Fine ambient particles from various sites in europe exerted a greater IgE adjuvant effect than coarse ambient particles in a mouse model

Different Phenotypes in Asthma: Clinical Findings and Experimental Animal Models

Asthma is a respiratory allergic disease presenting a high prevalence worldwide, and it is responsible for several complications throughout life, including death. Fortunately, asthma is no longer recognized as a unique manifestation but as a very heterogenic manifestation. Its phenotypes and endotypes are known, respectively, as pathologic and molecular features that might not be directly associated with each other. The increasing number of studies covering this issue has brought significant insights and knowledge that are constantly expanding. In this review, we intended to summarize this new information obtained from clinical studies, which not only allowed for the creation of patient clusters by means of personalized medicine and a deeper molecular evaluation, but also created a connection with data obtained from experimental models, especially murine models. We gathered information regarding sensitization and trigger and emphasizing the most relevant phenotypes and endotypes, such as Th2-^high asthma and Th2-^low asthma, which included smoking and obesity-related asthma and mixed and paucigranulocytic asthma, not only in physiopathology and the clinic but also in how these phenotypes can be determined with relative similarity using murine models. We also further investigated how clinical studies have been treating patients using newly developed drugs focusing on specific biomarkers that are more relevant according to the patient's clinical manifestation of the disease.

All the small things: How virus-like particles and liposomes modulate allergic immune responses

Recent years have seen a dramatic increase in the range of applications of virus‐like nanoparticle (VNP)‐ and liposome‐based antigen delivery systems for the treatment of allergies. These platforms rely on a growing number of inert virus‐backbones or distinct lipid formulations and intend to engage the host's innate and/or adaptive immune system by virtue of their co‐delivered immunogens. Due to their particulate nature, VNP and liposomal preparations are also capable of breaking tolerance against endogenous cytokines, Igs, and their receptors, allowing for the facile induction of anti‐cytokine, anti‐IgE, or anti‐FcεR antibodies in the host. We here discuss the “pros and cons” of inducing such neutralizing autoantibodies. Moreover, we cover another major theme of the last years, i.e., the engineering of non‐anaphylactogenic particles and the elucidation of the parameters relevant for the specific trafficking and processing of such particles in vivo. Finally, we put the various technical advances in VNP‐ and liposome‐research into (pre‐)clinical context by referring and critically discussing the relevant studies performed to treat allergic diseases.

Biological effects of airborne fine particulate matter (PM2.5) exposure on pulmonary immune system

Airborne fine particulate matter (PM_2.5) attracts more and more attention due to its environmental effects. The immune system appears to be a most sensitive target organ for the environmental pollutants. Inhaled PM_2.5 can deposit in different compartments in the respiratory tract and interact with epithelial cells and resident immune cells. Exposed to PM_2.5 can induce local or systematic inflammatory responses. This review focus on the effects of respiratory tract exposed to PM_2.5. Firstly, we introduced the major emission sources, basic characteristics of PM_2.5 and discussed its immunoadjuvant potential. Secondly, we elaborated the immune cells in the respiratory tract and the deposition of PM_2.5 regarding the structural characteristics of the respiratory tract. Furthermore, we summarized the in vivo/vitro studies that revealed the immunotoxic effects of PM_2.5 exposure to pulmonary cellular effectors and explored the contribution of PM_2.5 exposure to the Th1/Th2 balance.

Asthma phenotypes and IgE responses

The discovery of IgE represented a major breakthrough in allergy and asthma research, whereas the clinical interest given to IgE in asthma has been blurred until the arrival of anti-IgE biotherapy. Novel facets of the complex link between IgE and asthma have been highlighted by the effect of this treatment and by basic research. In parallel, asthma phenotyping recently evolved to the concept of endotypes, relying on identified/suspected pathobiological mechanisms to phenotype patients, but has not yet clearly positioned IgE among biomarkers of asthma.In this review, we first summarise recent knowledge about the regulation of IgE production and its main receptor, FcεRI. In addition to allergens acting as classical IgE inducers, viral infections as well as air pollution may trigger the IgE pathway, notably resetting the threshold of IgE sensitivity by regulating FcεRI expression. We then analyse the place of IgE in different asthma endo/phenotypes and discuss the potential interest of IgE among biomarkers in asthma.

