Allergic sensitization and exposure to ambient air pollution beginning early in life lead to a COPD-like phenotype in young adult mice.

The perinatal period and early infancy are considered critical periods for lung development. During this period, adversities such as environmental exposures, allergic sensitization, and asthma are believed to impact lung health in adulthood. Therefore, we hypothesized that concomitant exposure to allergic sensitization and urban-derived fine particulate matter (PM2.5) in the early postnatal period of mice would cause more profound alterations in lung alveolarization and growth and differently modulate lung inflammation and gene expression than either insult alone in adult life. BALB/c mice were sensitized with ovalbumin (OVA) and exposed to PM2.5 from the fifth day of life. Then, we assessed lung responsiveness, inflammation in BALF, lung tissue, and alveolarization by stereology. In addition, we performed a transcriptomic analysis of lung tissue on the 40th day of life. Our results showed that young adult mice submitted to allergic sensitization and exposure to ambient PM2.5 since early life presented decreased lung growth with impaired alveolarization, a mixed neutrophilic-eosinophilic pattern of lung inflammation, increased airway responsiveness, and increased expression of genes linked to neutrophil recruitment when compared to animals that were OVA-sensitized or PM2.5 exposed only. Both, early life allergic sensitization and PM2.5 exposure, induced inflammation and impaired lung growth, but concomitant exposure was associated with worsened inflammation parameters and caused alveolar enlargement. Our experimental data provide pathological support for the hypothesis that allergic or environmental insults in early life have permanent adverse consequences for lung growth. In addition, combined insults were associated with the development of a COPD-like phenotype in young adult mice. Together with our data, current evidence points to the urgent need for healthier environments with fewer childhood disadvantage factors during the critical windows of lung development and growth.

Effects of VAChT reduction and α7nAChR stimulation by PNU-282987 in lung inflammation in a model of chronic allergic airway inflammation.

The cholinergic anti-inflammatory pathway has been shown to regulate lung inflammation and cytokine release in acute models of inflammation, mainly via α7 nicotinic receptor (α7nAChR). We aimed to evaluate the role of endogenous acetylcholine in chronic allergic airway inflammation in mice and the effects of therapeutic nAChR stimulation in this model. We first evaluated lung inflammation and remodeling on knock-down mice with 65% of vesicular acetylcholine transport (VAChT) gene reduction (KDVAChT) and wild-type(WT) controls that were subcutaneously sensitized and then inhaled with ovalbumin(OVA). We then evaluated the effects of PNU-282987(0.5-to-2mg/kg),(α7nAChR agonist) treatment in BALB/c male mice intraperitoneal sensitized and then inhaled with OVA. Another OVA-sensitized-group was treated with PNU-282987 plus Methyllycaconitine (MLA,1 mg/kg, α7nAChR antagonist) to confirm that the effects observed by PNU were due to α7nAChR. We showed that KDVAChT-OVA mice exhibit exacerbated airway inflammation when compared to WT-OVA mice. In BALB/c, PNU-282987 treatment reduced the number of eosinophils in the blood, BAL fluid, and around airways, and also decreased pulmonary levels of IL-4,IL-13,IL-17, and IgE in the serum of OVA-exposed mice. MLA pre-treatment abolished all the effects of PNU-282987. Additionally, we showed that PNU-282987 inhibited STAT3-phosphorylation and reduced SOCS3 expression in the lung. These data indicate that endogenous cholinergic tone is important to control allergic airway inflammation in a murine model. Moreover, α7nAChR is involved in the control of eosinophilic inflammation and airway remodeling, possibly via inhibition of STAT3/SOCS3 pathways. Together these data suggest that cholinergic anti-inflammatory system mainly α7nAChR should be further considered as a therapeutic target in asthma.

Vesicular acetylcholine transport deficiency potentiates some inflammatory responses induced by diesel exhaust particles.

