Effects of gasoline engine emissions on preexisting allergic airway responses in mice

Gasoline-powered vehicle emissions contribute significantly to ambient air pollution. We hypothesized that exposure to gasoline engine emissions (GEE) may exacerbate preexisting allergic airway responses. Male BALB/c mice were sensitized by injection with ovalbumin (OVA) and then received a 10-min aerosolized OVA challenge. Parallel groups were sham-sensitized with saline. Mice were exposed 6 h/day to air (control, C) or GEE containing particulate matter (PM) at low (L), medium (M), or high (H) concentrations, or to the H level with PM removed by filtration (high-filtered, HF). Immediately after GEE exposure mice received another 10-min aerosol OVA challenge (pre-OVA protocol). In a second (post-OVA) protocol, mice were similarly sensitized but only challenged to OVA before air or GEE exposure. Measurements of airway hyperresponsiveness (AHR), bronchoalveolar lavage (BAL), and blood collection were performed approximately 24 h after the last exposure. In both protocols, M, H, and HF GEE exposure significantly decreased BAL neutrophils from nonsensitized mice but had no significant effect on BAL cells from OVA-sensitized mice. In the pre-OVA protocol, GEE exposure increased OVA-specific IgG(1) but had no effect on BAL interleukin (IL)-2, IL-4, IL-13, or interferon (IFN)-gamma in OVA-sensitized mice. Nonsensitized GEE-exposed mice had increased OVA-specific IgG(2a), IgE, and IL-2, but decreased total IgE. In the post-OVA protocol, GEE exposure reduced BAL IL-4, IL-5, and IFN-gamma in nonsensitized mice but had no effect on sensitized mice. These results suggest acute exposure to the gas-vapor phase of GEE suppressed inflammatory cells and cytokines from nonsensitized mice but did not substantially exacerbate allergic responses.     

Effects of simulated downwind coal combustion emissions on pre-existing allergic airway responses in mice

Context: Coal-fired power plant emissions can contribute a significant portion of the ambient air pollution in many parts of the world.

Objective: We hypothesized that exposure to simulated downwind coal combustion emissions (SDCCE) may exacerbate pre-existing allergic airway responses.

Methods: Mice were sensitized and challenged with ovalbumin (OVA). Parallel groups were sham-sensitized with saline. Mice were exposed 6?h/day for 3 days to air (control, C) or SDCCE containing particulate matter (PM) at low (L; 100 μg/m³), medium (M; 300 μg/m³), or high (H; 1000 μg/m³) concentrations, or to the H level with PM removed by filtration (high-filtered, HF). Immediately after SDCCE exposure, mice received another OVA challenge (pre-OVA protocol). In a second (post-OVA) protocol, mice were similarly sensitized but only challenged to OVA before air/SDCCE. Measurement of airway hyperresponsiveness (AHR), bronchoalveolar lavage (BAL), and blood collection were performed ~24?h after the last exposure.

Results: SDCCE significantly increased BAL macrophages and eosinophils in OVA-sensitized mice from the post-OVA protocol. However, there was no effect of SDCCE on BAL macrophages or eosinophils in OVA-sensitized mice from the pre-OVA protocol. BAL neutrophils were elevated following SDCCE in both protocols in nonsensitized mice. These changes were not altered by filtering out the PM. In the post-OVA protocol, SDCCE decreased OVA-specific IgG₁ in OVA-sensitized mice but increased levels of total IgE, OVA-specific IgE and OVA-specific IgG₁ and IgG_2a in non-sensitized animals. In the pre-OVA protocol, SDCCE increased OVA-specific IgE in both sensitized and non-sensitized animals. Additionally, BAL IL-4, IL-13, and IFN-γ levels were elevated in sensitized mice.

Conclusion: These results suggest that acute exposure to either the particulate or gaseous phase of SDCCE can exacerbate various features of allergic airway responses depending on the timing of exposure in relation to allergen challenge.     