Comparative immunology of allergic responses

Allergic responses occur in humans, rodents, non-human primates, avian species, and all of the domestic animals. These responses are mediated by immunoglobulin E (IgE) antibodies that bind to mast cells and cause release/synthesis of potent mediators. Clinical syndromes include naturally occurring asthma in humans and cats; atopic dermatitis in humans, dogs, horses, and several other species; food allergies; and anaphylactic shock. Experimental induction of asthma in mice, rats, monkeys, sheep, and cats has helped to reveal mechanisms of pathogenesis of asthma in humans. All of these species share the ability to develop a rapid and often fatal response to systemic administration of an allergen--anaphylactic shock. Genetic predisposition to development of allergic disease (atopy) has been demonstrated in humans, dogs, and horses. Application of mouse models of IgE-mediated allergic asthma has provided evidence for a role of air pollutants (ozone, diesel exhaust, environmental tobacco smoke) in enhanced sensitization to allergens.

Indoor pollutant exposure is associated with heightened respiratory symptoms in atopic compared to non-atopic individuals with COPD

Background

Indoor particulate matter (PM) has been linked to respiratory symptoms in former smokers with COPD. While subjects with COPD and atopy have also been shown to have more frequent respiratory symptoms, whether they exhibit increased susceptibility to PM as compared to their non-atopic counterparts remains unclear. The aim of this study was to determine whether atopic individuals with COPD have greater susceptibility to PM compared to non-atopic individuals with COPD.

Methods

Former smokers with moderate to severe COPD were enrolled (n = 77). PM_2.5, PM with diameter <2.5 micrometers, was measured in the main living area over three one-week monitoring periods at baseline, 3, and 6 months. Quality of life, respiratory symptoms and medication use were assessed by questionnaires. Serum was analyzed for specific IgE for mouse, cockroach, cat, dog and dust mite allergens. Atopy was established if at least one test was positive. Interaction terms between PM and atopy were tested and generalized estimating equation analysis determined the effect of PM concentrations on health outcomes. Multivariate models were adjusted for age, sex, education, race, season, and baseline lung function and stratified by atopic status.

Results

Among atopic individuals, each 10 μg/m³ increase in PM was associated with higher risk of nocturnal symptoms (OR, 1.95; P = 0.02), frequent wheezing (OR, 2.49; P = 0.02), increased rescue medication use (β = 0.14; P = 0.02), dyspnea (β = 0.23; P < 0.001), higher St. George’s Respiratory Quality of Life score (β = 2.55; P = 0.01), and higher breathlessness, cough, and sputum score (BCSS) (β = 0.44; P = 0.01). There was no association between PM and health outcomes among the non-atopic individuals. Interaction terms between PM_2.5 and atopy were statistically significant for nocturnal symptoms, frequency of rescue medication use, and BCSS (all P < 0.1).

Conclusions

Individuals with COPD and atopy appear to be at higher risk of adverse respiratory health effects of PM exposure compared to non-atopic individuals with COPD.

Particles influence allergic responses in mice--role of gender and particle size

Epidemiological evidence suggesting that exposure to traffic air pollution may enhance sensitization to common allergens in children is increasing, and animal studies support biological plausibility and causality. The effect of air pollution on respiratory symptoms was suggested to be gender dependent. Previous studies showed that allergy-promoting activity of polystyrene particles (PSP) increased with decreasing particle size after footpad injection of mice. The primary aim of this study was to confirm the influence of particle size on the immunoglobulin E (IgE)-promoting capacity of particles in an airway allergy model. A second aim was to examine whether the allergy-promoting capacity of particles was influenced by gender. Female and male mice were intranasally exposed to the allergen ovalbumin (OVA) with or without ultrafine, fine, or coarse PSP modeling the core of ambient air particles. After intranasal booster immunizations with OVA, serum levels of OVA-specific IgE antibodies, and also markers of airway inflammation and cellular responses in the lung-draining mediastinal lymph nodes (MLN), were determined. PSP of all sizes promoted allergic responses, measured as increased serum concentrations of OVA-specific IgE antibodies. Further, PSP produced eosinophilic airway inflammation and elevated MLN cell numbers as well as numerically reducing the percentage of regulatory T cells. Ultrafine PSP produced stronger allergic responses to OVA than fine and coarse PSP. Although PSP enhanced sensitization in both female and male mice, significantly higher IgE levels and numbers of eosinophils were observed in females than males. However, the allergy-promoting effect of PSP was apparently independent of gender. Thus, our data support the notion that ambient air particle pollution may affect development of allergy in both female and male individuals.

