrations (mg/L) of each anion were Br - , 4.69 ± 0.96; NO 3- , 0.80 ± 0.68; HPO 42- , 17.48 ± 7.60; and SO 42- , 3.34 ± 2.54. As for SO 42- , no sex differences or diurnal variations were observed.

CONCLUSIONS

We established an efficient protocol to quantitate various inorganic anions involved in a small amount of TF using a commercially available instrument. This is the first step to elucidate the role of anions in TF.

RNA Sequencing and Bioinformatics Analysis to Reveal Potential Biomarkers in Patients with Combined Allergic Rhinitis and Asthma Syndrome

Introduction

Combined allergic rhinitis and asthma syndrome (CARAS) is a concurrent clinical or subclinical allergic symptom of diseases of the upper and lower respiratory tract. This study is the first to explore the expression profiles of mRNA, lncRNA, and circRNA in CARAS using RNA sequencing, which may provide insight into the mechanisms underlying CARAS.

Material and Methods

Whole blood samples from nine participants (three CARAS patients, three AR patients, and three normal control participants) were subjected to perform RNA sequencing, followed by identification of differentially expressed lncRNAs (DElncRNAs), circRNAs (DEcircRNAs) and mRNAs (DEmRNAs). Then, lncRNA/circRNA-mRNA regulatory pairs were constructed, followed by functional analysis, immune infiltration analysis, drug prediction, and expression validation with RT-qPCR and ELISA.

Results

The results showed that 61 DEmRNAs, 23 DElncRNAs and 3 DEcircRNAs may be related to the occurrence and development of CARAS. KRT8 may be implicated in the development of AR into CARAS. Three immunity-related mRNAs (IDO1, CYSLTR2, and TEC) and two hypoxia-related mRNAs (TKTL1 and VLDLR) were associated with the occurrence and development of CARAS. TEC may be considered a drug target for Dasatinib in treating CARAS. Several lncRNA/circRNA-mRNA regulatory pairs were identified in CARAS, including LINC00452/MIR4280HG/hsa_circ_0007272/hsa_circ_0070934-CLC, HEATR6-DT/LINC00639/LINC01783/hsa_circ_0008903-TEC, RP11-71L14.3-IDO1/SMPD3, RP11-178F10.2-IDO1/HRH4, and hsa_circ_0008903-CYSLTR2, which may indicate potential regulatory effects of lncRNAs/circRNAs in CARAS. Dysregulated levels of immune cell infiltration may be closely related to CARAS.

Conclusion

The regulating effect of lncRNA/circRNA-immunity/hypoxia-related mRNA regulatory pairs may be involved in the occurrence and development of CARAS.

Leptin favors imbalance of antigen-specific CD4+ T-cells associated with severity of cat allergy

Introduction

Obesity can complicate IgE-mediated allergic diseases. In the present study, we aimed to investigate the ability of obesity-related concentrations of leptin to modulate the in vitro effector and regulatory Fel d1-specific CD4+ T-cell subsets in patients allergic to cat, considered the third most common cause of respiratory allergy in humans.

Methods

For this study, plasma and peripheral blood mononuclear cells (PBMC) from 30 cat-allergic patients with mild, moderate and severe respiratory symptoms were obtained. The PBMC cultures were stimulated with Fel d1 antigen (10 µg/mL) in the presence or absence of obesity-related leptin dose (50 ηg/mL). After 6 days, the levels of cytokines and IgE in the supernatants were evaluated by multiplex and ELISA, respectively. The frequency of different non-follicular (CXCR5-) and follicular (CXCR5+) Fel d1-specific CD4+ T cell subsets was determined by flow cytometry. The plasma levels of leptin and IgE anti-cat titers were evaluated by ELISA and ImmunoCAP, respectively.

Results and conclusions

Fel d1 induced both IgE production and release of cytokines related to Th2, Th9 and Th17 cell phenotypes. Feld1 was more efficient in increasing the frequency of TFHIL-21- cells positive for IL-4, IL-5 and IL-13 than TFHIL-21+ cell subsets. Leptin favored the expansion Th2-like and Th9-like cells and TFHIL-21- cells positive for IL-4, IL-5 and IL-13, but reduced the proportion of conventional (Treg/Tr-1) and follicular (TFR) regulatory CD4+ T-cell subsets expressing or not CD39 marker. Finally, many of the imbalances between Fel d1-specific CD4+ T-cells were also correlated with plasma leptin and anti-Fel d1 IgE titers. In summary, hyperleptinemia should negatively impact on the severity of cat allergies by favoring the expansion of pathogenic Fel d1-specific CD4+ T-cell phenotypes and damaging the functional status of regulatory CD4+ T-cell subsets.