Endogenous acetylcholine (ACh), which depends of the levels of vesicular ACh transport (VAChT) to be released, is the central mediator of the cholinergic anti-inflammatory system. ACh controls the release of cytokine in different models of inflammation. Diesel exhaust particles (DEP) are one of the major environmental pollutants produced in large quantity by automotive engines in urban center. DEP bind the lung parenchyma and induce inflammation. We evaluated whether cholinergic dysfunction worsens DEP-induced lung inflammation. Male mice with decreased ACh release due to reduced expression of VAChT (VAChT-KD mice) were submitted to DEP exposure for 30 days (3 mg/mL of DEP, once a day, five days a week) or saline. Pulmonary function and inflammation as well as extracellular matrix fiber deposition were evaluated. Additionally, airway and nasal epithelial mucus production were quantified. We found that DEP instillation worsened lung function and increased lung inflammation. Higher levels of mononuclear cells were observed in the peripheral blood of both wild-type (WT) and VAChT-KD mice. Also, both wild-type (WT) and VAChT-KD mice showed an increase in macrophages in bronchoalveolar lavage fluid (BALF) as well as increased expression of IL-4, IL-6, IL-13, TNF-α, and NF-κB in lung cells. The collagen fiber content in alveolar septa was also increased in both genotypes. On the other hand, we observed that granulocytes were increased only in VAChT-KD peripheral blood. Likewise, increased BALF lymphocytes and neutrophils as well as increased elastic fibers in alveolar septa, airway neutral mucus, and nasal epithelia acid mucus were observed only in VAChT-KD mice. The cytokines IL-4 and TNF-α were also higher in VAChT-KD mice compared with WT mice. In conclusion, decreased ability to release ACh exacerbates some of the lung alterations induced by DEP in mice, suggesting that VAChT-KD animals are more vulnerable to the effects of DEP in the lung.

Aerobic Exercise Decreases Lung Inflammation by IgE Decrement in an OVA Mice Model.

Aerobic exercise (AE) reduces lung function decline and risk of exacerbations in asthmatic patients. However, the inflammatory lung response involved in exercise during the sensitization remains unclear. Therefore, we evaluated the effects of exercise for 2 weeks in an experimental model of sensitization and single ovalbumin-challenge. Mice were divided into 4 groups: mice non-sensitized and not submitted to exercise (Sedentary, n=10); mice non-sensitized and submitted to exercise (Exercise, n=10); mice sensitized and exposed to ovalbumin (OVA, n=10); and mice sensitized, submitted to exercise and exposed to OVA (OVA+Exercise, n=10). 24 h after the OVA/saline exposure, we counted inflammatory cells from bronchoalveolar fluid (BALF), lung levels of total IgE, IL-4, IL-5, IL-10 and IL-1ra, measurements of OVA-specific IgG1 and IgE, and VEGF and NOS-2 expression via western blotting. AE reduced cell counts from BALF in the OVA group (p<0.05), total IgE, IL-4 and IL-5 lung levels and OVA-specific IgE and IgG1 titers (p<0.05). There was an increase of NOS-2 expression, IL-10 and IL-1ra lung levels in the OVA groups (p<0.05). Our results showed that AE attenuated the acute lung inflammation, suggesting immunomodulatory properties on the sensitization process in the early phases of antigen presentation in asthma.

Sakuranetin reverses vascular peribronchial and lung parenchyma remodeling in a murine model of chronic allergic pulmonary inflammation.