Anti-allergic activity of a Kampo (Japanese herbal) medicine "Sho-seiryu-to (Xiao-Qing-Long-Tang)" on airway inflammation in a mouse model

Effects of a Kampo (Japanese herbal) medicine "Sho-seiryu-to (SST, Xiao-Qing-Long-Tang in Chinese)", which has been used for the treatment of allergic bronchial asthma clinically, were examined on ovalbumin (OVA)-sensitized allergic airway inflammation model (i.e., bronchial asthma) in a mouse. When SST was orally administered at 0.5 g/kg/day from day 1 to 6 days after OVA inhalation, SST reduced the OVA-specific IgE antibody titer in bronchoalveolar lavage (BAL) fluids at 7 days after the OVA inhalation. CD4(+) T cells obtained from the mouse lung produced more interleukin (IL)-4 and IL-5 but less interferon (IFN)-gamma than T cells from nonsensitized control animals. However, oral administration of SST reduced the production of IL-4 and IL-5 and the production of IFN-gamma returned to the control level. In addition, the IL-4 level was increased in the BAL fluid of the OVA-sensitized animals compared to the nonsensitized control, while the IFN-gamma levels decreased. SST reduced the IL-4 levels in the BAL fluids and returned the IFN-gamma level to control levels. Nerve growth factor (NGF) was increased in the BAL fluids of the OVA-sensitized mice over that of nonsensitized mice, but oral administration of SST augmented the NGF levels to approximately 2 times higher than in the sensitized mice. Although lung cells obtained from sensitized mice produced higher levels of NGF than nonsensitized mice, oral administration of SST augmented the production of NGF by the lung cells even higher ( approximately 2 times more than cells from sensitized mice). Administration of anti-NGF antibody to the airway blocked the effects of SST. These results suggest that SST modulates Th1/Th2 balance in the lungs and augmentation of NGF in the lungs may be related to the effects of SST. Pinellic acid (9S, 12S, 13S-trihydroxy-10E-octadecenoic acid), one component of the herbs of SST [Int. Immunopharmacol. 2 (2002) 1183], was purified from the tuber of Pinellia ternata Breitenbach. Oral administration of pinellic acid (50 microg/kg/day) also reduced the OVA-specific IgE antibody titer in BAL fluids from the sensitized mouse. This result suggests that pinellic acid is one of active ingredient(s) in SST.     

ortho-Phthalaldehyde enhances allergen-specific IgE production without allergen-specific IgG in ovalbumin-sensitized mice

ortho-Phthalaldehyde (OPA) is commonly used as a safer and more effective chemical disinfectant for use with medical devices in hospitals. However, the cases of patients with occupational bronchial asthma or contact dermatitis are recently reported among workers in the medical professions who were exposed to OPA disinfectant. Mechanism of allergic reaction associated with OPA is poorly understood. The purpose of this study is that OPA may act as an immunological adjuvant in the allergic reaction accompanied by enhanced specific-IgE production in response to allergen challenge in OVA-sensitized mice. OPA induced increase of total cell numbers, and reflected infiltration of neutrophils in BAL fluid after allergen challenge in sensitized mice, dose-dependently. However, total protein concentration in BAL fluid did not change in the all of groups. The OPA induced up-regulation of eotaxin and monocyte chemotactic protein-1 mRNAs in the lung as well as the increase in OVA-specific IgE in sensitized mice compared with non-sensitized controlled mice without increase in the level of OVA-specific IgG. Cytokines IL-4 and IL-5 mRNA were expressed by allergen (OVA) challenge in both lungs collected from OPA-administrated-sensitized and OPA-administrated-nonsensitized mice. From these data, we concluded that low concentration of OPA that enhanced the OVA-induced recruitment of neutrophils to the lung and the production of allergen-specific IgE, suggesting that OPA acts as an immunological adjuvant.     

Pinocembrin attenuates allergic airway inflammation via inhibition of NF-κB pathway in mice

Pinocembrin, one of the primary flavonoids in propolis, possesses many biological activities, including anti-inflammation, anti-oxidation and immunoregulation. This study aimed to evaluate whether pinocembrin could attenuate ovalbumin (OVA)-induced allergic airway inflammation in mice and to explore the possible mechanism. BALB/c mice sensitized and challenged with OVA were administered intraperitoneally with pinocembrin. Airway inflammation and airway hyperresponsiveness were examined. T-helper type (Th) 2 cytokines in bronchoalveolar lavage fluid (BALF) and OVA-specific immunoglobulin E (IgE) in serum were determined. The activation of nuclear factor kappa B (NF-κB) p65 were also measured. Our results showed that pinocembrin resulted in significant inhibition of pathophysiological signs of allergic asthma, including increased pulmonary eosinophilia infiltration, mucus hypersecretion and airway hyperresponsiveness (AHR). Treatment with pinocembrin significantly reduced Th2 cytokines interleukin (IL)-4, IL-5 and IL-13 in BALF, and OVA-specific IgE in serum. Moreover, pinocembrin treatment suppressed phosphorylation of inhibitor-κBα (IκBα) and NF-κB subunit p65 activation in lung tissue of OVA-sensitized mice. These data suggest that pinocembrin may inhibit allergic airway inflammation, and providing potential benefits in the treatment of inflammatory disease.     