Blood hematology and biochemical of four laying hen strains exposed to acute heat stress

This study is aimed at defining physiological responses to heat stress (HS) in four different lines to better understand the underlying mechanisms of various responses in these genotypes when exposed to heat for a short period. At the age of 30 weeks, 176 laying hens (44 each from the Fayoumi, Golden Sabahia, White Leghorn, and Lohman Brown) were allotted to 2 groups (thermoneutral temperature (26.0 ± 1 °C) and HS (35 ± 1 °C) with relative humidity 55 ± 5% for 6 h/day). Blood samples were collected after 6 h of heat. According to the findings of this study, acute HS increased the concentration of LH in hens by 20.2% while decreasing the concentration of FSH by 4.24. Genotype was found to have a significant effect on blood hematology and most blood biochemical. Significant differences were found between heat stress and genotype in most of the blood parameters. Golden sabahia laying hens had significantly higher WBC, IgY, and LH levels than other groups under HS. The findings of the current study suggested that Lohman Brown was less tolerant to acute HS than another genotype.

Dynamic changes in blood immune cell composition and function in Holstein and Jersey steers in response to heat stress

Heat stress has detrimental effects on livestock via diverse immune and physiological changes; heat-stressed animals are rendered susceptible to diverse diseases. However, there is relatively little information available regarding the altered immune responses of domestic animals in heat stress environments, particularly in cattle steers. This study aimed to determine the changes in the immune responses of Holstein and Jersey steers under heat stress. We assessed blood immune cells and their functions in the steers of two breeds under normal and heat stress conditions and found that immune cell proportions and functions were altered in response to different environmental conditions. Heat stress notably reduced the proportions of CD21+MHCII+ B cell populations in both breeds. We also observed breed-specific differences. Under heat stress, in Holstein steers, the expression of myeloperoxidase was reduced in the polymorphonuclear cells, whereas heat stress reduced the WC1+ γδ T cell populations in Jersey steers. Breed-specific changes were also detected based on gene expression. In response to heat stress, the expression of IL-10 and IL-17A increased in Holstein steers alone, whereas that of IL-6 increased in Jersey steers. Moreover, the mRNA expression pattern of heat shock protein genes such as Hsp70 and Hsp90 was significantly increased in only Holstein steers. Collectively, these results indicate that altered blood immunological profiles may provide a potential explanation for the enhanced susceptibility of heat-stressed steers to disease. The findings of this study provide important information that will contribute to developing new strategies to alleviate the detrimental effects of heat stress on steers.

Premature birth, low birth weight, small for gestational age and chronic non-communicable diseases in adult life: A systematic review with meta-analysis

BACKGROUND

Individuals who were born prematurely (PT), with low birth weight (LBW), or small for gestational age (SGA) appear to present a set of permanent changes that make them more susceptible to develop chronic non-communicable diseases (CNCD) in adult life.

AIM

Investigating the association between PT birth, LBW or SGA at birth and CNCD incidence in adult life.

METHODS

Systematic review with meta-analysis of studies available in three databases - two of them are official (PubMed and Web of Science) and one is gray literature (OpenGrey) - based on pre-established search and eligibility criteria.

RESULTS

Sixty-four studies were included in the review, 93.7% of them only investigated one of the exposure variables (46.7% LBW, 35.0% PT and 18.3% SGA at birth), whereas 6.3% investigated more than one exposure variable (50.0% LBW and PT; 50.0% SGA and PT). There was association among all exposure variables in the following outcomes: cardiometabolic (CMD) and glycidic metabolism (GMD) disorders, changes in body composition and risk of developing metabolic syndrome (MS). Female sex was identified as risk factor in the exposure-outcome association. Eighteen (18) articles were included in the meta-analysis. There was positive association between LBW and incidence of CMD (OR: 1.25 [95%CI: 1.11; 1.41]; 07 studies), GMD (OR: 1.70 [95%CI: 1.25; 2.30]; 03 studies) and MS (OR: 1.75 [95%CI: 1.27; 2.40]; 02 studies) in adult life. PT was positively associated with CMD (OR: 1.38 [95%CI: 1.27; 1.51]; 05 studies).

CONCLUSIONS

LBW and PT are associated with CMD and GMD development, as well as with the risk of developing MS in adult life.