BACKGROUND AND PURPOSE: Asthma is a disease of high prevalence and morbidity that generates high costs in hospitalization and treatment. Although the airway is involved in the physiopathology of asthma, there is also evidence of the importance of vascular and lung parenchyma inflammation and remodeling, which can contribute to the functional pulmonary alterations observed in asthmatic patients. Our aim was to evaluate treatment using sakuranetin, a flavone isolated from the twigs of Baccharis retusa (Asteraceae), on vascular and lung parenchyma alterations in an experimental murine model of asthma. METHODS: Male BALB/c mice were subjected to a sensitization protocol with ovalbumin for 30days and were treated with or without sakuranetin (20mg/kg/mice) or dexamethasone (5mg/kg/mice); then, the lungs were collected for histopathological analysis. We evaluated extracellular matrix remodeling (collagen and elastic fibers), inflammation (eosinophils and NF-kB) and oxidative stress (8-isoprostane) in the pulmonary vessels and lung parenchyma. The thickness of the vascular wall was quantified, as well as the vascular endothelial growth factor (VEGF) levels. RESULTS: We demonstrated that sakuranetin reduced the number of eosinophils and elastic fibers in both the pulmonary vessels and the lung parenchyma, probably due to a reduction of oxidative stress and of the transcription factor NF-kB and VEGF levels in the lung. In addition, it reduced the thickness of the pulmonary vascular wall. The treatment had no effect on the collagen fibers. In most of the parameters, the effect of sakuranetin was similar to the dexamethasone effect. CONCLUSIONS AND IMPLICATIONS: Sakuranetin had anti-inflammatory and antioxidant effects, preventing vascular and distal parenchyma changes in this experimental model of asthma.

Pulmonary inflammation is regulated by the levels of the vesicular acetylcholine transporter.

Acetylcholine (ACh) plays a crucial role in physiological responses of both the central and the peripheral nervous system. Moreover, ACh was described as an anti-inflammatory mediator involved in the suppression of exacerbated innate response and cytokine release in various organs. However, the specific contributions of endogenous release ACh for inflammatory responses in the lung are not well understood. To address this question we have used mice with reduced levels of the vesicular acetylcholine transporter (VAChT), a protein required for ACh storage in secretory vesicles. VAChT deficiency induced airway inflammation with enhanced TNF-α and IL-4 content, but not IL-6, IL-13 and IL-10 quantified by ELISA. Mice with decreased levels of VAChT presented increased collagen and elastic fibers deposition in airway walls which was consistent with an increase in inflammatory cells positive to MMP-9 and TIMP-1 in the lung. In vivo lung function evaluation showed airway hyperresponsiveness to methacholine in mutant mice. The expression of nuclear factor-kappa B (p65-NF-kB) in lung of VAChT-deficient mice were higher than in wild-type mice, whereas a decreased expression of janus-kinase 2 (JAK2) was observed in the lung of mutant animals. Our findings show the first evidence that cholinergic deficiency impaired lung function and produce local inflammation. Our data supports the notion that cholinergic system modulates airway inflammation by modulation of JAK2 and NF-kB pathway. We proposed that intact cholinergic pathway is necessary to maintain the lung homeostasis.

Comparison of the effects of aerobic conditioning before and after pulmonary allergic inflammation.

The aim of this study is to compare the effects of aerobic conditioning (AC) before (ACBS) and after (ACAS) allergic sensitization. BALB/c mice were divided into two main groups: ACBS and ACAS. Each groups was divided into subgroups: control (nonsensitized/nontrained), AC (nonsensitized/trained), ovalbumin (OVA) (sensitized/nontrained), AC+OVA (trained/sensitized), and OVA+AC (sensitized/trained). Sensitization was induced using OVA and AC performed in treadmill (moderate intensity). We examined IgE and IgG1 levels, eosinophil counting, expression of Th1 (interleukin (IL)-2, IFN-α) and Th2 cytokines (IL-4, IL-5, IL-13), IL-10, vascular endothelial growth factor (VEGF), and airway remodeling. IgE and IgG1 were decreased only when exercise was performed before sensitization (ACBS); however, there was a decrease of eosinophils, Th2 cytokines, VEGF, and airway remodeling and increase in IL-10 in either ACBS or ACAS groups. Our results demonstrate that aerobic conditioning reduces Th2 response before and after sensitization by increasing IL-10 while the production of anaphylactic antibodies is reduced only when exercise is performed before sensitization.

Tolerogenic microenvironment in neonatal period induced by maternal immunization with ovalbumin.

