The allergy adjuvant effect of particles - genetic factors influence antibody and cytokine responses

Antiviral potential of nanoparticles for the treatment of Coronavirus infections

BACKGROUND

On 31st December 2019 in Wuhan, China, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was acknowledged. This virus spread quickly throughout the world causing a global pandemic. The World Health Organization declared COVID-19 a pandemic disease on 11th March 2020. Since then, the whole world has come together and have developed several vaccines against this deadly virus. Similarly, several alternative searches for pandemic disease therapeutics are still ongoing. One of them has been identified as nanotechnology. It has demonstrated significant promise for detecting and inhibiting a variety of viruses, including coronaviruses. Several nanoparticles, including gold nanoparticles, silver nanoparticles, quantum dots, carbon dots, graphene oxide nanoparticles, and zinc oxide nanoparticles, have previously demonstrated remarkable antiviral activity against a diverse array of viruses.

OBJECTIVE

This review aims to provide a basic and comprehensive overview of COVID-19's initial global outbreak and its mechanism of infiltration into human host cells, as well as the detailed mechanism and inhibitory effects of various nanoparticles against this virus. In addition to nanoparticles, this review focuses on the role of several antiviral drugs used against COVID-19 to date.

CONCLUSION

COVID-19 has severely disrupted the social and economic lives of people all over the world. Due to a lack of adequate medical facilities, countries have struggled to maintain control of the situation. Neither a drug nor a vaccine has a 100% efficacy rate. As a result, nanotechnology may be a better therapeutic alternative for this pandemic disease.

Exploring the Potential Effects and Mechanisms of Asarum sieboldii Radix Essential Oil for Treatment of Asthma

Asthma, a common chronic pulmonary disorder characterized by airway remodeling, hyperresponsiveness and obstruction, can be aggravated by repeated exposure to particulate matter (PM). The potential effect and mechanisms of Asarum sieboldii Radix essential oil (AEO) against asthma were explored based on network pharmacology. AEO was pre-treated using a nebulizer for 3 weeks and the mice were sensitized to ovalbumin (OVA) and PM10 with the co-treatment of AEO for 4 weeks. In addition, A549 lung epithelial cells were sensitized with PM10 to investigate the underlying mechanisms of AEO regarding the lung-fibrosis-related mediators. The target genes of methyl eugenol, a main compound of AEO, were highly matched by 48% with the gene set of asthma. AEO markedly inhibited the increase in epithelial thickness through the accumulation of goblet cells in the airways. Collagen deposition in the lung tissues of OVA+PM10-challenged asthmatic mice was significantly decreased by AEO. AEO also inhibited the influx of inflammatory cells in the bronchoalveolar lavage fluid, as well as the increases in serum IgE and IgG2a and cytokines in the lung tissues. Furthermore, AEO regulated the expressions of fibrotic mediators, especially POSTN and TGF-β. In conclusion, we expect that AEO can be one of the effective alternative therapeutics to relieve asthma.

Tiron ameliorates oxidative stress and inflammation in a murine model of airway remodeling

Airway remodeling includes lung structural changes that have a role in the irreversibility of pulmonary dysfunction shown in chronic bronchial asthmatics. The current experiment investigated the effect of the mitochondrial antioxidant, tiron in comparison with dexamethasone (DEXA) on airway remodeling in chronic asthma. Sensitized BALB/c mice were challenged with ovalbumin (OVA) aerosol for 8weeks, OVA sensitized-challenged mice were treated with either DEXA or tiron, respectively. After that, lung tissue and bronchoaveolar lavage fluid (BALF) were used for measurement of different biological markers. Lungs were examined for histopathological changes and immunohistochemistry. Upon comparing with vehicle treated animals, trion or DEXA treatment significantly reduced eosinophils, lymphocytes, neutrophils and macrophages count in the BALF. Both drugs significantly alleviated chronic OVA-induced oxidative stress as illustrated by decreased pulmonary malondialdenhyde (MDA) and increased glutathione (GSH) and superoxide dismutase (SOD) levels. Asthmatic mice exhibited elevated levels of NOx, IL-13 and TGF-β1 that were reduced by DEXA and tiron. Histopathological changes and increased immunoreactivity of nuclear factor-Kappa B (NF-κ B) in OVA-challenged mice were minimized by tiron and DEXA treatment. In conclusion, in this model of chronic asthma DEXA and tiron ameliorated airway remodeling and inflammation in experimental chronic asthma with no difference between the effect of tiron and DEXA. Tiron has a potential role as adjuvant treatment in chronic asthma.

