Effectiveness and safety of oral lactococci-based vaccine encoding triple common allergens to prevent airway allergy in mice

Allergic airway disease is the most common chronic airway inflammatory disorder in developed countries. House dust mite, cockroach, and mold are the leading allergens in most tropical and subtropical countries, including Taiwan. As allergen avoidance is difficult for patients allergic to these perennial indoor allergens, allergen-specific immunotherapy (ASIT) is the only available allergen-specific and disease-modifying treatment. However, for patients sensitized to multiple allergens, ASIT using each corresponding allergen is cumbersome. In the present study, we developed a recombinant L. lactis vaccine against the three most common indoor aeroallergens and investigated its effectiveness for preventing respiratory allergy and safety in mice. Three recombinant clones of Der p 2 (mite), Per a 2 (roach), and Cla c 14 (mold) were constructed individually in pNZ8149 vector and then electroporated into host strain L.lactis NZ3900. BALB/c mice were fed with the triple vaccine 5 times per week for 4 weeks prior to sensitization. The effectiveness and safety profile were then determined. Oral administration of the triple vaccine significantly alleviated allergen-induced airway hyper-responsiveness in the vaccinated mice. The allergen-specific IgG2a was upregulated. IL-4 and IL-13 mRNA expressions as well as inflammatory cell infiltration in the lungs decreased significantly in the vaccinated groups. No body weight loss or abnormal findings in the liver and kidneys were found in any of the groups of mice. This is the first report to describe a triple-aeroallergen vaccine using a food-grade lactococcal expression system. We developed a convenient oral delivery system and intend to extend this research to develop a vaccination that can be self-administered at home by patients.

Microbial metabolism of L-tyrosine protects against allergic airway inflammation

The constituents of the gut microbiome are determined by the local habitat, which itself is shaped by immunological pressures, such as mucosal IgA. Using a mouse model of restricted antibody repertoire, we identified a role for antibody-microbe interactions in shaping a community of bacteria with an enhanced capacity to metabolize L-tyrosine. This model led to increased concentrations of p-cresol sulfate (PCS), which protected the host against allergic airway inflammation. PCS selectively reduced CCL20 production by airway epithelial cells due to an uncoupling of epidermal growth factor receptor (EGFR) and Toll-like receptor 4 (TLR4) signaling. Together, these data reveal a gut microbe-derived metabolite pathway that acts distally on the airway epithelium to reduce allergic airway responses, such as those underpinning asthma.

A phospholipid-based formulation for the treatment of airway inflammation in chronic respiratory diseases

Inflammation, the major hallmark of all chronic respiratory diseases is generally managed by inhaled corticosteroids. However, long term high dose treatment can result in significant side effects. Hence, there is a medical need for non-steroidal anti-inflammatory therapies to address airway inflammation. Phospholipids have been shown to reduce inflammation in several inflammatory conditions; however, their clinical translation has been limited to liposomal formulations traditionally used as drug carriers and their biological activity has not been investigated. Here we report the first application of empty liposomes as an anti-inflammatory treatment in airway inflammation. In the current study, liposomes (UTS-001) were prepared from cholesterol and a synthetic phospholipid (DOPC). The formulation was characterised in terms of size, charge, polydispersity index, morphology and stability as colloidal suspension and freeze-dried nanoparticles. Time-dependant uptake of UTS-001 in airway epithelial cells was observed which was inhibited by nystatin demonstrating that the uptake is via the caveolae pathway. In-vitro, in primary nasal epithelial cells, UTS-001 treatment successfully attenuated IL-6 levels following TNF-α stimulation. Consistent with the in-vitro findings, in-vivo, in the ovalbumin model of allergic airway inflammation, UTS-001 significantly reduced total immune cell counts in bronchoalveolar lavage fluid and reduced airway hyperresponsiveness in response to increasing doses of methacholine challenge. Therefore, our results establish UTS-001 as a potential anti-inflammatory treatment that may be useful as a therapeutic for lung inflammatory diseases.

Androgens augment pulmonary responses to ozone in mice

Ozone causes airway hyperresponsiveness, a defining feature of asthma, and is an asthma trigger. In mice, ozone-induced airway hyperresponsiveness is greater in males than in females, suggesting a role for sex hormones in the response to ozone. To examine the role of androgens in these sex differences, we castrated 4-week-old mice. Controls underwent sham surgery. At 8 weeks of age, mice were exposed to ozone (2ppm, 3 h) or room air. Twenty-four hours later, mice were anesthetized and measurements of airway responsiveness to inhaled aerosolized methacholine were made. Mice were then euthanized and bronchoalveolar lavage was performed. Castration attenuated ozone-induced airway hyperresponsiveness and reduced bronchoalveolar lavage cells. In intact males, flutamide, an androgen receptor inhibitor, had similar effects to castration. Bronchoalveolar lavage concentrations of several cytokines were reduced by either castration or flutamide treatment, but only IL-1α was reduced by both castration and flutamide. Furthermore, an anti-IL-1α antibody reduced bronchoalveolar lavage neutrophils in intact males, although it did not alter ozone-induced airway hyperresponsiveness. Our data indicate that androgens augment pulmonary responses to ozone and that IL-1α may contribute to the effects of androgens on ozone-induced cellular inflammation but not airway hyperresponsiveness.

Heterogeneous photo-Fenton degradation of formaldehyde using MIL-100(Fe) under visible light irradiation

Removal of toxic formaldehyde from environmental waters is crucial to maintain ecosystem sustainability and human health. In this work, MIL-100(Fe) as a heterogeneous Fenton-like photocatalyst was used for the treatment of formaldehyde-contaminated water. The MIL-100(Fe) was synthesized via a facile solvothermal method and fully characterized using different spectroscopic and microscopic techniques. Based on the results, the formation of highly porous, crystalline, and stable visible light-responsive MIL-100(Fe) was confirmed. The Fenton-like photocatalytic efficiency of the MIL-100(Fe) toward the degradation of formaldehyde was then studied under visible light irradiation. For this purpose, the effect of initial concentration of formaldehyde, photocatalyst dose, H₂O₂ concentration, solution pH, and contact time on the removal efficiency of the MIL-100(Fe) was investigated using central composite design. The obtained results showed that the removal efficiency of the MIL-100(Fe) is significantly affected by the initial concentration of formaldehyde. A second-order model with R² = 0.93 was developed for the system that was able to adequately predict the percentage removal of formaldehyde by the MIL-100(Fe) under different experimental conditions. According to the numerical optimization results, by using 1.13 g L^-1 photocatalyst and 0.055 mol L^-1 H₂O₂, 93% of formaldehyde can be removed after 119 min from an aqueous solution containing 700 mg L^-1 of formaldehyde at pH 6.54.