Maternal immunization with allergens, such as ovalbumin (OVA), can inhibit the development of an allergic response in offspring. The regulatory mechanisms seem to be mediated by maternal antibodies (MatAbs) and factors generated by the maternal-fetal interface. The aim of this study was to verify the pathways of inhibitory Ab transference after maternal immunization with OVA and the effect of the offspring's dendritic cells (DCs) on the generation of regulatory T (Treg) cells. We verified that preconceptional OVA immunization induces high levels of proinflammatory and regulatory cytokines in the amniotic fluid, allowing the transference of high levels of anti-OVA IgG1 Abs to the offspring. Using an adoptive nursing protocol, we verified that maternal immunization leads to MatAb transference by the placental route and by breastfeeding contribute to the inhibition of anaphylactic IgE and IgG1 Ab responses in immunized offspring. We observed that maternal immunization decreased eosinophil numbers in recovered bronchoalveolar lavage fluid and in the lung tissue, whereas with a lack of control of airway responsiveness to methacholine. Maternal immunization induced in young offspring a decreased percentage of CD11c+ DCs expressing MHC class II and CD40 molecules. Moreover, DCs from both groups of offspring when pulsed with OVA, were able to induce Treg cells in vitro. Similarly, OVA immunization at the neonatal stage increased the frequency of Treg cells, regardless of the mother's immunization status. These findings emphasize that maternal immunization leads to a complex interaction of regulatory factors, with MatAbs, DCs and Treg cells affecting the tolerance of offspring during an allergic response.

Rho-kinase inhibition attenuates airway responsiveness, inflammation, matrix remodeling, and oxidative stress activation induced by chronic inflammation.

Several studies have demonstrated the importance of Rho-kinase in the modulation of smooth muscle contraction, airway hyperresponsiveness, and inflammation. However, the effects of repeated treatment with a specific inhibitor of this pathway have not been previously investigated. We evaluated the effects of repeated treatment with Y-27632, a highly selective Rho-kinase inhibitor, on airway hyperresponsiveness, oxidative stress activation, extracellular matrix remodeling, eosinophilic inflammation, and cytokine expression in an animal model of chronic airway inflammation. Guinea pigs were subjected to seven ovalbumin or saline exposures. The treatment with Y-27632 (1 mM) started at the fifth inhalation. Seventy-two hours after the seventh inhalation, the animals' pulmonary mechanics were evaluated, and exhaled nitric oxide (E(NO)) was collected. The lungs were removed, and histological analysis was performed using morphometry. Treatment with Y-27632 in sensitized animals reduced E(NO) concentrations, maximal responses of resistance, elastance of the respiratory system, eosinophil counts, collagen and elastic fiber contents, the numbers of cells positive for IL-2, IL-4, IL-5, IL-13, inducible nitric oxide synthase, matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, transforming growth factor-ß, NF-κB, IFN-γ, and 8-iso-prostaglandin F2α contents compared with the untreated group (P < 0.05). We observed positive correlations among the functional responses and inflammation, remodeling, and oxidative stress pathway activation markers evaluated. In conclusion, Rho-kinase pathway activation contributes to the potentiation of the hyperresponsiveness, inflammation, the extracellular matrix remodeling process, and oxidative stress activation. These results suggest that Rho-kinase inhibitors represent potential pharmacological tools for the control of asthma.

Effects of aerobic exercise on chronic allergic airway inflammation and remodeling in guinea pigs.

We evaluated the effects of aerobic exercise (AE) on airway inflammation, exhaled nitric oxide levels (ENO), airway remodeling, and the expression of Th1, Th2 and regulatory cytokines in a guinea pig asthma model. Animals were divided into 4 groups: non-trained and non-sensitized (C), non-sensitized and AE (AE), ovalbumin-sensitized and non-trained (OVA), and OVA-sensitized and AE (OVA+AE). OVA inhalation was performed for 8 weeks, and AE was conducted for 6 weeks beginning in the 3rd week of OVA sensitization. Compared to the other groups, the OVA+AE group had a reduced density of eosinophils and lymphocytes, reduced expression of interleukin (IL)-4 and IL-13 and an increase in epithelium thickness (p<0.05). AE did not modify airway remodeling or ENO in the sensitized groups (p>0.05). Neither OVA nor AE resulted in differences in the expression of IL-2, IFN-γ, IL-10 or IL1-ra. Our results show that AE reduces the expression of Th2 cytokines and allergic airway inflammation and induces epithelium remodeling in sensitized guinea pigs.

