Allergic airway diseases are related to exposure to atmospheric pollutants, which have been suggested to be one factor in the increasing prevalence of asthma. Little is known about the effect of ozone and diesel exhaust particulates (DEP) on the development or aggravation of asthma. We have used a mouse asthma model to determine the effect of ozone and DEP on airway hyperresponsiveness and inflammation. Methacholine enhanced pause (P(enh)) was measured. Levels of IL-4 and IFN-gamma were quantified in bronchoalveolar lavage fluids by enzyme immunoassays. The OVA-sensitized-challenged and ozone and DEP exposure group had higher P(enh) than the OVA-sensitized-challenged group and the OVA-sensitized-challenged and DEP exposure group, and the OVA-sensitized-challenged and ozone exposure group. Levels of IFN-gamma were decreased in the OVA-sensitized-challenged and DEP exposure group and the OVA-sensitized-challenged and ozone and DEP exposure group compared to the OVA-sensitized-challenged and ozone exposure group. Levels of IL-4 were increased in the OVA-sensitized-challenged and ozone exposure group and the OVA-sensitized-challenged and DEP exposure group, and the OVA-sensitized-challenged and ozone and DEP exposure group compared to OVA-sensitized-challenged group. Co-exposure of ozone and DEP has additive effect on airway hyperresponsiveness by modulation of IL-4 and IFN-gamma suggesting that DEP amplify Th2 immune response.
Air Pollutants, Environmental/toxicity ; Animals ; Asthma/*chemically induced/*immunology ; Disease Models, Animal ; Drug Combinations ; Drug Synergism ; Female ; Hypersensitivity/complications/*etiology/*immunology ; Interferon Type II/immunology ; Interleukin-4/immunology ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; Ozone/*toxicity ; Pneumonia/*chemically induced/complications/*immunology ; Research Support, Non-U.S. Gov't ; Respiratory Hypersensitivity/chemically induced/complications/immunology ; Vehicle Emissions/*toxicity

OBJECTIVEAllergic asthma is thought to be mediated by CD4+ T lymphocytes producing the Th2-associated cytokines, which play a critical role in the development of the airway hyper-responsiveness and the eosinophilic inflammatory response. The costimulatory pathway CD28/B7 has been shown to play an important role in CD4+ T cell activation in allergic asthma. This study was conducted to evaluate the role of another costimulatory pathway OX40/OX40 ligand (L) in the pathogenesis of allergic asthma in BALB/c mice.

METHODSAn allergic asthma model in BALB/c mice was established. Thirty-six BALB/c mice were randomly divided into three groups with 12 in each. Mice in treatment group (group B) were treated with neutralizing anti-OX40L monoclonal antibody (mAb, 300 microg per mouse) during the sensitization period. Mice in two control groups, asthma model group (group A) and IgG antibody group (group C) were treated with normal saline (NS) and control IgG respectively instead of anti-OX40L mAb. Bronchoalveolar lavage fluid (BALF) was collected from the mice of each group for counting the total number of white blood cells (including neutrophil granulocyte, lymphocyte, monocyte and eosinophil granulocyte) and the proportions of these cells. The levels of IL-4 and INF-gamma in BALF were measured by ELISA. Lungs were removed for morphological examination after HE and PAS staining, and expression of OX40 in lungs was evaluated by immunohistochemical method.

RESULTS(1) The count of total number of white blood cells in BALF (x10(6)/ml) was lower in group B than that of group A and group C (26.6 +/- 4.6 vs. 36.8 +/- 5.2 and 34.3 +/- 6.9, respectively), the difference between the treatment group (group B) and two control groups (groups A and C) was significant; The proportions of eosinophils and lymphocytes in the BALF (%) were lower in group B than those in group A and group C (eosinophils 15.1 +/- 2.6 vs. 20.0 +/- 4.1 and 19.9 +/- 3.9, respectively; lymphocytes 7.0 +/- 0.9 vs. 8.9 +/- 1.6 and 8.6 +/- 1.8, respectively), the difference between the treatment group and two control groups was significant. (2) The IL-4 level in BALF (pg/ml) was lower in group B than that in group A and group C (672 +/- 58 vs. 809.57 +/- 106.00 and 784 +/- 58, respectively), but the INF-gamma levels in BALF (pg/ml) were higher than those in group A and group C (0.86 +/- 0.09 vs. 0.69 +/- 0.15 and 0.67 +/- 0.13 respectively), and all the differences were statistically significant. (3) The expression of OX40 in the lungs of mice in group B were at a lower level than that of group A and group C, and the morphological changes of asthma were ameliorated in the mice of the treatment group. The signs of mice in treatment group were obviously ameliorated as compared to the two control groups.