Effects of hardwood smoke exposure on allergic airway inflammation in mice

Hardwood smoke (HWS) from wood burning stoves and fireplaces can be a significant contributor to the composition of ambient air pollution. We hypothesize that the inhalation of HWS by ovalbumin (OVA)-sensitized mice with preexisting lung inflammation leads to the exacerbation of allergic airway responses. Two different models were employed to characterize the effects of inhaled wood smoke on allergic airway inflammation. In both models, male BALB/c mice were sensitized by injection with OVA and alum. In one model, mice were challenged by inhalation with OVA 1 day prior to exposure to HWS (30, 100, 300, or 1000 microg particulate matter [PM]/m(3)) for 6 h/day on 3 consecutive days. In the other model, mice were exposed by inhalation to OVA, rested for 11 days, were exposed to HWS for 3 consecutive days, and then were exposed to OVA immediately after the final HWS exposure. Bronchoalveolar lavage (BAL), and blood collection were performed approximately 18 h after the last HWS or OVA exposure. HWS exposure after the final allergen challenge (first model) led to a significant increase in BAL eosinophils only at the 300 microg/m(3) level. In contrast, changes in BAL cells did not reach statistical significance in the second model. There were no HWS-induced changes in BAL interleukin (IL)-2, IL-4, IL-13, and interferon (IFN)gamma levels in either model following OVA challenge. These results suggest that acute HWS exposure can minimally exacerbate some indices of allergic airway inflammation when a final OVA challenge precedes HWS exposure, but does not alter Th1/Th2 cytokine levels.     

Propolis extracts exhibit an immunoregulatory activity in an OVA-sensitized airway inflammatory animal model

Propolis, which has been used widely in folk medicine, has been shown to exhibit various biological activities but its immunoregulatory and anti-inflammatory activities in intact animals have not been well studied. We investigated these activities of propolis using an ovalbumin-induced asthma animal model. Mice were immunized and sensitized by exposure to ovalbumin (OVA) antigen and administered with low- (65 mg/kg body weight) and high-dose (325 mg/kg body weight) propolis water extracts by tube feeding. The serum OVA-specific IgE titer and cytokine profiles in cultured splenocytes and bronchoalveolar lavage fluids (BALF) were analyzed. The number of eosinophils in BALF was counted. Here we demonstrate that propolis extracts can suppress the serum levels of OVA-specific IgE and IgG(1), and airway hyperresponsiveness (AHR) in OVA-sensitized mice. There are no significant differences in the concentration of eotaxin or the number of eosinophils in BALF among the four groups. However, the higher dose of propolis extracts decreases the level of IL-5 in BALF. The splenocytes from mice administered with propolis extracts (low- and high-dose groups) exhibit a strong inhibition of IL-10 secretion and up-regulation of IFN-gamma secretion in splenocytes stimulated with concanavalin A (ConA). In addition, cytokine (IFN-gamma, IL-6, and IL-10) secretion in OVA-stimulated splenocytes from the propolis groups was significantly lower than that in the control group. These results suggest that propolis extracts may be a potential novel therapeutic agent for asthma.     