Inflammation and remodeling in infantile, juvenile, and adult allergic sensitized mice.

BACKGROUND: Airway structural changes occur early in childhood asthma, but it is unknown whether the development of airway alterations in children is similar to that of adults. We compared inflammation and remodeling parameters in allergic sensitized infantile, juvenile, and adult mice. METHODS: Infantile mice (18D) were sensitized with three intraperitoneal injections (i.p.) of ovalbumin (OVA) at days 5 and 7 and challenged with OVA at days 14-16. The 18D1 group received an additional challenge at days 9-11. The juvenile mice (40D) received challenges at days 22-24 and 36-38. Adult mice (100D) were sensitized at days 60-62 and received three inhalations at days 77-79 and 96-98. Animals were submitted to whole body plethysmography. Airway eosinophils, CD3+ T-lymphocytes, IL-5+ cells, mucus content, collagen and reticular fibers density, and smooth muscle thickness were quantified. RESULTS: All sensitized animals presented with airway hyperresponsiveness, without differences in eosinophil cell density. The density of CD3+ T-cells was higher in the 100D and 18D1 groups than in the 18D and 40D groups. Infantile sensitized groups demonstrated increased interleukin-5 expression in the airways. Infantile mice demonstrated more mucus in the bronchiolar epithelium than the 40D and 100D mice. The 18D animals demonstrated less collagen than the 18D1 group. Juvenile and adult mice had increased airway smooth muscle thickness when compared to age-matched controls, but no differences were observed in the infantile groups. CONCLUSION: We have shown that infantile mice develop inflammatory and structural alterations in the airways that are partially different from those developed in older animals.

Eosinophilic pneumonitis induced by aerosol-administered diesel oil and pyrethrum to mice.

OBJECTIVE: To confirm the episode of eosinophilic pneumonitis that occurred in March 2001 in Manaus, Amazon, northern Brazil, as secondary to home aerosolization with 2% cypermethrin diluted in diesel compared with the more conventional 1% cypermethrin and soybean solution used in prophylaxis of dengue. METHODS: Four groups of Swiss mice were kept in polycarbonate cages aerosolized with one of the following solutions: diesel, diesel and cypermethrin, soy oil and cypermethrin, and saline. Three and 6 days after exposure, resistance and compliance of the respiratory system and white cell kinetics in peripheral blood and lung tissue were analyzed. RESULTS: The group exposed to diesel and cypermethrin showed higher respiratory system resistance (p < 0.001), lower compliance (p = 0.03), and increased eosinophils in blood (p = 0.03) and lung tissue (p = 0.005) compared with the other groups. There was an increase of neutrophils in the blood of all experimental groups on the third day after exposure (p < 0.001). CONCLUSIONS: We concluded that diesel associated with cypermethrin induced lung hyperresponsiveness in this experimental model and was associated with increased polymorphonuclear cells (eosinophils and neutrophils) in blood and lungs. This effect is strongest on the third day after exposure. These results are similar to the episode that occurred in Manaus in 2001 and suggest that diesel plus cypermethrin home aerosolization for arbovirosis prophylaxis should be revised.