Effect of tranilast in comparison with beclomethasone in chronic murine model of asthma

AIM OF THE STUDY

The current investigation was taken to scrutinize the action of tranilast on the airway remodeling in chronic asthma in mice.

MATERIALS AND METHODS

Intraperitoneal injection of ovalbumin was applied to mice for sensitization and subsequent inhalation of 1% ovalbumin three times week for 10 weeks for challenge. Beclomethasone or tranilast were given daily for the 10 week challenge period. At the end of the study, lung weight index, total collagen content, bronchoalveolar lavage level of total and differential cell counts, interleukin-13, in addition to lung tissue nitrate/nitrite and transforming growth beta-1 were measured. Also, histological analysis was done.

RESULTS

Asthmatic mice demonstrated apparent fibrotic changes. Significant airway fibrosis was demonstrated by hyperplasia of goblet cells and thickening of airway epithelium, increased content of lung collagen, lung and bronchoalveolar lavage of transforming growth factor beta-1 and interleukin-13 mutually accompanied by reduction in nitrate/nitrite generation.

CONCLUSIONS

Beclomethasone influence on airway remodeling was mediated mainly via suppression of eosinophilic recruitment into the airways and reduction of interleukin-13 cytokine levels. Whereas, tranilast effects on airway remodeling was found to be mainly mediated via its inhibitory effect on transforming growth beta-1. Both beclomethasone and tranilast influence airway remodeling by different degrees and mechanisms.

Investigations of immunogenic, allergenic and adjuvant properties of Cry1Ab protein after intragastric exposure in a food allergy model in mice

Background

In genetically modified (GM) crops there is a risk that the inserted genes may introduce new allergens and/or adjuvants into the food and feed chain. The MON810 maize, expressing the insecticidal Cry1Ab toxin, is grown in many countries worldwide. In animal models, intranasal and intraperitoneal immunisations with the purified Cry1Ab proteins have induced immune responses, and feeding trials with Cry1Ab-containing feed have revealed some altered immune responses. Previous investigations have primarily measured antibody responses to the protein, while investigations of clinical food allergy symptoms, or allergy promotion (adjuvant effect) associated with the Cry1Ab protein are largely missing. We aimed to investigate immunogenic, allergenic and adjuvant properties of purified Cry1Ab toxin (trypCry1Ab, i.e., trypsin activated Cry1Ab) in a mouse model of food allergy.

Method

Female C3H/HeJ mice were immunized by intragastric gavage of 10 μg purified, trypsin activated Cry1Ab toxin (trypCry1Ab) alone or together with the food allergen lupin. Cholera toxin was added as a positive control for adjuvant effect to break oral tolerance. Clinical symptoms (anaphylaxis) as well as humoral and cellular responses were assessed.

Results

In contrast to results from previous airway investigations, we observed no indication of immunogenic properties of trypCry1Ab protein after repeated intragastric exposures to one dose, with or without CT as adjuvant. Moreover, the results indicated that trypCry1Ab given by the intragastric route was not able to promote allergic responses or anaphylactic reactions against the co-administered allergen lupin at the given dose.

Conclusion

The study suggests no immunogenic, allergenic or adjuvant capacity of the given dose of trypCry1Ab protein after intragastric exposure of prime aged mice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12865-016-0148-x) contains supplementary material, which is available to authorized users.