CONCLUSIONBlocking the costimulatory pathway by administering the neutralizing anti-OX40L mAb during the sensitization period of allergic asthma model could balance the Th1/Th2 responses, inhibit lung inflammation and ameliorate the signs of mice model of asthma.

Animals ; Antibodies, Monoclonal ; administration & dosage ; immunology ; pharmacology ; Antigens, Differentiation ; immunology ; metabolism ; Asthma ; immunology ; metabolism ; pathology ; therapy ; Bronchoalveolar Lavage Fluid ; cytology ; immunology ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Eosinophils ; immunology ; Female ; Immunoglobulin G ; administration & dosage ; immunology ; pharmacology ; Immunohistochemistry ; Interferon-gamma ; analysis ; immunology ; Interleukin-4 ; analysis ; immunology ; Leukocyte Count ; Leukocytes ; immunology ; Lung ; drug effects ; immunology ; pathology ; Lymphocytes ; immunology ; Membrane Glycoproteins ; immunology ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; toxicity ; Tumor Necrosis Factors ; immunology

OBJECTIVENeonatal Bacillus Calmette-Guerin (BCG) vaccination could decrease asthma prevalence in human according to "hygiene hypothesis". The authors proposed a hypothesis that effect of BCG vaccination on inhibiting asthma in human might be reversed by respiratory virus infection. The objective of this study was to observe combined effects of neonatal BCG vaccination and respiratory syncytial virus (RSV) infection on experimental asthma in mice.

METHODSNeonatal BALB/c mice were divided into five groups. Control and ovalbumin (OVA) groups were mock-vaccinated at birth and mock-infected at 3 weeks of age. BCG + OVA group was BCG-vaccinated and mock-infected. RSV + OVA group was mock-vaccinated and RSV-infected. BCG + RSV + OVA group was BCG-vaccinated and RSV-infected. Except for control group, all the other groups underwent ovalbumin (OVA) sensitization and challenge. Airway responsiveness to inhaled methacholine was measured and bronchoalveolar lavage (BAL) was performed after the last challege. Cells in BAL fluid (BALF) were counted. Cytokines in BALF and serum OVA-specific IgE were detected by ELISA and inflammatory characteristics of lungs was scored by staining with hematoxylin and eosin.

RESULTS(1) The numbers of total white cells, lymphocytes, monocytes, neutrophils, and eosinophils in the BALF from all OVA-sensitized/challenged groups were significantly greater than those in control (P < 0.01), and BCG + OVA group had significantly lower total white cells, lymphocytes and eosinophils as compared with other OVA-sensitized/challenged groups (P < 0.05 or 0.01). (2) All OVA-sensitized/challenged groups had significantly lower IFNgamma (P < 0.05) and higher IL-4 (P < 0.05) level in BALF as compared with control, but there was no significant difference among all OVA sensitized/challenged groups. There was no significant difference in IL-10 level between all experimental groups. (3) All OVA-sensitized/challenged groups showed significantly higher serum OVA-specific IgE titers than control (P < 0.05 or 0.01), but no significant difference was found among all OVA sensitized/challenged groups. (4) RSV + OVA and BCG + RSV + OVA groups displayed the highest airway resistance and subsequently in order as follows: OVA group, BCG + OVA group and control group in severity of airway hyperreactivity (AHR), but no significant difference was found between RSV + OVA and BCG + RSV + OVA groups. (5) Histological score of peribronchiolitis, perivasculitis, alveolitis, and peribronchial eosinophilia in all OVA-sensitized/challenged groups was significantly higher than that in control. BCG + OVA group had significantly milder peribronchiolitis and peribronchial eosinophilia than the other OVA-sensitized/challenged groups (P < 0.05) and significantly milder alveolitis than OVA and BCG + RSV + OVA groups (P < 0.05).