Maternal Fiber Dietary Intakes during Pregnancy and Infant Allergic Disease

Maternal diet during pregnancy plays a likely role in infant immune development through both direct nutrient specific immunomodulatory effects and by modulating the composition and metabolic activity of the maternal gut microbiome. Dietary fibers, as major substrates for microbial fermentation, are of interest in this context. This is the first study to examine maternal intakes of different fiber sub-types and subsequent infant allergic disease. In an observational study of 639 mother–infant pairs (all infants had a family history of allergic disease) we examined maternal intakes of total fiber, soluble fiber, insoluble fiber, resistant starch, and prebiotic fiber, by a semi-quantitative food frequency questionnaire at 36–40 weeks’ gestation. Infants attended an allergy clinical assessment at 12 months of age, including skin prick testing to common allergens. Higher maternal dietary intakes of resistant starch were associated with reduced doctor diagnosed infant wheeze, adjusted odds ratio (aOR) 0.68 (95% CI 0.49, 0.95, p = 0.02). However, in contrast, higher maternal intakes of resistant starch were associated with higher risk of parent reported eczema aOR 1.27 (95% CI 1.09, 1.49, p < 0.01) and doctor diagnosed eczema aOR 1.19 (95% CI 1.01, 1.41, p = 0.04). In conclusion, maternal resistant starch consumption was differentially associated with infant phenotypes, with reduced risk of infant wheeze, but increased risk of eczema.

Caloric restriction prevents the development of airway hyperresponsiveness in mice on a high fat diet

We have previously shown that high fat diet (HFD) for 2 weeks increases airway hyperresponsiveness (AHR) to methacholine challenge in C57BL/6J mice in association with an increase in IL-1β levels in lung tissue. We hypothesize that obesity increases AHR via the IL-1β mechanism, which can be prevented by caloric restriction and IL-1β blockade. In this study, we fed C57BL/6J mice for 8 weeks with several hypercaloric diets, including HFD, HFD supplemented with fructose, high trans-fat diet (HTFD) supplemented with fructose, either ad libitum or restricting their food intake to match body weight to the mice on a chow diet (CD). We also assessed the effect of the IL-1β receptor blocker anakinra. All mice showed the same total respiratory resistance at baseline. All obese mice showed higher AHR at 30 mg/ml of methacholine compared to CD and food restricted groups, regardless of the diet. Obese mice showed significant increases in lung IL-1 β mRNA expression, but not the protein, compared to CD and food restricted mice. Anakinra abolished an increase in AHR. We conclude that obesity leads to the airway hyperresponsiveness preventable by caloric restriction and IL-1β blockade.

High molecular weight hyaluronan ameliorates allergic inflammation and airway hyperresponsiveness in the mouse

Allergic asthma is a major cause of morbidity in both pediatric and adult patients. Recent research has highlighted the role of hyaluronan (HA), an extracellular matrix glycosaminoglycan, in asthma pathogenesis. Experimental allergic airway inflammation and clinical asthma are associated with an increase of shorter fragments of HA (sHA), which complex with inter-α-inhibitor heavy chains (HCs) and induce inflammation and airway hyperresponsiveness (AHR). Importantly, the effects of sHA can be antagonized by the physiological counterpart high molecular weight HA (HMWHA). We used a mouse model of house dust mite-induced allergic airway inflammation and demonstrated that instilled HMWHA ameliorated allergic airway inflammation and AHR, even when given after the establishment of allergic sensitization and after challenge exposures. Furthermore, instilled HMWHA reduced the development of HA-HC complexes and the activation of Rho-associated, coiled-coil containing protein kinase 2. We conclude that airway application of HMWHA is a potential treatment for allergic airway inflammation.

Andrographolide prevented toluene diisocyanate-induced occupational asthma and aberrant airway E-cadherin distribution via p38 MAPK-dependent Nrf2 induction

Toluene diisocyanate (TDI) is a major cause of chemical-induced occupational asthma, which contributes about 15% of global asthma burden. Resistance and compounded side effects associated with the use of corticosteroid in asthma necessitate the search for alternative drugs. Andrographolide (AGP), a naturally occurring diterpene lactone is known to exhibit various bioactivities. Its ability to ameliorate cardinal features of allergic asthma was previously suggested in an eosinophilic asthma endotype. However, its potential antiasthma activity and mechanism of action in a neutrophilic occupational asthma model, as well as its effect on epithelial dysfunction remain unknown. BALB/c mice were dermally sensitised with 0.3% TDI or acetone olive oil (AOO) vehicle on day 1 and 8, followed by 0.1% TDI intranasal challenge on days 15, 18 and 21. Endpoints were evaluated via bronchoalveolar lavage fluid (BALF) cell analysis, 2',7'-dichlorofluorescein diacetate (DCFDA) assays, immunoblotting, immunohistochemistry and methacholine challenge test. Decreases in total and differential leukocyte counts of BALF were recorded in AGP-treated animals. The compound dose-dependently reduced intracellular de-esterification of DCFDA, thus suggesting AGP's potential to inhibit intracellular reactive oxygen species (ROS). Mechanistically, the treatment prevented TDI-induced aberrant E-cadherin distribution and restored airway epithelial β-catenin at cell to cell contact site. Furthermore, AGP ameliorated TDI induced pulmonary collagen deposition. In addition, the treatment significantly upregulated pulmonary HO-1, Nrf2 and phospho-p38 levels. Airway hyperresponsiveness was markedly suppressed among AGP-treated animals. Collectively, these findings suggest AGP's protective function against TDI-induced airway epithelial barrier dysfunction and oxidative lung damage possibly through the upregulation of adherence junction proteins and the activation of p38/Nrf2 signalling. This study elucidates the therapeutic potential of AGP in the control and management of chemical-induced allergic asthma. To the best of our knowledge, the potential anti-asthma activity of AGP in TDI-induced occupational asthma has not been reported previously.