Immune Cell Metabolism in Tumor Microenvironment

Tumor microenvironment (TME) is composed of tumor cells, immune cells, cytokines, extracellular matrix, etc. The immune system and the metabolisms of glucose, lipids, amino acids, and nucleotides are integrated in the tumorigenesis and development. Cancer cells and immune cells show metabolic reprogramming in the TME, which intimately links immune cell functions and edits tumor immunology. Recent findings in immune cell metabolism hold the promising possibilities toward clinical therapeutics for treating cancer. This chapter introduces the updated understandings of metabolic reprogramming of immune cells in the TME and suggests new directions in manipulation of immune responses for cancer diagnosis and therapy.

The association of hemocyte profile and obstructive sleep apnea

BACKGROUND

The hemocyte profile is one of the most frequently requested clinical laboratory tests. However, the analysis of blood cell indexes of obstructive sleep apnea (OSA) patients in previous studies was not comprehensive. And, this study aimed to fully analyze the blood routine in OSA patients.

METHODS

A retrospective study was conducted on 1087 male patients, who were admitted to the sleep center of Nanfang Hospital from May 2013 to February 2018. According to the apnea hypopnea index (AHI), patients were divided into four groups: control group (AHI < 5, n = 135), mild OSA (5 ≦ AHI < 15, n = 185), moderate OSA (15 ≦ AHI < 30, n = 171), and severe OSA (AHI ≧ 30, n = 596). Data collected included sleep parameters, complete blood routine, body mass index (BMI), age, and comorbidities.

RESULTS

In our study, leukocytes, neutrophils, lymphocytes, monocytes, eosinophils, basophils, erythrocytes, hemoglobin, hematocrit, platelets, MPV, and PDW-SD were statistically significant among the four groups based on AHI (P < 0.05), but no significant differences were found in MCV, RDW-SD, N/L, and P/L ratio (P > 0.05). Neutrophils, lymphocytes, monocytes, eosinophils, basophils, hemoglobin, hematocrit, platelets, and MPV were significantly correlated with AHI. Moreover, multiple linear regression analysis demonstrated that hematocrit (β = 73.254, P = 0.001), neutrophils (β = 1.414, P = 0.012), and lymphocytes (β = 4.228, P < 0.001) were independently associated with AHI.

CONCLUSION

Neutrophils, lymphocytes, and hematocrit were independently associated with OSA severity. And combining these three blood cell indicators could contribute to the diagnosis of OSA.

NOx in exhaled breath condensate is related to allergic sensitization in young and middle-aged adults

BACKGROUND

Asthma and allergic diseases are heterogeneous. Measurement of biomarkers in exhaled breath condensate (EBC) may help to discriminate between different phenotypes and may assist with clinical prognostication.

OBJECTIVES

We aimed to assess associations between total nitric oxide products (NO_x ) in EBC and different allergic phenotypes and lung function in young and middle-aged adults.

METHODS

Cross-sectional analyses were nested within two Australian longitudinal studies, the Melbourne Atopy Cohort Study (MACS, mean age 17.8 years) and the Tasmanian Longitudinal Health Study (TAHS, mean age 49.4 years). Levels of EBC NO_x were determined by Griess-reaction fluorescent method. Associations were assessed between EBC NO_x and different allergic phenotypes, lung function and airway reactivity.

RESULTS

Atopy, with or without asthma or rhinitis, was associated with increased EBC NO_x levels particularly in individuals with poly-aero-sensitization. These findings were generally consistent across the two age groups. In the older cohort, use of ICS in the previous 12 months masked the association between sensitization and EBC NO_x (OR = 0.64, 95% CI = 0.21-1.96, p for interaction = 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

In these population-based samples, EBC NO_x was most strongly associated with atopic sensitization, rather than either current asthma or rhinitis, possibly indicating underlying increased airway inflammation associated with atopy. Therefore, EBC NO_x could be a key predictor of atopy in both young and middle-aged adults, regardless of the presence of concomitant asthma or rhinitis.

Orchestration of epithelial-derived cytokines and innate immune cells in allergic airway inflammation

Allergic asthma, a chronic respiratory disease, is a leading worldwide health problem, which inflames and constricts the airways, leading to breathing difficulty. Many studies have focused on the pathogenesis contributed by the adaptive immune system, including CD4+ T lymphocytes in delayed type hypersensitivity and B cell-produced IgE in anaphylaxis. More recently, a focus on the airway mucosal barrier and the innate immune system has highlighted, in coordination with T and B cells, to initiate and establish disease. This review highlights the impacts of epithelial-derived cytokines and innate immune cells on allergic airway reactions.