Enhancement of the pulmonary allergic granulocyte recruitment in rats exposed to DMTI-II, a Kunitz-type inhibitor isolated from Dimorphandra mollis seeds

DMTI-II (23-kDa trypsin inhibitor purified from Dimorphandra mollis seeds) promotes acute inflammation accompanied by an early infiltration of eosinophils, a critical cell type involved in allergic diseases. We have evaluated here the capacity of DMTI-II to enhance the allergic pulmonary inflammation, looking over time to the leukocyte trafficking from bone marrow to peripheral blood, and their recruitment into the allergic airways. Male Wistar rats were sensitized and challenged with ovalbumin (OVA). At 2 to 16h prior to OVA challenge, animals were exposed to DMTI-II (10μg). Bronchoalveolar lavage fluid (BAL), circulating blood and bone marrow were examined at 24h post-OVA challenge. Challenge with OVA significantly increased the influx of total inflammatory cells, neutrophils and eosinophils in BAL and lung tissue. Pre-exposure to DMTI-II potentiated total inflammatory cell and neutrophil recruitment (p<0.05). Neutropoiesis and neutrophilia accompanied pulmonary cell influx. Pre-exposure to DMTI-II also significantly increased eosinophil recruitment to BAL, an effect starting at 4h, remaining markedly elevated at 16h (p<0.05). Eosinopoiesis and eosinophilia (seen within 2 to 4h) were also observed. Exposure to DMTI-II alone increased the IL-4 levels, and further increased the IL-4 levels in OVA-challenged rats. The levels of IgE, LTB(4) and eotaxin in OVA-challenged rats were greater compared with non-sensitized rats, but DMTI-II exposure failed to further enhance such levels. In summary, our study shows that DMTI-II itself presents granulocytopoietic activity, and enhances allergen-induced neutrophil and eosinophil mobilization from bone marrow to lung tissues that is accompanied by enhanced IL-4 production.     

Total and regional deposition of ultrafine particles in a mouse model of allergic inflammation of the lung

Epidemiological studies have shown an association between ambient particle inhalation and adverse respiratory heath effects. Inhalation of ultrafine particles (UFP, diameter <100 nm) has been suggested to contribute to exacerbation of allergic airway inflammation. Here we analyze the potential effects of allergen sensitization and challenge on total and regional deposition of UFP in the lung. Ovalbumin (OVA)-sensitized and nonsensitized mice were exposed for 1 h to ultrafine iridium particles radiolabeled with (192)Ir (UF-Ir) (0.2 mg m(-3)) at 2 different time points either before or after allergen (OVA) challenge. Additional sensitized and nonsensitized mice were exposed to UF-Ir without allergen challenge. Lung total and regional UF-Ir deposition were calculated according to the distribution of radioactivity in the body and in the excreta during 3 days following UF-Ir inhalation. OVA-sensitized mice showed a 21% relative increase of total UF-Ir deposited fraction compared to nonsensitized mice. When UF-Ir inhalation was performed after allergen challenge, no difference in total UF-Ir deposited fraction between sensitized and nonsensitized mice was detectable. Furthermore, no differences in extrathoracic deposition or in regional particle deposition were detected between all experimental groups. This study indicates that allergen sensitization alone can affect UFP deposition in the lungs. Whether higher UFP deposition in sensitized individuals compared to nonsensitized individuals or whether other factors, like alterations in long-term clearance kinetics, contribute substantially to the susceptibility of allergic individuals to particle exposure has yet to be elucidated.     

Zerumbone enhances the Th1 response and ameliorates ovalbumin-induced Th2 responses and airway inflammation in mice

Zerumbone is a sesquiterpene compound isolated from the rhizome of wild ginger, Zingiber zerumbet Smith. The rhizomes of the plant are used as a spice and traditional medicine. Zerumbone was shown to possess anticarcinogenic, anti-inflammatory, and antioxidant properties. However, the antiallergic activity and the underlying mechanism of zerumbone have not been reported. Herein, we investigated the immunomodulatory effects of zerumbone on antigen-presenting dendritic cells (DCs) in vitro and its potential therapeutic effects against ovalbumin (OVA)-induced T helper 2 (Th2)-mediated asthma in mice. In the presence of zerumbone, lipopolysaccharide-activated bone marrow-derived DCs enhanced T cell proliferation and Th1 cell polarization in an allogeneic mixed lymphocyte reaction. In animal experiments, mice were sensitized and challenged with OVA, and were orally treated with different doses of zerumbone after sensitization. Circulating titers of OVA-specific antibodies, airway hyperresponsiveness to methacholine, histological changes in lung tissues, the cell composition and cytokine levels in bronchoalveolar lavage fluid, and cytokine profiles of spleen cells were assessed. Compared to OVA-induced hallmarks of asthma, oral administration of zerumbone induced lower OVA-specific immunoglobulin E (IgE) and higher IgG_2a antibody production, attenuated airway hyperresponsiveness, prevented eosinophilic pulmonary infiltration, and ameliorated mucus hypersecretion. Zerumbone treatment also reduced the production of eotaxin, keratinocyte-derived chemokine (KC), interleukin (IL)-4, IL-5, IL-10, and IL-13, and promoted Th1 cytokine interferon (IFN)-γ production in asthmatic mice. Taken together, these results suggest that zerumbone exhibits an antiallergic effect via modulation of Th1/Th2 cytokines in an asthmatic mouse model.     