Potential Exposure and Cancer Risk from Formaldehyde Emissions from Installed Chinese Manufactured Laminate Flooring

Lumber Liquidators (LL) Chinese-manufactured laminate flooring (CLF) has been installed in >400,000 U.S. homes over the last decade. To characterize potential associated formaldehyde exposures and cancer risks, chamber emissions data were collected from 399 new LL CLF, and from LL CLF installed in 899 homes in which measured aggregate indoor formaldehyde concentrations exceeded 100 μg/m³ from a total of 17,867 homes screened. Data from both sources were combined to characterize LL CLF flooring-associated formaldehyde emissions from new boards and installed boards. New flooring had an average (±SD) emission rate of 61.3 ± 52.1 μg/m² -hour; >one-year installed boards had ∼threefold lower emission rates. Estimated emission rates for the 899 homes and corresponding data from questionnaires were used as inputs to a single-compartment, steady-state mass-balance model to estimate corresponding residence-specific TWA formaldehyde concentrations and potential resident exposures. Only ∼0.7% of those homes had estimated acute formaldehyde concentrations >100 μg/m³ immediately after LL CLF installation. The TWA daily formaldehyde inhalation exposure within the 899 homes was estimated to be 17 μg/day using California Proposition 65 default methods to extrapolate cancer risk (below the regulation "no significant risk level" of 40 μg/day). Using a U.S. Environmental Protection Agency linear cancer risk model, 50th and 95th percentile values of expected lifetime cancer risk for residents of these homes were estimated to be 0.33 and 1.2 per 100,000 exposed, respectively. Based on more recent data and verified nonlinear cancer risk assessment models, LL CLF formaldehyde emissions pose virtually no cancer risk to affected consumers.

Role of venlafaxine in prevention of cyclophosphamide-induced lung toxicity and airway hyperactivity in rats

Cyclophosphamide (CP) is a drug used in chemotherapy and management of neoplastic diseases. This study aimed to investigate the prophylactic impacts of venlafaxine against CP-induced lung toxicity in rats. Rats were assigned randomly into 3 groups; control, CP (150 mg/kg) and CP/venlafaxine (50 mg/kg). On the end day, rats were sacrificed then bronchoalveolar fluid (BALF) and lungs were harvested. CP produced significant decrease in animal body weights and significant increase in lung/body weight ratio; levels of LDH, total protein, total and differential cell counts in BALF in comparison with control group. Moreover, significant elevation incontents of MDA, NOx, TNF-α and IL-1β and significant decline in GSH, SOD activities were observed in lung tissues. CP increased the response of tracheal zigzag to ACh. Histopathological results showed that CP increased inflammation and fibrosis in lung tissues. Venlafaxine restored most parameters to the normal levels. This protective effect of venlafaxine could be linked to its ability to reduce oxidative stress and inflammation.

Evaluation of artificially contaminated fish with formaldehyde under laboratory conditions and exposure assessment in freshwater fish in Southern Bangladesh

Formalin can be added as preservative to fresh foods to prevent spoilage and extend shelf life. Formalin contains 37-40% formaldehyde, which is classified as carcinogenic to humans. To assess the public health risk associated with formaldehyde exposure in freshwater fish in Southern Bangladesh, formaldehyde concentrations (mg/kg) were determined in tilapia, Indian major carp rui, Chinese carp and a minor carp from local market and in laboratory simulations (0.5, 1.0, 2.0 and 4.0% formaldehyde solution for 5, 15, 30 and 60 min) with spectrophotometric and high performance liquid chromatography (HPLC) methods. A food frequency questionnaire was used to collect fish consumption (kg/kg BW. d) data from 400 respondents. A probabilistic exposure assessment was conducted using @Risk^®7.0 software. Fish treated with formalin at increasing concentrations and exposure time showed increased trends of formaldehyde acquisition irrespective of fish species and analytical methods used (p < .05). Compared to spectrophotometry, the HPLC method was shown to be more sensitive and is therefore the preferred method for formalin quantification. Maximum exposure to formaldehyde (0.28 mg/kg BW. d) was calculated for tilapia using HPLC analysis. Margin of exposure (MoE) provides high priority (<10,000) for tilapia and Indian major carp rui at P99 under spectrophotometric analysis whereas as determined using HPLC, tilapia had MoE values much lower than 10,000 at P99, P95 and P90 (both total population and consumers). Exposure to formaldehyde associated with freshwater fish consumption is a public health concern in Southern Bangladesh and needs further assessment and risk management strategies.

Prophylactic effect of rosmarinic acid on tracheal responsiveness, white blood cell count and oxidative stress markers in lung lavage of sensitized rats

BACKGROUND

Rosmarinic acid (RA) as an active component of several medicinal plants, has shown anti-inflammatory and anti-oxidant effects. In this study, the effect of RA on tracheal responsiveness (TR), lung inflammatory cells, oxidant biomarkers in sensitized rats were evaluated.

METHODS

TR to methacholine and ovalbumin (OVA) as well as total and differential white blood cell (WBC) count and levels of nitrogen dioxide, nitrate, malondialdehyde, thiol, superoxide dismutase, and catalase in bronchoalveolar lavage fluid were measured in control (group C) rats, sensitized animals to OVA and given drinking water alone (group S), S groups receiving drinking water containing three concentrations of RA (0.125, 0.250 and 0.500 mg/mL) and dexamethasone (1.25 μg/mL), (n = 6 in each group).

RESULTS

Increased TR to methacholine and OVA, total WBC count, percentages of eosinophils, monocytes, neutrophils and levels of oxidant biomarkers but decreased other measured parameters were observed in group S compared to group C. Percentages of lymphocytes and antioxidant biomarkers were significantly increased but other measured parameters were significantly decreased in S group treated with dexamethasone and in rats treated with the two higher concentrations of RA compared to S group. The effect of RA medium concentration on percentage of eosinophils and RA high concentration on total WBC count and percentages of eosinophils and lymphocytes, were significantly higher than those of dexamethasone.

CONCLUSION

These results showed the concentration-dependent effect of RA on tracheal responses, lung inflammatory cells and oxidant-antioxidant parameters which was comparable to that of dexamethasone at used concentrations in sensitized rats.

The Interactive Roles of Lipopolysaccharides and dsRNA/Viruses on Respiratory Epithelial Cells and Dendritic Cells in Allergic Respiratory Disorders: The Hygiene Hypothesis

The original hygiene hypothesis declares "more infections in early childhood protect against later atopy". According to the hygiene hypothesis, the increased incidence of allergic disorders in developed countries is explained by the decrease of infections. Epithelial cells and dendritic cells play key roles in bridging the innate and adaptive immune systems. Among the various pattern-recognition receptor systems of epithelial cells and dendritic cells, including toll-like receptors (TLRs), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) and others, TLRs are the key systems of immune response regulation. In humans, TLRs consist of TLR1 to TLR10. They regulate cellular responses through engagement with TLR ligands, e.g., lipopolysaccharides (LPS) acts through TLR4 and dsRNA acts through TLR3, but there are certain common components between these two TLR pathways. dsRNA activates epithelial cells and dendritic cells in different directions, resulting in allergy-related Th2-skewing tendency in epithelial cells, and Th1-skewing tendency in dendritic cells. The Th2-skewing effect by stimulation of dsRNA on epithelial cells could be suppressed by the presence of LPS above some threshold. When LPS level decreases, the Th2-skewing effect increases. It may be via these interrelated networks and related factors that LPS modifies the allergic responses and provides a plausible mechanism of the hygiene hypothesis. Several hygiene hypothesis-related phenomena, seemingly conflicting, are also discussed in this review, along with their proposed mechanisms.