Eosinophilic pneumonitis induced by aerosol-administered diesel oil and pyrethrum to mice / Neumonía eosinofílica inducida por aerosol de aceite diésel y piretroide en ratones

OBJECTIVE: To confirm the episode of eosinophilic pneumonitis that occurred in March 2001 in Manaus, Amazon, northern Brazil, as secondary to home aerosolization with 2 percent cypermethrin diluted in diesel compared with the more conventional 1 percent cypermethrin and soybean solution used in prophylaxis of dengue. METHODS: Four groups of Swiss mice were kept in polycarbonate cages aerosolized with one of the following solutions: diesel, diesel and cypermethrin, soy oil and cypermethrin, and saline. Three and 6 days after exposure, resistance and compliance of the respiratory system and white cell kinetics in peripheral blood and lung tissue were analyzed. RESULTS: The group exposed to diesel and cypermethrin showed higher respiratory system resistance (p < 0.001), lower compliance (p = 0.03), and increased eosinophils in blood (p = 0.03) and lung tissue (p = 0.005) compared with the other groups. There was an increase of neutrophils in the blood of all experimental groups on the third day after exposure (p < 0.001). CONCLUSIONS: We concluded that diesel associated with cypermethrin induced lung hyperresponsiveness in this experimental model and was associated with increased polymorphonuclear cells (eosinophils and neutrophils) in blood and lungs. This effect is strongest on the third day after exposure. These results are similar to the episode that occurred in Manaus in 2001 and suggest that diesel plus cypermethrin home aerosolization for arbovirosis prophylaxis should be revised.

OBJETIVO: Confirmar el episodio de neumonía eosinofílica ocurrido en marzo de 2001 en Manaus, Amazonas, en el norte de Brasil, secundario al uso de aerosol de cipermetrina diluida al 2 por ciento en aceite diésel en las viviendas en comparación con la profilaxis más convencional contra el dengue, basada en cipermetrina al 1 por ciento con aceite de soya. MÉTODOS: Se mantuvieron cuatro grupos de ratones suizos en jaulas de policarbonato y se aplicó aerosol con una de las siguientes soluciones: aceite diésel, aceite diésel y cipermetrina, aceite de soya y cipermetrina, y solución salina. Se analizaron la resistencia y el funcionamiento del sistema respiratorio y la cinética de leucocitos en sangre periférica y tejido pulmonar a los tres y seis días después de la exposición. RESULTADOS: El grupo expuesto a aceite diésel y cipermetrina mostró mayor resistencia del sistema respiratorio (P < 0,001), peor funcionamiento (P = 0,03) y más eosinófilos en sangre (P = 0,03) y tejido pulmonar (P = 0,005) que los otros grupos. Se observó un aumento de neutrófilos en sangre en todos los grupos experimentales al tercer día después de la exposición (P < 0,001). CONCLUSIONES: El aceite diésel con cipermetrina indujo una hiperrespuesta pulmonar en este modelo experimental y se asoció con un aumento en las células polimorfonucleares (eosinófilos y neutrófilos) en sangre y tejido pulmonar. Este efecto es mayor al tercer día después de la exposición. Estos efectos son similares a los observados en el episodio ocurrido en Manaus en 2001 e indican que se debe reevaluar el uso de aerosol de aceite diésel con cipermetrina para la profilaxis de arbovirus en las viviendas.

pcDNA-IL-12 vaccination blocks eosinophilic inflammation but not airway hyperresponsiveness following murine Toxocara canis infection.

We have investigated the effect of pcDNA3-CpG and pcDNA-IL-12, delivered by intradermal gene gun administration, on the blood/lung eosinophilia, airway hyperresponsiveness as well as the immune response in a murine model of toxocariasis. Our results demonstrated that pcDNA-IL-12 but not pcDNA3-CpG vaccination led to a persistent lower blood/bronchoalveolar eosinophilia following Toxocara canis infection, as pcDNA3-CpG led only to an early transient blockage of eosinophil transmigration into bronchoalveolar fluid following T. canis infection. Prominent Type-1 immune response was pointed out as the hallmark of T. canis infection following pcDNA-IL-12 vaccination. Outstanding IFN-gamma/IL-4 ratio besides low levels of IgG1 with subsequent high IgG2a/IgG1 ratio further characterized a Type-1 polarized immunological profile in pcDNA-IL-12-vaccinated animals. Nevertheless, only pcDNA3-CpG was able to prevent airway hyperresponsiveness induced by T. canis infection. The persistent airway hyperresponsiveness observed in pcDNA-IL-12-vaccinated animals demonstrated that the airway constriction involved other immunological mediator than those blocked by pcDNA-IL-12. Together, these data indicated that pcDNA-IL-12 and pcDNA3-CpG vaccines have distinct therapeutic benefits regarding the eosinophilic inflammation/airway hyperresponsiveness triggered by T. canis infection, suggesting their possible use in further combined therapeutic interventions.