Allergenicity and toxicology of inhaled silver nanoparticles in allergen-provocation mice models

Silver nanoparticles (AgNP) have been associated with the exacerbation of airway hyperresponsiveness. However, the allergenicity and toxicology of AgNP in healthy and allergic individuals are unclear. We investigated the pathophysiological responses to AgNP inhalation in a murine model of asthma. Continuous and stable levels of 33 nm AgNP were maintained at 3.3 mg/m³ during the experimental period. AgNP exposure concomitant with ovalbumin challenge increased the enhanced pause (Penh) in the control and allergic groups. AgNP evoked neutrophil, lymphocyte and eosinophil infiltration into the airways and elevated the levels of allergic markers (immunoglobulin E [IgE] and leukotriene E₄ [LTE₄]), the type 2 T helper (Th2) cytokine interleukin-13 (IL-13), and oxidative stress (8-hydroxy-2′-deoxyguanosine [8-OHdG]) in healthy and allergic mice. Bronchocentric interstitial inflammation was observed after AgNP inhalation. After inhalation, the AgNP accumulated predominantly in the lungs, and trivial amounts of AgNP were excreted in the urine and feces. Furthermore, the AgNP induced inflammatory responses in the peritoneum. The inhalation of AgNP may present safety concerns in healthy and susceptible individuals.

Exposure to multi-walled carbon nanotubes results in aggravation of airway inflammation and remodeling and in increased production of epithelium-derived innate cytokines in a mouse model of asthma

With the development of nanotechnologies, the potential adverse effects of nanomaterials such as multi-walled carbon nanotubes (MWCNT) on the respiratory tract of asthmatics are questioned. Furthermore, investigations are necessary to understand how these effects might arise. In the present study, we hypothesized that epithelium-derived innate cytokines that are considered as important promoting factors in allergy may contribute to an aggravating effect of MWCNT on asthma. We investigated in the mouse the effect of MWCNT on systemic immune response and airway inflammation and remodeling induced by the most frequent allergen so far associated with asthma, house dust mite (HDM), and we examined the production of the innate cytokines thymic stromal lymphopoietin (TSLP), IL-25, IL-33, and GM-CSF. Mice exposed to HDM exhibited specific IgG1 in serum and inflammatory cell infiltration, and increased Th2 cytokine production, mucus hyperproduction, and collagen deposition in the airways when compared to naïve animals. Levels of total IgG1 and HDM-specific IgG1, influx of macrophages, eosinophils and neutrophils, production of collagen, TGF-β1, and mucus, as well as levels of IL-13, eotaxin, and TARC, were dose-dependently increased in mice exposed to HDM and MWCNT compared to HDM alone. These effects were associated with an increased production of TSLP, IL-25, IL-33, and GM-CSF in the airways. Our data demonstrate that MWCNT increase in a dose-dependent manner systemic immune response, as well as airway allergic inflammation and remodeling induced by HDM in the mouse. Our data suggest also a role for airway epithelium and innate cytokines in these effects.

Particle size, chemical composition, seasons of the year and urban, rural or remote site origins as determinants of biological effects of particulate matter on pulmonary cells

Particulate matter (PM), a complex mix of chemical compounds, results to be associated with various health effects. However there is still lack of information on the impact of its different components. PM2.5 and PM1 samples, collected during the different seasons at an urban, rural and remote site, were chemically characterized and the biological effects induced on A549 cells were assessed. A Partial Least Square Discriminant Analysis has been performed to relate PM chemical composition to the toxic effects observed. Results show that PM-induced biological effects changed with the seasons and sites, and such variations may be explained by chemical constituents of PM, derived both from primary and secondary sources. The first-time here reported biological responses induced by PM from a remote site at high altitude were associated with the high concentrations of metals and secondary species typical of the free tropospheric aerosol, influenced by long range transports and aging.