Effects of VLA-1 Blockade on Experimental Inflammation in Mice

VLA-1 (very late antigen-1) is implicated in recruitment, retention and activation of leukocytes and its blockade has been referred as a potential target of new drug discovery to address unmet medical needs in inflammatory disease area. In the present study, we investigate the effects of an anti-murine CD49a (integrin α subunit of VLA-1) monoclonal antibody (Ha31/8) on various experimental models of inflammatory diseases in mice. Pretreatment with Ha31/8 at an intraperitoneal dose of 250 µg significantly (P<0.01) reduced arthritic symptoms and joint tissue damage in mice with type II collagen-induced arthritis. In addition, Ha31/8 at an intraperitoneal dose of 100 µg significantly (P<0.01) inhibited airway inflammatory cell infiltration induced by repeated exposure to cigarette smoke. In contrast, Ha31/8 failed to inhibit oxazolone-induced chronic dermatitis and OVA-induced airway hyperresponsiveness at an intraperitoneal dose of 100 µg. These results show that VLA-1 is involved, at least partly, in the pathogenesis of type II collagen-induced arthritis and cigarette smoke-induced airway inflammatory cell infiltration in mice, indicating the therapeutic potential of VLA-1 blockade against rheumatoid arthritis and chronic occlusive pulmonary disease.

TLR2, TLR4 AND MyD88 Mediate Allergic Airway Disease (AAD) and Streptococcus pneumoniae-Induced Suppression of AAD

Background

Exposure to non-pathogenic Streptococcus pneumoniae and vaccination are inversely associated with asthma. Studies in animal models demonstrate that airway administration of S. pneumoniae (live or killed), or its vaccines or components, suppresses the characteristic features of asthma in mouse models of allergic airway disease (AAD). These components could be developed into immunoregulatory therapies. S. pneumoniae components are recognized by Toll-like receptors (TLR) 2 and TLR4, and both induce inflammatory cell responses through the adaptor protein myeloid differentiation primary response gene 88 (MyD88). The involvement of TLR2, TLR4 and MyD88 in the pathogenesis of AAD and asthma is incompletely understood, and has not been studied in S. pneumoniae-mediated suppression of AAD. We investigated the role of TLR2, TLR4 and MyD88 in the development of AAD and S. pneumoniae-mediated suppression of AAD.

Methods and Findings

OVA-induced AAD and killed S. pneumoniae-mediated suppression of AAD were assessed in wild-type, TLR2^-/-, TLR4^-/-, TLR2/4^-/- and MyD88^-/- BALB/c mice. During OVA-induced AAD, TLR2, TLR4 and MyD88 were variously involved in promoting eosinophil accumulation in bronchoalveolar lavage fluid and blood, and T-helper type (Th)2 cytokine release from mediastinal lymph node T cells and splenocytes. However, all were required for the induction of airways hyperresponsiveness (AHR). In S. pneumoniae-mediated suppression of AAD, TLR2, TLR4 and MyD88 were variously involved in the suppression of eosinophilic and splenocyte Th2 responses but all were required for the reduction in AHR.

Conclusions

These results highlight important but complex roles for TLR2, TLR4 and MyD88 in promoting the development of OVA-induced AAD, but conversely in the S. pneumoniae-mediated suppression of AAD, with consistent and major contributions in both the induction and suppression of AHR. Thus, TLR signaling is likely required for both the development of asthma and the suppression of asthma by S. pneumoniae, and potentially other immunoregulatory therapies.

Testing small molecule analogues of the Acanthocheilonema viteae immunomodulator ES-62 against clinically relevant allergens

ES-62 is a glycoprotein secreted by the filarial nematode Acanthocheilonema viteae that protects against ovalbumin (OVA)-induced airway hyper-responsiveness in mice by virtue of covalently attached anti-inflammatory phosphorylcholine (PC) residues. We have recently generated a library of small molecule analogues (SMAs) of ES-62 based around its active PC moiety as a starting point in novel drug development for asthma and identified two compounds - termed 11a and 12b - that mirror ES-62's protective effects. In this study, we have moved away from OVA, a model allergen, to test the SMAs against two clinically relevant allergens - house dust mite (HDM) and cockroach allergen (CR) extract. We show that both SMAs offer some protection against development of lung allergic responses to CR, in particular reducing eosinophil infiltration, whereas only SMA 12b is effective in protecting against eosinophil-dependent HDM-induced allergy. These data therefore suggest that helminth molecule-induced protection against model allergens may not necessarily translate to clinically relevant allergens. Nevertheless, in this study, we have managed to demonstrate that it is possible to produce synthetic drug-like molecules based on a parasitic worm product that show therapeutic potential with respect to asthma resulting from known triggers in humans.

Side-stream tobacco smoke-induced airway hyperresponsiveness in early postnatal period is involved nerve growth factor

Epidemiological studies have shown that children are more susceptible to adverse respiratory effects of passive smoking than adults. The goal of this study is to elucidate the possible neural mechanism induced by exposure to passive smoking during early life. Postnatal day (PD) 2 and PD 21 mice were exposed to side-stream tobacco smoke (SS), a surrogate to secondhand smoke, or filtered air (FA) for 10 consecutive days. Pulmonary function, substance P (SP) airway innervation, neurotrophin gene expression in lung and nerve growth factor (NGF) release in bronchoalveolar lavage (BAL) fluid were measured at different times after the last SS or FA exposure. Exposure to SS significantly altered pulmonary function in PD2, accompanied with an enhanced SP innervation in airway. However, exposure to SS during the later developmental period (PD21) did not appear to affect pulmonary function and SP innervation of the airways. Interestingly, SS exposure in PD2 group significantly induced an increased gene expression on NGF, and decreased NGF receptor P75 in lung; parallel with high levels of NGF protein in BAL. Furthermore, pretreatment with NGF antibody significantly diminished SS-induced airway hyperresponsivenss and the increased SP airway innervation in the PD2 group. These findings suggest that enhanced NGF released in the lung contributes to SS-enhanced SP tracheal innervation and airway responsiveness in early life.

House dust mite reduction and avoidance measures for treating eczema

BACKGROUND

Eczema is an inflammatory skin disease that tends to involve skin creases, such as the folds of the elbows or knees; it is an intensely itchy skin condition, which can relapse and remit over time. As many as a third of people with eczema who have a positive test for allergy to house dust mite have reported worsening of eczema or respiratory symptoms when exposed to dust.

OBJECTIVES

To assess the effects of all house dust mite reduction and avoidance measures for the treatment of eczema.