白介素-4和其他因子在天花粉蛋白诱导的卵清白蛋白特异性IgE应答过程中的作用

目的：研究小鼠模型中天花粉蛋白（TCS）诱导的卵清白蛋白（OVA）特异性的E型免疫球蛋白（IgE)应答反应的可能机理。方法：首先用抗白介素-4（IL-4）的单抗治疗TCS和卵清白蛋白（OVA）免疫的小鼠,通过减少内源性IL-4的水平,以观察其对血清中IgE抗体水平的影响。其次,用重组IL-4处理小鼠,通过增加外源性IL-4的水平观察其对血清中OVA特异性IgE形成的影响。最后,我们在TCS免疫小鼠IgE形成过程中,用半定量PCR方法检测了腹腔淋巴结中CD40的配体（CD40L）,肿瘤坏死因子-α（TNF-α）和白介素-13（IL-13）基因表达的趋势。结果：抗IL-4的单抗可以抑制TCS对OVA诱导的特异性IgE的形成,但重组IL-4本身并不能引起OVA特异的IgE应答反应,在TCS的初次和二次免疫中均有较高的表达峰,且CD40L的表达峰与IL-4类似,仅持续较短的时间。结论：IL-4对于TCS诱导的IgE应答反应为必要非充分条件,CD40L、TNF-α和IL-13可能也参与了此过程,其中CD40L可能具有与IL-4同样重要的作用。     

A BALB/c mouse model for assessing the potential allergenicity of proteins: Comparison of allergen dose,sensitization frequency,timepoint and sex

The present study was to investigate the possibility of using the BALB/c mouse as an animal model for assessing the potential allergenicity of proteins.Specific IgE and IgG1 against ovalbumin were induced by dosing BALB/c mice via intraperitoneal injection (absence of adjuvant). The effects of various allergen doses (5 mg, 0.5 mg or 0.05 mg OVA), sensitization times (twice or five times), timepoints (day 14 or day 28) and sex (male or female) were studied. IL-4, IFN-γ, OVA-specific IgE and IgG1 were measured by enzyme-linked immunosorbent assay (ELISA).A general finding was that mice treated with 0.05 mg OVA had the highest OVA-specific IgE and IgG1, statistically significant higher specific IgE and IgG1 were observed in groups sensitized five times than twice, OVA-specific IgE and IgG1 on day 28 were statistically higher than day 14, and higher IL-4 was observed in OVA-allergic mice than control mice.These results demonstrate that the BALB/c mouse model treated with 0.05 mg OVA intraperitoneally on days 0, 3, 6, 9, 12 might be used for further experiments. OVA-specific IgE and IgG1 should be detected on day 28. Further studies including reproducibility and other conditions were required before using the BALB/c mouse model for assessing the potential allergenicity of proteins.     