Assessing particle and fiber toxicology in the respiratory system: the stereology toolbox

The inhalation of airborne particles can lead to pathological changes in the respiratory tract. For this reason, toxicology studies on effects of inhalable particles and fibers often include an assessment of histopathological alterations in the upper respiratory tract, the trachea and/or the lungs. Conventional pathological evaluations are usually performed by scoring histological lesions in order to obtain "quantitative" information and an estimation of the severity of the lesion. This approach not only comprises a potential subjective bias, depending on the examiner's judgment, but also conveys the risk that mild alterations escape the investigator's eye. The most accurate way of obtaining unbiased quantitative information about three-dimensional (3D) features of tissues, cells, or organelles from two-dimensional physical or optical sections is by means of stereology, the gold standard of image-based morphometry. Nevertheless, it can be challenging to express histopathological changes by morphometric parameters such as volume, surface, length or number only. In this review we therefore provide an overview on different histopathological lesions in the respiratory tract associated with particle and fiber toxicology and on how to apply stereological methods in order to correctly quantify and interpret histological lesions in the respiratory tract. The article further aims at pointing out common pitfalls in quantitative histopathology and at providing some suggestions on how respiratory toxicology can be improved by stereology. Thus, we hope that this article will stimulate scientists in particle and fiber toxicology research to implement stereological techniques in their studies, thereby promoting an unbiased 3D assessment of pathological lesions associated with particle exposure.

Compartmental and temporal dynamics of chronic inflammation and airway remodelling in a chronic asthma mouse model

BACKGROUND

Allergic asthma is associated with chronic airway inflammation and progressive airway remodelling. However, the dynamics of the development of these features and their spontaneous and pharmacological reversibility are still poorly understood. We have therefore investigated the dynamics of airway remodelling and repair in an experimental asthma model and studied how pharmacological intervention affects these processes.

METHODS

Using BALB/c mice, the kinetics of chronic asthma progression and resolution were characterised in absence and presence of inhaled corticosteroid (ICS) treatment. Airway inflammation and remodelling was assessed by the analysis of bronchoalveolar and peribronichal inflammatory cell infiltrate, goblet cell hyperplasia, collagen deposition and smooth muscle thickening.

RESULTS

Chronic allergen exposure resulted in early (goblet cell hyperplasia) and late remodelling (collagen deposition and smooth muscle thickening). After four weeks of allergen cessation eosinophilic inflammation, goblet cell hyperplasia and collagen deposition were resolved, full resolution of lymphocyte inflammation and smooth muscle thickening was only observed after eight weeks. ICS therapy when started before the full establishment of chronic asthma reduced the development of lung inflammation, decreased goblet cell hyperplasia and collagen deposition, but did not affect smooth muscle thickening. These effects of ICS on airway remodelling were maintained for a further four weeks even when therapy was discontinued.

CONCLUSIONS

Utilising a chronic model of experimental asthma we have shown that repeated allergen exposure induces reversible airway remodelling and inflammation in mice. Therapeutic intervention with ICS was partially effective in inhibiting the transition from acute to chronic asthma by reducing airway inflammation and remodelling but was ineffective in preventing smooth muscle hypertrophy.

Zinc oxide nanoparticles provide an adjuvant effect to ovalbumin via a Th2 response in Balb/c mice

Zinc oxide nanoparticles (ZNPs) have been used in dietary supplements and may cause an immunomodulatory effect. The present study investigated the effect of ZNPs on antigen-specific immune responses in mice sensitized with the T-cell-dependent antigen ovalbumin (OVA). BALB/c mice were intraperitoneally administered ZNPs (0.25, 0.5, 1 and 3mg) once, in combination with OVA, and the serum antibodies, splenocyte reactivity and activation of antigen-presenting cells were examined. The serum levels of OVA-specific IgG1 and IgE were found significantly enhanced by treatment with ZNPs over control. An increased level of IL-2, IL-4, IL-6, IL-17 and decreased level of IL-10 and TNF-α in splenocytes administered with ZNPs were observed in comparison with control. The ZNPs and OVA-stimulated T lymphocytes showed enhanced proliferation compared with control. Macrophages and B cells showed high expression of MHC class II, whereas higher expression of CD11b in macrophages of the ZNPs and ZNPs/OVA treated groups was observed. The lungs and spleen had increased eosinophils and mast cell numbers. Also, myeloperoxidase activity in lungs was found to be increased by 2.5-fold in the case of ZNPs and 3.75-fold increase in ZNPs/OVA, whereas in intestine, there was significant increase in both the groups. Increased expression of the genes for GATA-3, SOCS-3, TLR-4, IL-13 and IL-5 in the intestine was observed. Collectively, these data indicate that systemic exposure to a single administration of ZNPs could enhance subsequent antigen-specific immune reactions, including the serum production of antigen-specific antibodies, and the functionality of T cells.