SEARCH METHODS

We searched the following databases up to 14 August 2014: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2014, Issue 8), MEDLINE (from 1946), Embase (from 1974), LILACS (from 1982), and the GREAT database. We also searched five trials registers and checked the reference lists of included and excluded studies for further references to relevant studies. We handsearched abstracts from international eczema and allergy meetings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of any of the house dust mite reduction and avoidance measures for the treatment of eczema, which included participants of any age diagnosed by a clinician with eczema as defined by the World Allergy Organization. We included all non-pharmacological and pharmacological interventions that sought to reduce or avoid exposure to house dust mite and their allergenic faeces. The comparators were any active treatment, no treatment, placebo, or standard care only.

DATA COLLECTION AND ANALYSIS

Two authors independently checked the titles and abstracts identified, and there were no disagreements. We contacted authors of included studies for additional information. We assessed the risk of bias using Cochrane methodology.

MAIN RESULTS

We included seven studies of 324 adults and children with eczema. Overall, the included studies had a high risk of bias. Four of the seven trials tested interventions with multiple components, and three tested a single intervention. Two of the seven trials included only children, four included children and adults, and one included only adults. Interventions to reduce or avoid exposure to house dust mite included covers for mattresses and bedding, increased or high-quality vacuuming of carpets and mattresses, and sprays that kill house dust mites.Four studies assessed our first primary outcome of 'Clinician-assessed eczema severity using a named scale'. Of these, one study (n = 20) did not show any significant short-term benefit from allergen impermeable polyurethane mattress encasings and acaricide spray versus allergen permeable cotton mattress encasings and placebo acaricide spray. One study (n = 60) found a modest statistically significant benefit in the Six Area, Six Sign Atopic Dermatitis (SASSAD) scale over six months (mean difference of 4.2 (95% confidence interval 1.7 to 6.7), P = 0.008) in favour of a mite impermeable bedding system combined with benzyltannate spray and high-filtration vacuuming versus mite permeable cotton encasings, water with a trace of alcohol spray, and a low-filtration vacuum cleaner. The third study (n = 41) did not compare the change in severity of eczema between the two treatment groups. The fourth study (n = 86) reported no evidence of a difference between the treatment groups.With regard to the secondary outcomes 'Participant- or caregiver-assessed global eczema severity score' and the 'Amount and frequency of topical treatment required', one study (n = 20) assessed these outcomes with similar results being reported for these outcomes in both groups. Four studies (n = 159) assessed 'Sensitivity to house dust mite allergen using a marker'; there was no clear evidence of a difference in sensitivity levels reported between treatments in any of the four trials.None of the seven included studies assessed our second primary outcome 'Participant- or caregiver-assessed eczema-related quality of life using a named instrument' or the secondary outcome of 'Adverse effects'.We were unable to combine any of our results because of variability in the interventions and paucity of data.

AUTHORS' CONCLUSIONS

We were unable to determine clear implications to inform clinical practice from the very low-quality evidence currently available. The modest treatment responses reported were in people with atopic eczema, specifically with sensitivity to one or more aeroallergens. Thus, their use in the eczema population as a whole is unknown. High-quality long-term trials of single, easy-to-administer house dust mite reduction or avoidance measures are worth pursuing.

[Microbiological air quality in some kindergartens and antibiotic resistance of bacteria of the Staphylococcus spp. genus]

BACKGROUND

Microbiological contamination or tne air and the acquisition of the antibiotic resistance by pathogenic bacteria is a growing phenomenon that has a substantial impact on the quality of our health. This problem applies mainly to public areas where we spend a large part of our lives. This study was focused on the microbiological analysis of the air in some kindergartens and antibiotic resistance of bacteria of the Stephylococcus spp. genus. The identification of the isolated mould fungi has been also made.

MATERIAL AND METHODS

Air samples were collected from classrooms in the seasonal cycle in the mornings and afternoons using 2 methods, sedimentation and impact. Air samples collected outside the kindergartens served as controls. Air quality assessments were based on the groups of indicator microorganisms, according to Polish standards. The susceptibility of isolated staphylococci was assessed with the disc-diffusion method, using 8 different classes of antibiotics, in line with the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST).

RESULTS

The analyses show that, regardless of the method, the total number of heterothropic bacteria and staphylococci in the air of the analyzed kindergartens exceeded the allowable limits. There was no air-pollution with the fungal infection. Based on the antibiogram, it was found that Staphylococcus spp. strains showed the highest sensitivity to chloramphenicol and the lowest to penicillin and gentamicin. Among the fungi moulds of the genus Cladosporium predominated.

CONCLUSIONS

The results of the analyses highlight the need for regular health checks and further research to help identify biological factors that may significantly affect the quality of health of people living in public spaces.

Genetically engineered Lactococcus lactis protect against house dust mite allergy in a BALB/c mouse model

Background

Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model.

Methods

Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall) were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro.

Results

Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes.

Conclusion

Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance.

Modern approaches to therapeutic vaccination as treatment for Type 1 respiratory hypersensitivity (allergy) treatment

The incidence of respiratory and other allergies has increased dramatically in many countries over the last few decades. Drug treatment is symptomatic and has a minimal effect on the underlying immunological dysfunction. This disease process may, however, be modified by allergy vaccination, which is typically applied by injecting increasing strengths of the offending allergens. Its use has been fairly limited owing to long injection schedules involving many visits to the physician, occasional local or systemic side effects, perceived limited efficacy and poor compliance. A greater understanding of the immunological mechanisms involved in allergy vaccination has led recently to the development of new generations of products with properties that address some of these issues, and these advances are likely to increase the successful use of the therapy.

Laboratory animals and respiratory allergies: the prevalence of allergies among laboratory animal workers and the need for prophylaxis

OBJECTIVE

Subjects exposed to laboratory animals are at a heightened risk of developing respiratory and allergic diseases. These diseases can be prevented by simple measures such as the use of personal protective equipment. We report here the primary findings of the Laboratory Animals and Respiratory Allergies Study regarding the prevalence of allergic diseases among laboratory animal workers, the routine use of preventive measures in laboratories and animal facilities, and the need for prevention programs.

METHODS

Animal handlers and non-animal handlers from 2 Brazilian universities (University of São Paulo and State University of Campinas) answered specific questionnaires to assess work conditions and symptoms. These subjects also underwent spirometry, a bronchial challenge test with mannitol, and skin prick tests for 11 common allergens and 5 occupational allergens (rat, mouse, guinea pig, hamster, and rabbit).