Aerobic exercise decreases chronic allergic lung inflammation and airway remodeling in mice.

RATIONALE: Aerobic conditioning improves exercise capacity and decreases symptoms in patients with asthma. However, its benefits in the context of allergic airway inflammation are poorly understood. OBJECTIVES: To evaluate the effects of two intensities of aerobic exercise on airway inflammation and remodeling in a model of chronic allergic lung inflammation. METHODS: Mice were subjected to chronic ovalbumin (OVA) sensitization and to 4 weeks of low (OVA+Low) or moderate (OVA+Mod) exercise training in a treadmill. Airway inflammation and remodeling and expression of helper T-cell type 1 and 2 cytokines were evaluated. MEASUREMENTS AND MAIN RESULTS: OVA-induced allergic airway inflammation and remodeling were characterized by an increase in collagen (288%), elastic fiber (56%), smooth muscle (380%), and epithelial (402%) contents (P < 0.001) when compared with the control group. OVA+Low and OVA+Mod groups presented a decrease in bronchoalveolar lavage fluid eosinophils (respectively, 84 and 75%; P < 0.01) and airway walls (respectively, 94 and 58%; P < 0.001) when compared with the OVA group. OVA+Low and OVA+Mod groups also presented a reduction in the number of peribronchial inflammatory cells expressing IL-4 (respectively, 85 and 75%; P < 0.01) and IL-5 (respectively, 88 and 89%; P < 0.01) when compared with the OVA group. Aerobic conditioning did not change the expression of either IFN-gamma or IL-2 by inflammatory cells or plasma levels of IgE or IgG1. OVA+Low and OVA+Mod groups presented an increase in the expression of IL-10 (P < 0.001). Low and moderate aerobic conditioning also reduced airway remodeling in OVA-sensitized mice when compared with the OVA group. CONCLUSIONS: We concluded that low and moderate aerobic exercise decreases airway inflammation and remodeling in a murine model of asthma.

Creatine supplementation exacerbates allergic lung inflammation and airway remodeling in mice.

Creatine supplement is the most popular nutritional supplement, and has various metabolic functions and sports medicine applications. Creatine supplementation increases muscle mass and can decrease muscular inflammation. Some studies have also suggested a beneficial role of creatine supplementation on chronic pulmonary diseases such as chronic obstructive pulmonary disease and cystic fibrosis. Among athletes, the prevalence of asthma is high, and many of these individuals may be taking creatine. However, the effects of creatine supplementation on chronic pulmonary diseases of allergic origin have not been investigated. In the present study, we analyzed the effects of creatine supplementation on a model of chronic allergic lung inflammation. Thirty-one Balb/c mice were divided into four groups: control, creatine (Cr), ovalbumin (OVA), and OVA+Cr. OVA and OVA+Cr groups were sensitized with intraperitoneal injections of OVA on Days 0, 14, 28, and 42. OVA challenge (OVA 1%) and Cr treatment (0.5 g/kg/d) were initiated on Day 21 and lasted until Day 53. We determined the index of hyperresponsiveness, the serum levels of OVA-specific immunoglobulin (Ig)E and IgG(1), and the total and differential cell counts in bronchoalveolar lavage fluid. We also quantified airway inflammation, and the airway density of IL-4+, IL-5+, IL-2+, IFN-gamma+, and insulin-like growth factor (IGF)-1+ cells, collagen and elastic fibers, and airway smooth muscle thickness. Our results showed that creatine in OVA-sensitized mice increased hyperresponsiveness; eosinophilic inflammation; airway density of IL-4+, IL-5+, and IGF-1 inflammatory cells; airway collagen and elastin content; and smooth muscle thickness. The results show that creatine supplementation exacerbates the lung allergic response to OVA through a T helper cell type 2 pathway and increased IGF-1 expression.