Unlike Th1/Th17 cells, Th2/Th9 cells selectively migrate to the limbus/conjunctiva and initiate an eosinophilic infiltration process

In this study we compared polarized mouse T-helper (Th) lymphocytes of four populations, sensitized against an ocular antigen, for their patterns of migration and induction of inflammatory processes in recipient mouse eyes expressing the target antigen. Th1, Th2, Th9 and Th17 cells transgenically expressing T-cell receptor (TCR) specific against hen egg lysozyme (HEL) were adoptively transferred to recipient mice expressing HEL in their eyes. Recipient eyes collected 4 or 7 days post injection were analyzed for histopathological changes. Th1 and Th17 cells induced moderate to severe intraocular inflammation in the recipient mouse eyes, but essentially did not migrate into the conjunctiva. In contrast, Th2 and Th9 cells invaded minimally the intraocular space of recipient eyes, but accumulated in the limbus and migrated into the conjunctiva of the recipient mice and initiated allergy-like inflammatory responses, as indicated by remarkable eosinophil involvement. These data thus shed new light on the differences between the migration patterns and ocular pathogenic processes mediated by Th1/Th17 and by Th2/Th9 populations.

Genome-wide association of white blood cell counts in Hispanic/Latino Americans: the Hispanic Community Health Study/Study of Latinos

Circulating white blood cell (WBC) counts (neutrophils, monocytes, lymphocytes, eosinophils, basophils) differ by ethnicity. The genetic factors underlying basal WBC traits in Hispanics/Latinos are unknown. We performed a genome-wide association study of total WBC and differential counts in a large, ethnically diverse US population sample of Hispanics/Latinos ascertained by the Hispanic Community Health Study and Study of Latinos (HCHS/SOL). We demonstrate that several previously known WBC-associated genetic loci (e.g. the African Duffy antigen receptor for chemokines null variant for neutrophil count) are generalizable to WBC traits in Hispanics/Latinos. We identified and replicated common and rare germ-line variants at FLT3 (a gene often somatically mutated in leukemia) associated with monocyte count. The common FLT3 variant rs76428106 has a large allele frequency differential between African and non-African populations. We also identified several novel genetic loci involving or regulating hematopoietic transcription factors (CEBPE-SLC7A7, CEBPA and CRBN-TRNT1) associated with basophil count. The minor allele of the CEBPE variant associated with lower basophil count has been previously associated with Amerindian ancestry and higher risk of acute lymphoblastic leukemia in Hispanics. Together, these data suggest that germline genetic variation affecting transcriptional and signaling pathways that underlie WBC development and lineage specification can contribute to inter-individual as well as ethnic differences in peripheral blood cell counts (normal hematopoiesis) in addition to susceptibility to leukemia (malignant hematopoiesis).

Blunted Autonomic Responses and Low-Grade Inflammation in Mongolian Adults Born at Low Birth Weight

Low birth weight (LBW) has been considered as a risk factor for adult hypertension that is associated with deterioration of autonomic functions and low-grade inflammation. To explore the above effects of LBW, we measured blood pressure (BP) and heart rate variability during postural change from a supine position to a sitting position in 21 healthy Mongolian adults aged 23-34 years: 4 with LBW (birth weight < 2,500 g), 13 with normal birth weight (NBW, 2,500 g ≤ birth weight < 4,000 g), and 4 with high birth weight (HBW, ≥ 4,000 g). Mongolian population is known to have higher prevalence of hypertension. The ratio of low frequency (LF, 0.04-0.15 Hz) to high frequency components (HF, 0.15-0.40 Hz) was used as an index of sympathetic nerve activity, and HF was used as an index of parasympathetic nerve activity. In contrast to the NBW group, the LBW and HBW groups showed no significant increase in heart rate, systolic BP and LF/HF following postural change. We also measured blood cell counts and other blood parameters related to inflammation. After adjusting for age, BMI, sex and family history of hypertension, LBW was retained as an independent predictor only for higher counts of leukocytes (β = -0.51, p < 0.05), basophils (β = -0.62, p < 0.01), eosinophils (β = -0.83, p < 0.001), and platelets (β = -0.61, p < 0.05). We propose that LBW leads to blunted autonomic responses and low-grade inflammation in seemingly healthy Mongolian adults.