RESULTS

Four hundred fifty-five animal handlers (32±10 years old [mean±SD], 209 men) and 387 non-animal handlers (33±11 years old, 121 men) were evaluated. Sensitization to occupational allergens was higher among animal handlers (16%) than non-animal handlers (3%, p<0.01). Accessibility to personal protective equipment was measured at 85% (median, considering 73 workplaces of the animal handler group). Nineteen percent of the animal handlers indicated that they wear a respirator at all times while handling animals or working in the animal room, and only 25% of the animal handlers had received an orientation about animal-induced allergies, asthma, or rhinitis.

CONCLUSION

In conclusion, our data indicate that preventive programs are necessary. We suggest providing individual advice to workers associated with institutional programs to promote a safer work environment.

Ankaflavin, a novel Nrf-2 activator for attenuating allergic airway inflammation

The role of inflammation-induced oxidative stress in the pathogenesis and progression of chronic inflammatory airways diseases has received increasing attention in recent years. Nuclear factor-erythroid 2 related factor 2 (Nrf-2) is the primary transcription factor that regulates the expression of antioxidant and detoxifying enzymes. In this study, yellow pigment ankaflavin (AK), derived from Monascus-fermented products, elevated nuclear Nrf-2 protein translocation in both the A549 lung cell line and the lungs of ovalbumin (OVA)-challenged mice. Furthermore, AK increased the mRNA expression of antioxidant enzymes regulated by Nrf-2, leading to a reduction in allergen-driven airway inflammation, mucus cell hyperplasia, and eosinophilia in OVA-challenged mice. Additionally, AK prevented T-cell infiltration and Th2 cytokines including interleukin (IL)-4, IL-5, and IL-13 generation in bronchial alveolar lavage fluid. The adhesion molecules ICAM-1, VCAM-1, and eotaxin were substantially reduced by AK treatment. Importantly, the inhibitory effect of AK on adhesion molecule production and immune cell infiltration was abolished by Nrf-2 small interfering RNA. This is the first study to illustrate that AK acts as a novel Nrf-2 activator for modulating the oxidative stress pathway to improve the lung injury and ameliorate the development of airway inflammation.

Fetal origins of asthma

There is convincing evidence that asthma has its origins in early life. We review the epidemiological and biological evidence for fetal exposures that may have a causal role in asthma development. However, those factors that provoke asthma exacerbations are not necessarily the same as those associated with disease induction. Epidemiological studies have identified many potential exposures linked to asthma but these do not confirm causality and have not been replicated by experiment. Asthma is a heterogeneous disease and there are developmental influences on at least two pathways, airway structure and airway inflammation. The fetus is not immunologically naive and intrauterine exposures can act directly to invoke immunological sensitisation leading postnatally to airway inflammation. Other potential mechanisms include indirect effects on airway and lung growth through fetal nutrition and epigenetic modifications of DNA expression by environmental exposures. Identifying the causal factors will provide the targets for interventions to prevent disease.

Prevention and treatment of DNA vaccine encoding cockroach allergen Bla g 1 in a mouse model of allergic airway inflammation

BACKGROUND

One-fourth of the US population is sensitized to the German cockroach. Primary German cockroach allergen Bla g 1 is detected in 63% of homes and 52% of childcare facilities in the United States. No effective treatment or vaccination strategies are yet available.

OBJECTIVES

We evaluated the prophylactic and therapeutic efficacy of a plasmid DNA-mediated vaccination using the Bla g 1 gene in a mouse model of allergic inflammatory airway disease.

METHODS

A plasmid DNA vector coding for the Bla g 1 allergen controlled by cytomegalovirus promoter was constructed. To estimate the protective efficacy, BALB/c mice were given three injections of plasmid DNA-Bla g 1 prior to sensitization with two priming doses of recombinant Bla g 1 (rBla g 1) antigens, followed by nebulized rBla g 1 challenge. In the therapeutic approach, sensitization was followed by administering Bla g 1 DNA vaccine.

RESULTS

Bla g 1 vaccination significantly reduced allergen-induced airway inflammation, even after mice were presensitized and a Th2-dominant response was established. The Bla g 1 vaccination significantly reduced total inflammatory cell infiltrate, eosinophilia, secretion of Th2 cytokines IL-4 and IL-5 in bronchoalveolar lavage fluid, allergen-induced inflammatory infiltrates in the lungs, and Bla g 1-specific IgE in serum upon challenge with rBla g 1. Importantly, Bla g 1 DNA vaccination was able to induce IL-10-secreting regulatory T cells that could suppress the allergen-specific Th2 cells.

CONCLUSION

DNA vaccination showed protective and therapeutic efficacy against a clinically relevant allergen Bla g 1.

[Effect of large-scale repair work on indoor formaldehyde levels upon and subjective symptoms in, medical students during gross anatomy dissection course]

OBJECTIVES

To examine the effect of large-scale repair work on indoor formaldehyde (FA) levels and subjective symptoms in medical students during a gross anatomy dissection course.

METHODS

We measured the indoor FA levels, room air temperature, and room humidity during a gross anatomy dissection course. In addition, the prevalence of subjective symptoms, keeping allergy state, and wearing personal protective equipment were surveyed in two groups of students using a self-administered questionnaire.

RESULTS

The mean indoor FA levels before and after repair work were 1.22 ppm and 0.14 ppm, respectively. The mean indoor FA level significantly decreased after repair work. The prevalences of most subjective symptoms before the anatomy practice were similar before and after the repair work. However, the prevalences of most subjective symptoms during the anatomy practice were lower after the repair work.

CONCLUSIONS

The mean indoor FA levels and prevalences of subjective symptoms decreased after the repair work. We have to continuously monitor indoor FA levels, carry out private countermeasures to minimize exposure to FA, and maintain equipment for ventilation to be able to conduct practice in a comfortable environment.

[Harmful biological agents at museum workposts]

BACKGROUND

The aim of the studies was to determine the level and kind of microbiological contamination of air and surfaces in museum premises with various collection specificities. In addition, the criteria for selecting indicators of contamination with harmful biological agents at museum workposts are proposed.

MATERIAL AND METHODS

The analysis of microbial contamination was carried out in 14 museum premises (storehouses, restoration workshops, exhibition hall). Microbiological air purity was measured with a MAS-100 Eco Air Sampler. Surface samples were collected using contact plates RODAC Envirocheck. Biochemical API tests were used to identify bacteria and yeasts. Fungi were diagnosed with taxonomic keys, based on macro- and microscopic mycelia assessment.