BCG modulation of anaphylactic antibody response, airway inflammation and lung hyperreactivity in genetically selected mouse strains (Selection IV-A).

The effect of Bacillus Calmette-Guérin (BCG) treatment in allergic pulmonary reaction was studied in mice genetically selected accordingly to a High (H-IVA) or Low (L-IVA) antibody responsiveness. Mice were immunized with ovalbumin (OVA) or OVA plus BCG. Two days after nasal antigenic challenge, seric IgE and IgG1 anti-OVA, eosinophils in pulmonary tissue, inflammatory cells in bronchoalveolar lavage and the compliance and conductance of respiratory system were evaluated. H-IVA mice were found more susceptible than L-IVA, and BCG was able to inhibit simultaneously the production of IgE, the bronchopulmonary inflammation and bronchial hyperresponsiveness in these genetically selected mice.

BCG modulation of anaphylactic antibody response, airwayinflammation and lung hyperreactivity in geneticallyselected mouse strains (Selection IV-A)

The effect of Bacillus Calmette–Gue´rin (BCG) treatment in allergic pulmonary reaction was studied in micegenetically selected accordingly to a High (H-IVA) or Low (L-IVA) antibody responsiveness. Mice wereimmunized with ovalbumin (OVA) or OVA plus BCG. Two days after nasal antigenic challenge, seric IgE andIgG1 anti-OVA, eosinophils in pulmonary tissue, inflammatory cells in bronchoalveolar lavage and the complianceand conductance of respiratory system were evaluated. H-IVA mice were found more susceptible than L-IVA, andBCG was able to inhibit simultaneously the production of IgE, the bronchopulmonary inflammation and bronchialhyperresponsiveness in these genetically selected mice.

Lung eosinophilic inflammation and airway hyperreactivity are enhanced by murine anaphylactic, but not nonanaphylactic, IgG1 antibodies.

BACKGROUND: Chronic airway inflammation is a fundamental feature of bronchial asthma, which is characterized by the accumulation and activation of inflammatory cells, such as mast cells and eosinophils, that are tightly regulated by TH2 cytokines and chemokines. Recently, we demonstrated, in a murine model of asthma with immunosuppressed mice reconstituted with antigen-specific IgE or IgG1 antibodies, that IgE, but not IgG1, participates in potentiation of airway inflammation and induction of airway hyperreactivity (AHR). The IgG1 antibody, however, did not elicit passive cutaneous anaphylactic reactions, which was in contrast to IgE. OBJECTIVES: Because 2 types of murine IgG1 have been demonstrated with regard to anaphylactic activity, the present experiments were undertaken to determine the role of anaphylactic and nonanaphylactic IgG1 antibodies in the development of antigen-induced eosinophilia and AHR in this model. METHODS: Dinitrophenyl-conjugated, heat-coagulated hen's egg white was implanted in immunosuppressed mice reconstituted with anaphylactic or nonanaphylactic IgG1. Intratracheal challenge with aggregated dinitrophenyl-ovalbumin was performed on day 14, and lung inflammatory and mechanical parameters were evaluated after 48 hours. RESULTS: Our results demonstrated that reconstitution of immunosuppressed mice with anaphylactic IgG1 antibodies in contrast to nonanaphylactic IgG1 antibodies potentiates their ability to have pulmonary eosinophilic inflammation and AHR. IL-5 and eotaxin levels in bronchoalveolar lavage fluid from anaphylactic IgG1-reconstituted mice were also higher than those in nonanaphylactic IgG1-reconstituted mice. CONCLUSIONS: These results indicate that the anaphylactic property of murine IgG1 molecules is essential for their capacity to enhance lung eosinophilic inflammation and to induce AHR.