Divergent effects of urban particulate air pollution on allergic airway responses in experimental asthma: a comparison of field exposure studies

BACKGROUND

Increases in ambient particulate matter of aerodynamic diameter of 2.5 μm (PM2.5) are associated with asthma morbidity and mortality. The overall objective of this study was to test the hypothesis that PM2.5 derived from two distinct urban U.S. communities would induce variable responses to aggravate airway symptoms during experimental asthma.

METHODS

We used a mobile laboratory to conduct community-based inhalation exposures to laboratory rats with ovalbumin-induced allergic airways disease. In Grand Rapids exposures were conducted within 60 m of a major roadway, whereas the Detroit was located in an industrial area more than 400 m from roadways. Immediately after nasal allergen challenge, Brown Norway rats were exposed by whole body inhalation to either concentrated air particles (CAPs) or filtered air for 8 h (7:00 AM - 3:00 PM). Both ambient and concentrated PM2.5 was assessed for mass, size fractionation, and major component analyses, and trace element content. Sixteen hours after exposures, bronchoalveolar lavage fluid (BALF) and lung lobes were collected and evaluated for airway inflammatory and mucus responses.

RESULTS

Similar CAPs mass concentrations were generated in Detroit (542 μg/m3) and Grand Rapids (519 μg/m3). Exposure to CAPs at either site had no effects in lungs of non-allergic rats. In contrast, asthmatic rats had 200% increases in airway mucus and had more BALF neutrophils (250% increase), eosinophils (90%), and total protein (300%) compared to controls. Exposure to Detroit CAPs enhanced all allergic inflammatory endpoints by 30-100%, whereas inhalation of Grand Rapids CAPs suppressed all allergic responses by 50%. Detroit CAPs were characterized by high sulfate, smaller sized particles and were derived from local combustion sources. Conversely Grand Rapids CAPs were derived primarily from motor vehicle sources.

CONCLUSIONS

Despite inhalation exposure to the same mass concentration of urban PM2.5, disparate health effects can be elicited in the airways of sensitive populations such as asthmatics. Modulation of airway inflammatory and immune responses is therefore dependent on specific chemical components and size distributions of urban PM2.5. Our results suggest that air quality standards based on particle speciation and sources may be more relevant than particle mass to protect human health from PM exposure.

Serum biochemical analysis to indicate pathogenic risk on mouse Mus musculus exposure to source of drinking water

The 18 biochemical parameters of serum were measured to analyze the pathogenic risks of the Yangtze River Source of Drinking Water in Nanjing area (YZR-SDW-NJ) on mouse Mus musculus for protection of human health in this research. The male mice Mus musculus were sampled and fed with YZR-SDW-NJ for 90 days then the eighteen serum biochemical levels were measured with Automatic Biochemical Analysis/RerLi 600. And the parameter data were treated by One-Way ANOVA statistic approach. The results showed that five parameter levels for the sample group mice were different from those for the control group significantly (0.01 < P or 0.05 < P). Four 4 of the 5 altered parameter levels were decreased including glutamate pyruvate transaminase 38% lower, glutamine-oxaloacetic transaminase 24% lower, triglyceride 76% lower and cystatin C 73% lower, only creatinine level was 26% higher than that in the control group. The data suggest that YZR-SDW-NJ had toxicity on the mouse and the organic pollutants in YZR-SDW-NJ might lead to liver, kidney, cardiovascular and metabolic pathogenic risks on the human beings. The results might be cited as evidence to control pollutants in the source water for the protection of NJ people's health.

Animal models of asthma: value, limitations and opportunities for alternative approaches

Asthma remains an area of considerable unmet medical need. Few new drugs have made it to the clinic during the past 50 years, with many that perform well in preclinical animal models of asthma, failing in humans owing to lack of safety and efficacy. The failure to translate promising drug candidates from animal models to humans has led to questions about the utility of in vivo studies and to demand for more predictive models and tools based on the latest technologies. Following a workshop with experts from academia and the pharmaceutical industry, we suggest here a disease modelling framework designed to better understand human asthma, and accelerate the development of safe and efficacious new asthma drugs that go beyond symptomatic relief.