CONCLUSIONNeonatal BCG vaccination decreased asthmatic inflammation and AHR and RSV infection could reverse anti-asthma effect of neonatal BCG vaccination in OVA-sensitized/challenged mouse model.

Animals ; Animals, Newborn ; Asthma ; immunology ; prevention & control ; BCG Vaccine ; administration & dosage ; immunology ; pharmacology ; Bronchoalveolar Lavage Fluid ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Eosinophils ; drug effects ; immunology ; secretion ; Immunoglobulin E ; analysis ; immunology ; Interferon-gamma ; analysis ; immunology ; Interleukin-10 ; analysis ; immunology ; Interleukin-4 ; analysis ; immunology ; Leukocytes ; drug effects ; immunology ; secretion ; Lung ; drug effects ; immunology ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; administration & dosage ; immunology ; toxicity ; Respiratory Syncytial Virus Infections ; immunology ; Respiratory Syncytial Viruses ; immunology ; pathogenicity ; Treatment Outcome

OBJECTIVETo investigate the relationship between atopic allergy and depression and the role of DBP in the development of depression.

METHODSBALB/c mice were randomly divided into eight groups: saline; ovalbumin (OVA)-immunized; saline+DBP (0.45 mg/kg•d); saline+DBP (45 mg/kg•d); DBP (0.45 mg/kg•d) OVA-immunized; DBP (45 mg/kg•d) OVA-immunized; saline+hydrocortisone (30 mg/kg•d); and hydrocortisone (30 mg/kg•d)-exposed OVA-immunized. Behavior (e.g. open-field, tail suspension, and forced swimming tests), viscera coefficients (brain and spleen), oxidative damage [e.g. reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH)], as well as levels of IgE and IL-4, were then analyzed.

RESULTSIn the saline and OVA groups, the degree of depression symptoms in mice increased with increasing DBP concentration. Additionally, the OVA-immunity groups were associated with more serious depressive behavior compared with the same exposure concentration in the saline group. Oxidative damage was associated with a dose-dependent increase in DBP in the different groups. IL-4 and IgE levels were associated with low-dose DBP stimulation, which changed to high-dose inhibition with increasing DBP exposure, possibly due to spleen injury seen at high DBP concentrations.

CONCLUSIONDevelopment of an atopic allergy has the potential to increase the risk of depression in mice, and it seems that DBP helps OVA to exert its effect in our present model. Moreover, the results of our study implicate a certain connection between brain oxidative stress and depression, which deserves a further exploration.

Animals ; Behavior, Animal ; drug effects ; Body Weight ; Depression ; blood ; chemically induced ; immunology ; Dibutyl Phthalate ; immunology ; toxicity ; Environmental Pollutants ; immunology ; toxicity ; Hydrocortisone ; Hypersensitivity, Immediate ; blood ; complications ; Immunization ; Immunoglobulin E ; blood ; Interleukin-4 ; blood ; Male ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; Oxidative Stress

Gap junction channels formed with connexins directly link to the cytoplasm of adjacent cells and have been implicated in intercellular signaling. Connexin 37 (Cx37) is expressed in the gas-exchange region of the lung. Recently, Cx37 has been reported to be involved in the pathogenesis of inflammatory disease. However, no data are available on the role of Cx37 in allergic airway inflammatory disease. In the present study, we used a murine model of ovalbumin (OVA)-induced allergic airway disease and primary murine epithelial cells to examine the change of Cx37 in allergic airway disease. These mice develop the following typical pathophysiological features of asthma: airway hyperresponsiveness, airway inflammation, and increased IL-4, IL-5, IL-13, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, eotaxin, and RANTES levels in lungs. Cx37 protein and mRNA expression were decreased in OVA-induced allergic airway disease. Immunoreactive Cx37 localized in epithelial layers around the bronchioles in control mice, which dramatically disappeared in allergen-induced asthmatic lungs. Moreover, the levels of Cx37 protein in lung tissues showed significantly negative correlations with airway inflammation, airway responsiveness, and levels of Th2 cytokines in lungs. These findings indicate that change of Cx37 may be associated with the asthma phenotype.
Airway Resistance ; Allergens/toxicity ; Animals ; Asthma/etiology/genetics/immunology/*metabolism ; Base Sequence ; Bronchoalveolar Lavage Fluid/cytology ; Cell Adhesion Molecules/metabolism ; Cells, Cultured ; Chemokines/metabolism ; Connexins/genetics/*metabolism ; Cytokines/metabolism ; DNA Primers/genetics ; Disease Models, Animal ; Epithelial Cells/metabolism ; Female ; Lung/immunology/metabolism/pathology ; Mice ; Mice, Inbred C57BL ; Ovalbumin/immunology/toxicity ; RNA, Messenger/genetics/metabolism ; Trachea/metabolism