Enhanced desensitization efficacy by liposomal conjugation of a specific antigen

Since liposomes are known as strong adjuvants, we attempted to use liposomes in immunotherapy as adjuvants, and to achieve desensitization in pre-sensitized mice. At first, we sensitized mice with intraperitoneal injection of model antigen, 100 microg ovalbumin (OVA), with Alum and treated them with liposome composed of distearoylphosphatidylcholine (DSPC) and cholesterol (2:1 as a molar ratio), which was coupled with a small amount of OVA (10 microg OVA in 400 nmol DSPC and 200 nmol cholesterol-liposome was injected into 20 g mouse). It is well known that antigen-specific immunotherapy increases IgG blocking antibodies and decreases in IgE antibodies. The treatment with i.v. injection of OVA-liposome at days 8, 10, and 12 after sensitization strongly suppressed OVA-specific IgE production without affecting IgG level after the boost (100 microg OVA with Alum). Moreover, the treatment with high-density OVA-liposome (10 microg OVA in 80 nmol DSPC and 40 nmol cholesterol-liposome/20 g mouse) not only strongly suppressed IgE levels but also reduced IgG production after the boost of OVA-sensitized mice suggesting the importance of liposomal characteristic in desensitization immunotherapy. Next we reduced the dose of OVA-liposome and the desensitization effect was also observed at the dose of as low as 1 microg OVA on OVA-liposome/mouse. On the contrary, free OVA did not affect the production of both IgG and IgE levels. Biodistribution study indicated that OVA-liposome was highly accumulated in spleen of OVA-sensitized mice compared to control liposome at 3 h after i.v. injection. These results suggest that the liposomal OVA effectively interacts with and desensitizes immune cells, therefore, liposomes coupling with a certain antigen may be effective in allergy immunotherapy.     

Inhalation of concentrated ambient particulate matter near a heavily trafficked road stimulates antigen-induced airway responses in mice

Motor vehicle exhaust emissions are known to exacerbate asthma and other respiratory diseases. Several studies have demonstrated significant associations between living near highly trafficked roadways and increased incidence of asthma and increased severity of asthma-related symptoms, medication usage, and physician visits. This study tested the hypotheses that (1) exposure to particulate matter (PM) near a heavily trafficked Los Angeles freeway would enhance inflammatory and allergic responses in ovalbumin (OVA)-sensitized BALB/c mice compared to sensitized, clean air controls, and (2) there would be differences in response at two distances downwind of heavily traveled freeways because of greater toxicity of PM closest to the freeway. An ambient particle concentrator was used to expose ovalbumin (OVA)-treated BALB/c mice to purified air, to concentrated fine ambient particles, and to concentrated ultrafine airborne particles (CAPs) at 2 distances, 50 m and 150 m, downwind of a roadway that is impacted by emissions from both heavy-duty diesel and light duty gasoline vehicles. Tissues and biological fluids from the mice were analyzed after exposures for 5 days/wk in 2 consecutive weeks. The biomarkers of allergic or inflammatory responses that were assessed included cytokines released by Type 2 T-helper cells (interleukin [IL]-5 and IL-13), OVA-specific immunoglobulin E (IgE), OVA-specific immunoglobulin G1 (IgG1), and pulmonary infiltration of polymorphonuclear leukocytes and eosinophils. IL-5 and IgG1 were significantly increased in mice exposed to CAPs 50 m downwind of the road, compared to responses in mice exposed to purified air, providing evidence of allergic response. No significant increases in allergy-related responses were observed in mice exposed to CAPs 150 m downwind of the road. The biological responses at the 50-m site were significantly associated with organic and elemental carbon components of fine and ultrafine particles (p < or = .05). The primary source of these contaminants at the roadway sites was motor vehicle emissions, suggesting that particulate matter from motor vehicle fuel combustion could exert adjuvant effects and promote the development of allergic airway diseases.     

Warifteine, a bisbenzylisoquinoline alkaloid, decreases immediate allergic and thermal hyperalgesic reactions in sensitized animals

Warifteine is a bisbenzylisoquinoline alkaloid isolated from the Cissampelos sympodialis Eichl (Menispermaceae). This plant is used in the folk medicine for the treatment of airway respiratory diseases. A murine model of immediate allergic reaction was used to evaluate warifteine treatment in the IgE production, leukocyte activation, thermal hyperalgesia, mast cell degranulation and scratching behavior. BALB/c mice treated with warifteine (0.4-10 mg/Kg) 1 h before OVA sensitization reduced OVA induced paw edema as well as the OVA-specific IgE serum titers as compared with non-treated and OVA-sensitized animals. Warifteine also reduced the mice death evoked by IgE-dependent anaphylactic shock reaction at 30 min after intravenous OVA challenge. To assess the effect of warifteine treatment on T cell proliferative response, spleen cells from warifteine treated or non-treated and OVA-sensitized animals were evaluated. Spleen cells from warifteine treated animals (2.0 mg/kg) did not proliferate following OVA stimulation as compared with spleen cell cultures from non-treated animals. This response may be related with the increase of NO production as observed in peritoneal macrophage cultures treated with warifteine. Thermal hyperalgesia evoked by IgE or histamine/5-hydroxytryptamine challenge was inhibited on rats at dose of 4.0 mg/kg. Warifteine treatment (0.6 or 6.0 microg/ml) also decreased the IgEalphaDNP-BSA sensitized mast degranulation after DNP-BSA challenge measured by histamine release. In addition, compound 48/80-induced scratching behavior was also sensitive to warifteine treatment. These results demonstrate for the first time that warifteine treatment reduced the allergy-associated responses.     