RESULTS

The levels of microbiological contamination in museums varied and ranged from 2.1 x 10(2) to 7.0 x 10(3) cfu/m3 in the air and from 1.4 x 10(2) to 1.7 x 10(4) cfu/100 cm2 on surfaces. The dominant microorganisms were fungi, which accounted respectively for 18-98% and 23-100% of all isolates from tested sites and surfaces. It was found that the amount of fungi in the indoor air of the Museum of Archeology and Ethnography and the Museum of Independence Traditions equaled respectively 4.2 x 10(2) cfu/m3 and 1.4 x 10(4) cfu/m3, which means that they exceeded the recommended reference value of 2.0 x 10(2) cfu/m3.

CONCLUSIONS

Having analyzed the frequency of strain isolation, the source of microorganisms and the hazard to human health, 10 fungal species were isolated, which may be regarded as indicators of contamination with harmful biological agents at museum workposts. They are: Aspergillus (A. niger, A. versicolor), Cladosporium (C. herbarum, C. macrocarpum), Penicillium (P. carneum, P. digitatum, P. italicum, P. paneum, P. polonicum), Rhizopus nigricans.

Fungal aerosol in the process of poultry breeding--quantitative and qualitative analysis

BACKGROUND

The aim of this study was to assess fungal air contamination in the processes associated with poultry breeding depending on the season. The evaluation was based on the determined concentrations of fungi and qualitative identification of isolated microorganisms.

MATERIALS AND METHODS

The study covered 2 hatcheries and 3 hen buildings. The air was sampled in spring, summer and autumn directly onto a filter using air aspirator. For the quantitative analysis of fungi, the medium MEA with chloramphenicol and streptomycin was used. The qualitative identification of fungi was carried out based on macro- and microscopic analysis.

RESULTS

The concentrations of total airborne mesophilic fungi in breeding facilities ranged from 1.22 x 10(3) to 5.87 x 10(5) cfu/m3 with the arithmetic mean value 1.60 x 10(5) cfu/m5. In 45% of the taken samples, these levels exceeded the reference value recommended in Poland for occupational environment exposure. The fungi concentration in the air of poultry houses was significantly modified by season (p = 0.04). A higher concentration of fungi occurred in autumn (p = 0.05). The dominant fungal microflora in the air was composed of molds (88%), with the most prevalent genus Acremonium. Yeasts constituted another 10% of bioaerosol and were mainly represented by genus Candida. The fungal aerosol contained two species qualified to the 2 group of risk--Aspergillus fumigatus and Candida tropicalis.

CONCLUSIONS

Facilities of poultry farms are contaminated with high concentrations of fungal aerosols, especially in a colder season, often exceeding the recommended limits. Among the fungi, there are also present pathogenic microorganisms that may pose a risk to farm workers' health.

EAACI position paper: prevention of work-related respiratory allergies among pre-apprentices or apprentices and young workers

Apprenticeship is a period of increased risk of developing work-related respiratory allergic diseases. There is a need for documents to provide appropriate professional advice to young adults aiming to reduce unsuitable job choices and prevent impairment from their careers. The present document is the result of a consensus reached by a panel of experts from European and non-European countries addressed to allergologists, pneumologists, occupational physicians, primary care physicians, and other specialists interested in this field, which aims to reduce work-related respiratory allergies (rhinoconjunctivitis and asthma) among allergic or nonallergic apprentices and other young adults entering the workforce. The main objective of the document is to issue consensus suggestions for good clinical practice based on existing scientific evidence and the expertise of a panel of physicians.

Prevention of house dust mite induced allergic airways disease in mice through immune tolerance

Allergic airways disease is a consequence of a Th2 response to an allergen leading to a series of manifestations such as production of allergen-specific IgE, inflammatory infiltrates in the airways, and airway hyper-reactivity (AHR). Several strategies have been reported for tolerance induction to allergens leading to protection from allergic airways disease. We now show that CD4 blockade at the time of house dust mite sensitization induces antigen-specific tolerance in mice. Tolerance induction is robust enough to be effective in pre-sensitized animals, even in those where AHR was pre-established. Tolerant mice are protected from airways eosinophilia, Th2 lung infiltration, and AHR. Furthermore, anti-CD4 treated mice remain immune competent to mount immune responses, including Th2, to unrelated antigens. Our findings, therefore, describe a strategy for tolerance induction potentially applicable to other immunogenic proteins besides allergens.

Panax ginseng ameliorates airway inflammation in an ovalbumin-sensitized mouse allergic asthma model

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng (PG) is a medicinal herb that has been used to treat various immune diseases including asthma and COPD. In this study, we investigated the inhibitory mechanism of PG on asthma parameters in mice.

MATERIALS AND METHODS

BALB/c mice were sensitized with 20 μg/200 μl OVA adsorbed on 1.0mg/50 μl aluminum hydroxide gel adjuvant by i.p. injection on days 0 and 14. Mice were then challenged with 5% OVA in PBS to the nose for 30 min once a day for 3 days, from day 20 until day 22, using a nebulizer. PG (20mg/kg) or vehicle was administrated by i.p. injection once a day 10 min before every OVA challenge for 3 days. The recruitment of inflammatory cells into bronchoalveolar lavage fluid or lung tissues was measured. The expression of EMBP, Muc5ac, CD40, and CD40 ligand (CD40L) in lung tissues was investigated. In addition, the cytokines and mitogen activated protein (MAP) kinases were measured by RT-PCR and Western blot.

RESULTS AND CONCLUSIONS

PG restored the expression of EMBP, Muc5ac, CD40, and CD40L, as well as the mRNA and protein levels of interleukin (IL)-1β, IL-4, IL-5, and tumor necrosis factor (TNF)-α. In addition, PG inhibited the numbers of goblet cells and further small G proteins and MAP kinases in bronchoalveolar lavage cells and lung tissues increased in ovalbumin-induced allergic asthma in mice. These results suggest that PG may be used as a therapeutic agent in asthma, based on reductions of various allergic responses.

[The Bergamo experience of health surveillance in the bakery sector]

The purpose of this study is to analyse the various risk factors present in the artisan and semi industrial bread making technological cycle as well as verify the kind of illnesses and ailments encountered amongst the workforce. The objective being to identify a preventive action programme together with the necessary Health support measures. Our case study, drew upon a sample of 428 workers (252 bread makers and 176 sales staff). Each of them was asked to complete a questionnaire about the production process, the kind of exposure to wheat flour particles, smoking habits, present or past common allergy pathologies, the symptoms connected to the work, both in the allergic and osteomuscular field. Those positive respondents were subjected to various medical tests so as to ascertain a definitive diagnosis of their ailments. As was easy to predict, the most common pathology (ailment), found amongst bread makers, related to the respiratory system--16.7% of the population. In particular, 7.5% was affected by eye rhinitis, 2.8% by allergic bronchial asthma, 3.2% indicated a mix between rhinitis and bronchial asthma and 3.2% by BPCO. Skin ailments affected 2% of workers and WMSDs more than 2.8%.