Mast cell secretome: Soluble and vesicular components

Mast cells are multifunctional master cells implicated in both innate and adaptive immune responses. Their role has been best characterized in allergy and anaphylaxis; however, emerging evidences support their contribution to a wide variety of human diseases. Mast cells, being capable of both degranulation and subsequent recovery, have recently attracted substantial attention as also being rich sources of secreted extracellular vesicles (including exosomes and microvesicles). Along with secreted de novo synthesized soluble molecules and secreted preformed granules, the membrane-enclosed extracellular vesicles represent a previously unexplored part of the mast cell secretome. In this review article we summarize available data regarding the different soluble molecules and membrane-enclosed structures secreted by mast cells. Furthermore, we provide an overview of the release mechanisms including degranulation, piecemeal degranulation, transgranulation, and secretion of different types of extracellular vesicles. Finally, we aim to give a summary of the known biological functions associated with the different mast cell-derived secretion products. The increasingly recognized complexity of mast cell secretome may provide important novel clues to processes by which mast cells contribute to the development of different pathologies and are capable of orchestrating immune responses both in health and disease.

Comprehensive population-based genome sequencing provides insight into hematopoietic regulatory mechanisms

Genetic variants affecting hematopoiesis can influence commonly measured blood cell traits. To identify factors that affect hematopoiesis, we performed association studies for blood cell traits in the population-based Estonian Biobank using high-coverage whole-genome sequencing (WGS) in 2,284 samples and SNP genotyping in an additional 14,904 samples. Using up to 7,134 samples with available phenotype data, our analyses identified 17 associations across 14 blood cell traits. Integration of WGS-based fine-mapping and complementary epigenomic datasets provided evidence for causal mechanisms at several loci, including at a previously undiscovered basophil count-associated locus near the master hematopoietic transcription factor CEBPA The fine-mapped variant at this basophil count association near CEBPA overlapped an enhancer active in common myeloid progenitors and influenced its activity. In situ perturbation of this enhancer by CRISPR/Cas9 mutagenesis in hematopoietic stem and progenitor cells demonstrated that it is necessary for and specifically regulates CEBPA expression during basophil differentiation. We additionally identified basophil count-associated variation at another more pleiotropic myeloid enhancer near GATA2, highlighting regulatory mechanisms for ordered expression of master hematopoietic regulators during lineage specification. Our study illustrates how population-based genetic studies can provide key insights into poorly understood cell differentiation processes of considerable physiologic relevance.

Decrease of Airway Allergies After Lung Transplantation Is Associated With Reduced Basophils and Eosinophils

BACKGROUND

Allergies are hypersensitive reactions of the immune system on antigen exposure similar to immune reactions after transplantation (Tx). Their activity can change after Tx. The lung as a transplantable organ is challenged two-fold, by antigens from the blood and the air environment. Herein we analyzed if airway allergies change after lung Tx.

METHODS

We systematically reviewed patients' airway allergies before and after lung Tx between 1992 and 2014. The course of lymphocytes, thrombocytes, and leukocytes, among them neutrophils, eosinophils, and basophils, was analyzed in patients in whom airway allergies have changed and in whom they did not change.

RESULTS

From 362 lung transplanted patients, 44 patients had suffered from allergies before Tx (12.2%). In 20 of these patients (45.5%), airway allergies disappeared completely within 1 year after lung Tx and were persistently absent thereafter. In these patients, basophils and eosinophils decreased significantly (P < .0012); in contrast, cells did not decrease in patients whose allergies did not disappear. Leukocytes overall, and in particular, neutrophils, decreased significantly in patients whose allergy disappeared (P < .014, P < .012, respectively).

CONCLUSIONS

Airway allergies disappeared in almost half of cases after lung Tx. Along with this reduction, basophils and eosinophils decreased as potentially responsible cells for this phenomenon. These findings may stimulate intensified research on basophils and eosinophils as major drivers of airway allergies.