Diosgenin, a steroidal sapogenin, enhances antigen-specific IgG2a and interferon-gamma expression in ovalbumin-sensitized BALB/c mice

The effect of diosgenin, the most abundant sapogenin in Chinese yam, on humoral immunity was investigated. Ovalbumin (OVA)-sensitized and challenged BALB/c mice were administered daily with diosgenin for 34 days. The production of OVA-specific serum IgG2a was significantly enhanced by diosgenin treatment, whereas total IgE and OVA-specific IgG1, IgG2a and IgM were unaffected. In parallel with the enhancement of IgG2a, OVA-induced IFN-gamma secretion and mRNA expression were markedly elevated in splenocytes of diosgenin-treated mice, whereas IL-4 expression was unaltered. Furthermore, the expression of T-bet, but not of GATA-3, in splenocytes was up-regulated by diosgenin administration. However, diosgenin treatment did not modulate IL-4 mRNA expression and inflammatory cell infiltration in the lung of OVA-sensitized and challenged mice. Collectively, these data suggest that diosgenin regulates the systemic immune response towards the Th1 direction in response to OVA sensitization. The present study provides evidence to show that intake of diosgenin modulates certain aspects of acquired immunity, including the enhancement of antigen-specific IgG2a and IFN-gamma expression, which may be mediated through the up-regulation of Th1 differentiation.     

Modulation of ovalbumin-induced Th2 responses by second-generation immunomodulatory oligonucleotides in mice

Oligodeoxynucleotides containing unmethylated CpG dinucleotides (CpG DNAs) prevent development of T-helper type 2 (Th2) immune responses and reverse established allergic responses in mouse models. We recently reported that second-generation immunomodulatory oligonucleotides (IMOs) containing novel structures (immunomers) and a synthetic immunostimulatory CpR (R=2'-deoxy-7-deazguanosine) motif induce the production of distinct cytokine secretion profiles in vitro and in vivo. In the present study, we evaluated IMOs containing CpG and CpR motifs to modulate allergen-induced Th2 immune responses in prevention and treatment models. Mice sensitized and challenged with ovalbumin (OVA) were treated with a CpG DNA or an IMO by administration either at the time of OVA sensitization (co-administration; prevention) or after establishment of an allergic response (treatment). Spleens, blood, and lungs were collected and analyzed for immune responses. Spleen-cell cultures harvested from OVA-sensitized mice showed a significant decrease in Th2 cytokine levels with a concomitant increase in Th1 cytokine levels only when CpG DNA or IMOs were co-administered with OVA. The co-administration of CpG DNA or IMOs during OVA sensitization significantly reduced serum OVA-specific and total IgE levels in mice. The mice who received CpG DNA or IMOs co-administered with OVA showed a small reduction in serum OVA-specific and total IgG1 levels and a significant increase in serum OVA-specific and total IgG2a levels. Similar results were found in mice with established allergic responses who received IMO treatment. IMO treatment also resulted in strong inhibition of inflammatory cell infiltration and goblet cell hyperplasia in the lungs compared with untreated mice lungs. These data demonstrate that IMOs prevent antigen-induced Th2 immune responses when co-administered to mice during OVA sensitization and that IMOs reverse established allergic responses induced by OVA.     