Particulate adjuvant and innate immunity: past achievements, present findings, and future prospects

Particulates and crystals stimulate the immune system to induce inflammatory responses. Several nanometer- to micrometer-sized particulates, such as particle matter 2.5 (PM2.5), diesel particles, and sand dust, induce pulmonary inflammation and allergic asthma. Conversely, nanometer- to micrometer-sized crystal, sphere, and hydrogel forms of aluminum salts (referred to as “alum”) have been used as vaccine adjuvants to enhance antibody responses in animals and humans. Although most of these particulates induce type-2 immune responses in vivo, the molecular and immunological mechanisms of action as a vaccine adjuvant are poorly understood. In this review, recent advances in particulate adjuvant research from the standpoint of innate immune responses are discussed.

Nanoscale size control of protein aggregates

Herein, a novel method to synthesize soluble, sub-micrometer sized protein aggregates is demonstrated by mixing native and denatured proteins without using bacteria and contaminating proteins. Ovalbumin (OVA) is employed as a model protein. The average size of the formed aggregates can be controlled by adjusting the fraction of denatured protein in the sample and it is possible to make unimodal size distributions of protein aggregates. OVA aggregates with a size of ∼95 nm are found to be more immunogenic compared to native OVA in a murine splenocyte proliferation assay. These results suggest that the novel method of engineering size specific sub-micrometer sized aggregates may constitute a potential route to increasing the efficacy of protein vaccines. The protein aggregates may also be promising for use in other applications including the surface functionalization of biomaterials and as industrial catalysis materials.

Determinants of experimental allergic responses: interactions between allergen dose, sex and age

The prevalence of allergic diseases is influenced by sex and age. Although mouse models are widely used in allergy research, few experimental studies have examined the interaction effects of sex and age on allergy outcomes. Our aim was to investigate the individual and combined effects of sex and age on allergic sensitization and inflammation in two mouse models: an intraperitoneal (i.p.) and an intranasal (i.n.) sensitization model. We also investigated how the allergen immunization dose interacted with age and sex in the i.p. model. Female and male mice were immunized i.p. or i.n. with ovalbumin when 1, 6 or 20 weeks old. In both models, allergen challenges were performed by i.n. delivery. Serum antibodies, draining lymph node cytokine release and airway inflammatory responses were assessed. In the i.p. model, the antibody and cytokine levels and airway inflammation were highly influenced by immunization dose and age. The responses increased with age when using a low immunization dose, but decreased with age when using a high immunization dose. In the i.n. model, antibody production and airway tissue inflammation increased with age. Female compared with male mice generally developed more pronounced antibody and inflammatory responses. Relative to older mice, juvenile mice had augmented airway inflammation to allergen exposures. The study demonstrates that immunization dose, sex and age are highly influential on allergy outcomes. To better mimic different life stages of human allergic airway disease, murine models, therefore, require careful optimization.