BACKGROUNDAsthma is a complex disease involving genetic and environment interactions. Atopy is a strong risk factor for asthma. The airway epithelium not only forms a physical barrier but also provides immune defense against harmful materials. To explore the effects of airway epithelium on asthma, we hypothesized that environmental injuries could act on bronchial epithelial cells and damage the physical barrier, which might facilitate allergens to stimulate immunoreactions and play an important role in the pathogenesis of asthma.

METHODSThirty eight-week-old male Wistar rats were randomly divided into five groups with six rats in each group: control group, asthma group, ovalbumin (OVA) + OVA group, lipopolysaccharide (LPS) group and LPS + OVA group. In the control group, 0.9% saline was injected intraperitoneally on day 1. Fourteen days later, the rats were exposed to aerosolized 0.9% saline. In the asthma group, the rats were sensitized with an injection of 10 mg of OVA, followed by an aerosolized 2% OVA challenge 14 days later. The OVA + OVA group was sensitized by an inhalation 2% OVA, 20 minutes a day, from day 1 to day 7, and then OVA challenged in the same way as the asthma group. In the LPS group, LPS (200 µl, 1 µg/µl) was given by airway on day 1 and day 3, with a simultaneous aerosol inhalation of 2% OVA for 20 minutes a day from day 1 to day 7. Fourteen days later, the rats were challenged with saline as in the control group. While in the LPS + OVA group, LPS (200 µl, 1 µg/µl) was given by airway on day 1 and day 3, with a simultaneous aerosol inhalation of 2% OVA for 20 minutes a day from day 1 to day 7. Fourteen days later, the rats were challenged with OVA as in the asthma group. The expression of interleukin (IL)-4, interferon-gamma (IFN-γ) and thymic stromal lymphopoietin (TSLP) in the lungs was detected by reverse transcription polymerase chain reaction (RT-PCR) and the pulmonary pathological changes were also observed. The level of IL-4, IFN-γ and IgE in plasma was detected by enzyme-linked immunosorbent assay (ELISA). Bronchoalveolar lavage fluid (BALF) was collected to conduct differential cell counts. Flow cytometry analysis was also used to count Th1 and Th2 cells.

RESULTSThe pathological changes in the LPS + OVA group were similar to the asthma group, while in other groups, the pathological changes were not obvious. The ratio of lymphocytes in BALF, IL-4/IFN-γ in plasma and the expression of the TSLP and IL-4 in the asthma and LPS + OVA groups were higher than in the control group and the OVA + OVA group (P < 0.05). The level of IgE was higher in the asthma, LPS and LPS + OVA groups than in the control group and the OVA + OVA group (P < 0.05). By flow cytometry analysis, the Th1/Th2 ratio was lower in the LPS + OVA and asthma groups than in other groups (P < 0.05).

CONCLUSIONSThe experiment results show that the injury to the bronchial epithelial layer may be the initial event of allergic responses. This finding implies that a rational approach to therapeutics would be to increase the resistance of the airways to environmental injuries rather than concentrating on suppressing inflammation.

Animals ; Bronchi ; pathology ; Cell Count ; Cytokines ; physiology ; Disease Models, Animal ; Epithelial Cells ; pathology ; Hypersensitivity ; etiology ; Immunoglobulin E ; blood ; Interferon-gamma ; blood ; Interleukin-4 ; blood ; Lipopolysaccharides ; toxicity ; Male ; Ovalbumin ; immunology ; Rats ; Rats, Wistar