[Evaluation of occupational allergic diseases of the respiratory tract]

The paper presents the basic etiological and pathogenetic aspects of occupational allergic diseases of the respiratory tract, discusses the clinical course, diagnosis, and priorities of the prevention of allergic diseases of the upper airways and bronchopulmonary apparatus from the action of industrial allergens.

[Etiology, determinants, diagnostics and prophylaxis of occupational allergic respiratory diseases in hairdressers]

Hairdressers are occupationally exposed to many substances both, allergizing and irritating. The continuous development of hairdressing services brings about new risks. The most important allergens are: persulfates (ammonium and potassium), paraphenylenediamine, and latex. A growing number of occupational allergens in the work environment of hairdresses, providing that most of them are low weight allergens, may cause some diagnostic problems. Health risks related with haidressing occupation, have prompted the researchers to pay more attention to risk factors of occupational allergy. Owing to the fact, that first morbid symptoms may occur very early, even during the apprenticeship in a hairdressing school, it is very important to indentify health risks, which can be useful in predicting the onset of occupational allergy and in developing effective prevention methods. The most common allergens at the hairdressers' workplace, risk factors, diagnostics of occupational asthma and rhinitis, as well as the prevention of these diseases are reviewed in this publication.

Long-lasting effects of sublingual immunotherapy according to its duration: a 15-year prospective study

BACKGROUND

Data on the long-term effects of sublingual immunotherapy (SLIT) are sparse, and the optimal duration of treatment is a matter of debate.

OBJECTIVE

We sought to prospectively evaluate the long-term effect of SLIT given for 3, 4, or 5 years and to compare the effect of those different durations.

METHODS

In this prospective open controlled study we followed up patients with respiratory allergy who were monosensitized to mites for 15 years. The subjects were divided in 4 groups receiving drug therapy alone or SLIT for 3, 4, or 5 years. Clinical scores, skin sensitizations, methacholine reactivity, and nasal eosinophil counts were evaluated every year during the winter months. The clinical effect was considered to persist until clinical scores remained at less than 50% of the baseline value, and then patients underwent another course of SLIT.

RESULTS

Seventy-eight patients were enrolled, and 59 completed the study. In the 12 control subjects no relevant change in clinical scores was seen throughout the study. In the patients receiving SLIT for 3 years, the clinical benefit persisted for 7 years. In those receiving immunotherapy for 4 or 5 years, the clinical benefit persisted for 8 years. New sensitizations occurred in all the control subjects over 15 years and in less than a quarter of the patients receiving SLIT (21%, 12%, and 11%, respectively). The second course of vaccination induced a benefit more rapidly than the first course. The behavior of bronchial hyperreactivity and nasal eosinophils paralleled the clinical score.

CONCLUSION

Under the present conditions, it can be suggested that a 4-year duration of SLIT is the optimal choice because it induces a long-lasting clinical improvement similar to that seen with a 5-year course and greater than that of a 3-year vaccination.

Montelukast during primary infection prevents airway hyperresponsiveness and inflammation after reinfection with respiratory syncytial virus

RATIONALE

Respiratory syncytial virus (RSV) bronchiolitis in infants may be followed by the development of asthma-like symptoms. Age at first infection dictates consequences upon reinfection. Reinfection of mice initially exposed as neonates to RSV enhanced development of airway hyperresponsiveness (AHR), eosinophilic inflammation, and mucus hyperproduction. RSV lower respiratory tract disease is associated with activation of the leukotriene pathway.

OBJECTIVES

To determine the effects of montelukast (MK), a cysteinyl leukotriene (cysLT) receptor antagonist, in primary and secondary RSV-infected newborn and adult mice.

METHODS

BALB/c mice were infected with RSV at 1 week (neonate) or 6 to 8 weeks (adult) of age and reinfected 5 weeks later. MK was administered 1 day before the initial infection and through Day 6 after infection. Seven days after primary or secondary infection, airway function was assessed by lung resistance to increasing doses of inhaled methacholine; lung inflammation, goblet cell metaplasia, and cytokine levels in bronchoalveolar lavage fluid were monitored.

MEASUREMENTS AND MAIN RESULTS

RSV infection induced cysLT release in bronchoalveolar lavage fluid. MK decreased RSV-induced AHR, airway inflammation, and increased IFN-gamma production in primary infected adult and neonatal mice. MK, administered during initial infection of neonates but not during secondary infection, prevented subsequent enhancement of AHR, airway eosinophilia, and mucus hyperproduction upon reinfection.

CONCLUSIONS

MK attenuated the initial responses to primary RSV infection in both age groups and altered the consequences of RSV reinfection in mice initially infected as neonates. These data support an important role for cysLT in RSV-induced AHR and inflammation.

Effect of ozone on response to ovalbumin & its modulation by vitamins C & E in sensitized guinea pigs

BACKGROUND & OBJECTIVES

Exposure to ozone and asthma are both associated with increased oxidative stress. Exposure to ozone therefore, may potentiate the airway response to allergens. We undertook this study to investigate the effect of ozone exposure on airway response to ovalbumin in sensitized guinea pigs and its modulation by dietary supplementation with antioxidant vitamins C and E.

METHODS

After in vivo measurements of specific airways conductance (SGaw) and airway hyperresponsiveness (AHR) to inhaled histamine, guinea pigs were sensitized to ovalbumin and divided into three groups: (i) sensitized; (ii) sensitized and exposed daily to ozone; and (iii) sensitized, exposed daily to ozone and given dietary supplementation with vitamin C, 2 mg/kg body wt and E, 7 IU/kg body wt. A control group of nonsensitized animals was included. After 4 wk, AHR was measured again and animals were challenged with inhaled ovalbumin. Changes in SGaw were followed for early and late airway bronchoconstrictive responses. The following measurements were obtained: (i) parameters of oxidative stress--plasma malonaldehyde (MDA) as marker of lipid peroxidation and superoxide anion generation by leukocytes and bronchoalveolar lavage (BAL) cells; (ii) antioxidant status: red cell superoxide dismutase (SOD); and (iii) glutathione peroxidase (GPx). BAL cytology was studied.

RESULTS

Ozone exposure resulted in an increase in AHR and early and late bronchoconstrictive responses after ovalbumin challenge, greater superoxide anion generation in BAL cells, higher plasma MDA levels and decrease in red cell SOD activity. Dietary supplementation with vitamin C and E prevented or ameliorated these responses.

INTERPRETATION & CONCLUSIONS

Exposure to ozone at concentrations of 0.12 ppm for 2 h daily for 4 wk enhances the airway response to allergens in sensitized guinea pigs. Dietary supplementation with antioxidant vitamins E and C, affords variable degree of protection against this enhancement.