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

In the European Union (EU)-funded project Respiratory Allergy and Inflammation due to Ambient Particles (RAIAP), coarse and fine ambient particulate matter (PM) was collected at traffic dominated locations in Oslo, Rome, Lodz, and Amsterdam, in the spring, summer, and winter 2001/2002. PM was also collected in de Zilk, a rural seaside background location in the Netherlands. The aim of this study was to screen the ambient PM fractions for allergy adjuvant activity measured as the production of allergen- (ovalbumin-) specific immunoglobulin (Ig) E following subcutaneous (sc) injection into the footpad of mice. A second aim was to determine whether the 6-d popliteal lymph node (PLN) assay can be used to detect an allergy adjuvant activity. Allergy screening for IgE adjuvant activity showed that in the presence of ovalbumin (Ova) 12 out of 13 of the fine ambient PM fractions exerted a significant IgE adjuvant activity. In contrast, only 3 out of 13 of the coarse PM fractions had significant adjuvant activity. Overall, fine ambient PM exerted significantly greater IgE adjuvant activity per unit mass than coarse PM. No significant differences were observed between locations or seasons. Substantial higher levels of specific components of PM such as vanadium (V), nickel (Ni), zinc (Zn), ammonium (NH(4)), and sulfate (SO(4)) were present in the fine compared to coarse PM fractions. However, differences in the content of these components among fine PM fractions did not reflect the variation in the levels of IgE anti-Ova. Still, when comparing all seasons overall, positive correlations were observed between V, Ni, and SO(4) and the allergen specific IgE levels. The PLN responses (weight and cell number) to Ova and ambient PM in combination were significantly higher than to Ova or PM alone. Still, the PLN assay appears not to be useful as a quantitative assay for screening of allergy adjuvant activity since no correlation was observed between PLN responses and allergen specific IgE levels. In conclusion, fine ambient PM fractions consistently were found to increase the allergen-specific IgE responses more than the coarse ones. Our finding is in agreement with the notion that traffic-related air pollution contributes to the disease burden in asthma and allergy, and points to fine and ultrafine ambient PM as the most important fractions in relation to allergic diseases.

Links between Pollen, Atopy and the Asthma Epidemic

Pollen allergy has been found in 80-90% of childhood asthmatics and 40-50% of adult-onset asthmatics. Despite the high prevalence of atopy in asthmatics, a causal relationship between the allergic response and asthma has not been clearly established. Pollen grains are too large to penetrate the small airways where asthma occurs. Yet pollen cytoplasmic fragments are respirable and are likely correlated with the asthmatic response in allergic asthmatics. In this review, we outline the mechanism of pollen fragmentation and possible pathophysiology of pollen fragment-induced asthma. Pollen grains rupture within the male flowers and emit cytoplasmic debris when winds or other disturbances disperse the pollen. Peak levels of grass and birch pollen allergens in the atmosphere correlated with the occurrence of moist weather conditions during the flowering period. Thunderstorm asthma epidemics may be triggered by grass pollen rupture in the atmosphere and the entrainment of respirable-sized particles in the outflows of air masses at ground level. Pollen contains nicotinamide adenine dinucleotide phosphate (reduced) oxidases and bioactive lipid mediators which likely contribute to the inflammatory response. Several studies have examined synergistic effects and enhanced immune response from interaction in the atmosphere, or from co-deposition in the airways, of pollen allergens, endogenous pro-inflammatory agents, and the particulate and gaseous fraction of combustion products. Pollen and fungal fragments also contain compounds that can suppress reactive oxidants and quench free radicals. It is important to know more about how these substances interact to potentially enhance, or even ameliorate, allergic asthma.

Pollinex Quattro: a novel and well-tolerated, ultra short-course allergy vaccine

Pollinex Quattro is a novel, ultra short-course vaccine for treatment of seasonal allergic rhinitis from grass, tree or ragweed pollen allergy. Its unique formulation combines chemically modified allergens adsorbed onto a L-tyrosine depot to enhance tolerability with the novel adjuvant, monophosphoryl lipid A, to improve efficacy. Controlled clinical studies indicate that four preseasonal injections with grass or tree formulations significantly reduce rhinoconjunctivitis symptoms and medication use, as well as elevate allergen-specific immunoglobulin G and blunt elevation of immunoglobulin E upon allergen exposure. Postmarketing surveillance studies indicate similar clinical outcomes. In all cases, the allergy vaccine was well tolerated with minimal local reactions, while systemic reactions were rare and mild. Results from recent investigational trials with grass and ragweed formulations are consistent with previous efficacy and safety outcomes, and will be used toward product registration in North America.