Proteomic identification of the differentially expressed proteins in human lung epithelial cells by airborne particulate matter

Exposure to airborne PM₁₀, particulate matter with a median aerodynamic diameter of less than 10 µm, is known to be associated with a number of adverse health effects. To gain a better understanding of the cytotoxic mechanism and to develop protein biomarker candidates for PM₁₀-induced toxicity, proteomic analyses were performed in human lung epithelial cells. Two-dimensional gel electrophoresis (2-DE) was followed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) to analyze the proteins differentially expressed by exposure to PM₁₀. Analysis of 2-DE gels revealed more than 1270 protein spots in the cells, of which 36 showed changes of more than 2-fold on exposure to PM₁₀ (up-regulation, n = 6; down-regulation, n = 30). The glycolytic enzyme pyruvate kinase, which also plays a role in tumor metabolism, showed a marked increase in expression, whereas the cytoskeleton-related vinculin and anti-inflammatory annexin 1 showed marked decreases in expression.

Comparison of gene expression profiles induced by coarse, fine, and ultrafine particulate matter

Coarse, fine, and ultrafine particulate matter (PM) fractions possess different physical properties and chemical compositions and may produce different adverse health effects. Studies were undertaken to determine whether or not gene expression patterns may be used to discriminate among the three size fractions. Airway epithelial cells obtained from 6 normal individuals were exposed to Chapel Hill coarse, fine or ultrafine PM (250 μg/ml) for 6 and 24 h (n=3 different individuals each). RNA was isolated and hybridized to Affymetrix cDNA microarrays. Significant genes were identified and mapped to canonical pathways. Expression of selected genes was confirmed by reverse-transcription polymerase chain reaction (RT-PCR). The numbers of genes altered by coarse, fine, and ultrafine PM increased from 0, 6, and 17 at 6 h to 1281, 302, and 455 at 24 h, respectively. The NRF2-mediated oxidative stress response, cell cycle:G2/M DNA damage checkpoint regulation, and mitotic roles of polo-like kinase were the top three pathways altered by all three fractions. Fine and ultrafine PM displayed more similar gene expression patterns. One example was the increased expression of metallothionein isoforms, reflecting the higher zinc content associated with fine and ultrafine fractions. A set of 10 genes was identified that could discriminate fine and ultrafine PM from coarse PM. These results indicate that common properties shared by the three size fractions as well as size-specific factors, e.g., compositions, may determine the effects on gene expression. Genomic markers may be used to discriminate coarse from fine and ultrafine PM.

The impact of nanomaterials in immune system

As a nanotechnology has been actively applied to the overall areas of scientific fields, it is necessary to understand the characteristic features, physical behaviors and the potential effects of exposure to nanomaterials and their toxicity. In this article we review the immunological influences induced by several nanomaterials and emphasize establishment of the animal models to estimate the impact of these nanomaterials on development of immunological diseases.

Induction of chronic inflammation in mice treated with titanium dioxide nanoparticles by intratracheal instillation

Titanium dioxide nanoparticles (TNP) are nanomaterials which have various applications including photocatalysts, cosmetics, and pharmaceuticals because of their high stability, anticorrosiveness, and photocatalytic properties. Induction of cytokines and potential chronic inflammation were investigated in mice treated with TNP (5 mg/kg, 20 mg/kg, and 50 mg/kg) by a single intratracheal instillation. Pro-inflammatory cytokines such as IL-1, TNF-a, and IL-6 were significantly induced in a dose-dependent manner at day 1 after instillation. The levels of Th1-type cytokines (IL-12 and IFN-gamma) and Th2-type cytokines (IL4, IL-5 and IL-10) were also elevated dose-dependently at day 1 and the inflammatory responses were sustained until the remainder of experimental period for 14 days. By the induction of Th2-type cytokines, the increased B cell distributions both in spleen and in blood, and increased IgE production in BAL fluid and serum were observed. In lung tissue, increase of inflammatory proteins (MIP and MCP) and granuloma formation were observed. Furthermore, the expressions of genes related with antigen presentation (H2-T23, H2-T17, H2-K1, and H2-Eb1) and genes related with the induction of chemotaxis of immune cells (Ccl7, Ccl3, Cxcl1, Ccl4, Ccl2) were markedly increased using microarray analysis. From these data, it could be suggested that TNP possibly cause chronic inflammatory diseases through Th2-mediated pathway in mice.