Partial pathogen protection by tick-bite sensitization and epitope recognition in peptide-immunized HLA DR3 transgenic mice

Ticks are notorious vectors of disease for humans, and many species of ticks transmit multiple pathogens, sometimes in the same tick bite. Accordingly, a broad-spectrum vaccine that targets vector ticks and pathogen transmission at the tick/host interface, rather than multiple vaccines against every possible tickborne pathogen, could become an important tool for resolving an emerging public health crisis. The concept for such a tick protective vaccine comes from observations of an acquired tick resistance (ATR) that can develop in non-natural hosts of ticks following sensitization to tick salivary components. Mice are commonly used as models to study immune responses to human pathogens but normal mice are natural hosts for many species of ticks and fail to develop ATR. We evaluated HLA DR3 transgenic (tg) "humanized" mice as a potential model of ATR and assessed the possibility of using this animal model for tick protective vaccine discovery studies. Serial tick infestations with pathogen-free Ixodes scapularis ticks were used to tick-bite sensitize HLA DR3 tg mice. Sensitization resulted in a cytokine skew favoring a Th2 bias as well as partial (57%) protection to infection with Lyme disease spirochetes (Borrelia burgdorferi) following infected tick challenge when compared to tick naïve counterparts. I. scapularis salivary gland homogenate (SGH) and a group of immunoinformatic-predicted T cell epitopes identified from the I. scapularis salivary transcriptome were used separately to vaccinate HLA DR3 tg mice, and these mice also were assessed for both pathogen protection and epitope recognition. Reduced pathogen transmission along with a Th2 skew resulted from SGH vaccination, while no significant protection and a possible T regulatory bias was seen in epitope-vaccinated mice. This study provides the first proof-of-concept for using HLA DR tg "humanized" mice for studying the potential tick protective effects of immunoinformatic- or otherwise-derived tick salivary components as tickborne disease vaccines.

Activation states of blood eosinophils in asthma

Asthma is characterized by airway inflammation rich in eosinophils. Airway eosinophilia is associated with exacerbations and has been suggested to play a role in airway remodelling. Recruitment of eosinophils from the circulation requires that blood eosinophils become activated, leading to their arrest on the endothelium and extravasation. Circulating eosinophils can be envisioned as potentially being in different activation states, including non-activated, pre-activated or 'primed', or fully activated. In addition, the circulation can potentially be deficient of pre-activated or activated eosinophils, because such cells have marginated on activated endothelium or extravasated into the tissue. A number of eosinophil surface proteins, including CD69, L-selectin, intercellular adhesion molecule-1 (ICAM-1, CD54), CD44, P-selectin glycoprotein ligand-1 (PSGL-1, CD162), cytokine receptors, Fc receptors, integrins including αM integrin (CD11b), and activated conformations of Fc receptors and integrins, have been proposed to report cell activation. Variation in eosinophil activation states may be associated with asthma activity. Eosinophil surface proteins proposed to be activation markers, with a particular focus on integrins, and evidence for associations between activation states of blood eosinophils and features of asthma are reviewed here. Partial activation of β1 and β2 integrins on blood eosinophils, reported by monoclonal antibodies (mAbs) N29 and KIM-127, is associated with impaired pulmonary function and airway eosinophilia, respectively, in non-severe asthma. The association with lung function does not occur in severe asthma, presumably due to greater eosinophil extravasation, specifically of activated or pre-activated cells, in severe disease.

Lessons learned from mice and man: mimicking human allergy through mouse models

The relevance of using mouse models to represent human allergic pathologies is still unclear. Recent studies suggest the limitations of using models as a standard for assessing immune response and tolerance mechanisms, as mouse models often do not sufficiently depict human atopic conditions. Allergy is a combination of aberrant responses to innocuous environmental agents and the subsequent TH2-mediated inflammatory responses. In this review, we will discuss current paradigms of allergy - specifically, TH2-mediated and IgE-associated immune responses - and current mouse models used to recreate these TH2-mediated pathologies. Our overall goal is to highlight discrepancies that exist between mice and men by examining the advantages and disadvantages of allergic mouse models with respect to the human allergic condition.

MicroRNAs in allergy and asthma

microRNAs (miRNAs) are short, single-stranded RNA molecules that function together with the partner proteins and cause degradation of target mRNAs or inhibit their translation. A particular miRNA can have hundreds of targets; therefore, miRNAs cumulatively influence the expression of a large proportion of genes. The functions of miRNAs in human diseases have been studied since their discovery in mammalian cells approximately 12 years ago. However, the role of miRNAs in allergic disease has only very recently begun to be uncovered. The purpose of this review is to provide an overview of the functions of miRNAs involved in the development of allergic diseases. We describe here the functions of miRNAs that regulate Th2 polarization and influence general inflammatory and tissue responses. In addition, we will highlight findings about the functions of extracellular miRNAs as possible noninvasive biomarkers of diseases with heterogeneous phenotypes and complex mechanisms and briefly discuss advances in the development of miRNA-based therapeutics.