Popliteal lymph node (PLN) assay to study adjuvant effects on respiratory allergy

Different variants of the popliteal lymph node (PLN) assay have been published. Here we describe the adjuvant popliteal lymph node assay, an immune response assay to study the adjuvant activity of soluble substances as well as particulate matter. The substance to be studied for adjuvant activity is injected into the hind footpad of mice or rats together with an antigen. Adjuvant activity is determined as the increase in PLN weight and cell numbers in animals receiving antigen together with the substance under study, compared with PLN weight and cell numbers in animals given the antigen without the substance in question, and animals given the putative adjuvant alone. Because lymph node weight and cell numbers are immunologically non-specific parameters, specific immune response assays like serum antibody responses or antibody-forming cell numbers should additionally be performed. Different antigens and immune response assays may be used, depending on the research question asked. In relation to respiratory (or food) allergy, the assays should as a minimum include determination of specific IgE in serum, and preferably also IgG1 (mouse). Serum specific IgG2a antibody determination may be added to get an indication of the Th1-Th2-balance of the response. The adjuvant PLN assay, with cellular response assays performed in the draining popliteal lymph node and antibody determinations in serum, requires small amounts of test material. The assay offers a practical, sensitive and reproducible method to determine the adjuvant activity of soluble substances as well as particulate material, with the possibility to also perform mechanistic studies.

Adjuvant effects of inhaled mono-2-ethylhexyl phthalate in BALB/cJ mice

Phthalates, including di(2-ethylhexyl) phthalate (DEHP), are widely used and have been linked with the development of wheezing and asthma. The main metabolite of DEHP, mono-2-ethylhexyl phthalate (MEHP), was investigated for adjuvant effects in a mouse inhalation model. BALB/cJ mice were exposed to aerosols of 0.03 or 0.4 mg/m(3) MEHP 5 days/week for 2 weeks and thereafter weekly for 12 weeks together with a low dose of ovalbumin (OVA) as a model allergen. Mice exposed to OVA alone or OVA+Al(OH)(3) served as negative and positive controls, respectively. Finally, all groups were exposed to a nebulized 1% OVA solution on 3 consecutive days to investigate the development of an inflammatory response. Serum, bronchoalveolar lavage (BAL) fluid, and draining lymph nodes were collected 24h later. In the OVA+Al(OH)(3) group, significantly increased levels of OVA-specific IgE and IgG1 in serum as well as of eosinophils in BAL fluid were observed. OVA-specific IgG1 production in both MEHP groups was significantly increased. OVA-specific IgE and IgG2a were not increased significantly. A dose-dependent increase in inflammatory cells was observed in BAL fluid, leading to significantly higher lymphocyte and eosinophil numbers in the OVA+0.4 mg/m(3) MEHP group. Ex vivo cytokine secretion by cultures of draining lymph nodes suggested a T(H)2 profile of MEHP. In conclusion, MEHP acted as a T(H)2 adjuvant after inhalation. However, it is suggested that the inflammation in the MEHP groups was primarily mediated by an IgG1-dependent mechanism. To address implications for humans, a margin-of-exposure was estimated based on the lack of significant effects on IgE production and inflammation after exposures to 0.03 mg/m(3) MEHP observed in the present study and estimated human exposure levels.

Traffic-related air pollutants induce the release of allergen-containing cytoplasmic granules from grass pollen

BACKGROUND/AIM

Pollen cytoplasmic granules (PCG) are loaded with allergens. They are released from grass pollen grains following contact with water and can form a respirable allergenic aerosol. On the other hand, the traffic-related air pollutants NO2 and O3 are known to be involved in the current increase in the prevalence of allergic diseases via their adjuvant effects. Our objective was to determine the effects of air pollutants on the release of PCG from Phleum pratense (timothy grass) pollen.

METHODS

P. pratense pollen was exposed to several concentrations of NO2 and O3. The induced morphological damages were observed by environmental scanning electron microscopy, and the amount of PCG released from the pollen upon contact with water was measured.

RESULTS

The percentages of damaged grain were 6.4% in air-treated controls, 15% after treatment with the highest NO2 dose (50 ppm) and 13.5% after exposure to 0.5 ppm O3. In treated samples, a fraction of the grains spontaneously released their PCG. Upon subsequent contact with water, the remaining intact grains released more PCG than pollen exposed to air only.

CONCLUSIONS

Traffic-related pollutants can trigger the release of allergen-containing granules from grass pollen, and increase the bioavailability of airborne pollen allergens. This is a new mechanism by which air pollution concurs with the current increase in the prevalence of allergic diseases.