The feeding of beta-carotene down-regulates serum IgE levels and inhibits the type I allergic response in mice

Feed containing beta-carotene was administered orally to BALB/c mice immunized intraperitoneally with ovalbumin (OVA) for approximately 1 month. The titers of OVA-specific IgE, OVA-specific IgG1 and OVA-specific IgG2a in the mouse sera were determined. The OVA-specific IgE titer and OVA-specific IgG1 titer by mice fed beta-carotene were significantly inhibited. On the other hand, the OVA-specific IgG2a titer in mice fed beta-carotene was significantly greater than those of control mice. The OVA-specific IgE suppression of beta-carotene feeding was dose-dependent. We also examined the effect of fed beta-carotene on active systemic anaphylaxis. Feeding beta-carotene to mice immunized with OVA inhibited the immediate reduction of the body temperature induced by antigen stimulation. Furthermore, the increase in serum histamine in the mice fed beta-carotene under active systemic anaphylaxis was lower than in controls. We then examined the pattern of cytokine production by spleen cells from mice followed by restimulation with OVA in vitro. The spleen cells from the mice fed beta-carotene produced more IFN-gamma, IL-12 and IL-2 than those from the control group. In contrast, the spleen cells from the mice fed beta-carotene produced less IL-4, IL-5, IL-6, IL-10 than those from the control group. Furthermore, analysis of IFN-gamma mRNA levels of the splenocytes using the real-time quantitative RT-PCR technique revealed higher levels in the splenocytes from the mice fed beta-carotene. These findings suggest that feeding beta-carotene improves the helper T cell (T(H))1-T(H)2 balance, inhibiting specific IgE and IgG1 production and antigen-induced anaphylactic response.     

Dichotomous effect of a traditional Japanese medicine, bu-zhong-yi-qi-tang on allergic asthma in mice

To determine the potentiality of prophylactic and/or therapeutic approaches using a traditional herbal medicine, Bu-zhong-yi-qi-tang (Japanese name: Hochu-ekki-to, HOT), for the control of allergic disease, we examined the effects of oral administration of HOT on a murine model of asthma allergic responses. When oral administration of HOT was begun at the induction phase immediately after OVA sensitization, eosinophilia and Th2-type cytokine production in the airway were reduced in OVA-sensitized mice following OVA inhalation. The serum levels of OVA-specific immunoglobulin (Ig)E and IgG1 were significantly decreased, whereas the level of OVA-specific IgG2a was increased. Interleukin (IL)-4 production by spleen T cells in response to OVA was significantly suppressed, while Interferon (IFN)-gamma production was increased in mice treated with HOT in the induction phase. On the other hand, HOT given in the eliciting phase induced a predominant Th2 response with increased IgE production in OVA-sensitized mice following OVA inhalation. These results suggest that the oral administration of HOT dichotomously modulates allergic inflammation in a murine model for asthma, thus offering a different approach for the treatment of allergic disorders.     

Airway inflammation and adjuvant effect after repeated airborne exposures to di-(2-ethylhexyl)phthalate and ovalbumin in BALB/c mice

BACKGROUND: Epidemiological studies have suggested an association between exposure to phthalate plasticizers, including di-(2-ethylhexyl)phthalate (DEHP), and increased prevalence of asthma, rhinitis or wheezing. Furthermore, studies in mice have demonstrated an adjuvant effect from DEHP after parenteral administration with the model allergen ovalbumin (OVA). OBJECTIVE: Exposures to DEHP were investigated for adjuvant effects and airway inflammation in a mouse inhalation model. METHODS: BALB/cJ mice were exposed to aerosols of 0.022-13 mg/m(3) DEHP and 0.14 mg/m(3) OVA 5 days/week for 2 weeks and thereafter weekly for 12 weeks. Mice exposed to OVA alone or OVA+Al(OH)(3) served as control groups. Finally, all groups were exposed to a nebulized 1% OVA solution on three consecutive days. Serum, bronchoalveolar lavage (BAL) fluid, and draining lymph nodes were collected 24h later. RESULTS: In the OVA+Al(OH)(3) group, significantly increased levels of OVA-specific IgE and IgG1 in serum as well as of eosinophils in BAL fluid were observed. DEHP affected OVA-specific IgG1 production in a concentration-dependent manner, whereas little effect was seen on IgE and IgG2a. Dose-dependent increases in inflammatory cells were observed in BAL fluids, leading to significantly higher lymphocyte, neutrophil and eosinophil numbers in the OVA+13 mg/m(3) DEHP group. Ex vivo cytokine secretion by cultures of draining lymph nodes suggested that DEHP has a mixed Th1/Th2 cytokine profile. CONCLUSION: Airborne DEHP is able to increase serum IgG1 and lung inflammatory cell levels, but only at very high concentrations. Realistic DEHP levels do not have an adjuvant effect or induce allergic lung inflammation in the present mouse model.