ovalbumin and Pseudomonas-Infections

Glucocorticoids are widely regarded as the most effective treatment for asthma. However, the direct impact of glucocorticoids on the innate immune system and antibacterial host defense during asthma remain unclear. Understanding the mechanisms underlying this process is critical to the clinical application of glucocorticoids for asthma therapy. After sensitization and challenge with ovalbumin (OVA), BALB/c mice were treated with inhaled budesonide and infected with Pseudomonas aeruginosa (P. aeruginosa). The number of viable bacteria in enflamed lungs was evaluated, and levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in serum were measured. A lung epithelial cell line was pretreated with budesonide. Levels of cathelicidin-related antimicrobial peptide (CRAMP) were measured by immunohistochemistry and western blot analysis. Intracellular bacteria were observed in lung epithelial cells.. Inhaled budesonide enhanced lung infection in allergic mice exposed to P. aeruginosa and increased the number of viable bacteria in lung tissue. Higher levels of IL-4 and lower levels of IFN-γ were observed in the serum. Budesonide decreased the expression of CRAMP, increased the number of internalized P. aeruginosa in OVA-challenged mice and in lung epithelial cell lines. These data indicate that inhaled budesonide can suppress pulmonary antibacterial host defense by down-regulating CRAMP in allergic inflammation mice and in cells in vitro.. Inhaled budesonide suppressed pulmonary antibacterial host defense in an asthmatic mouse model and in lung epithelium cells in vitro. This effect was dependent on the down-regulation of CRAMP.

Topics: Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Budesonide; Cathelicidins; Colony Count, Microbial; Down-Regulation; Epithelial Cells; Host-Pathogen Interactions; Hypersensitivity; Immunosuppression Therapy; Inflammation; Interferon-gamma; Interleukin-4; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Pseudomonas aeruginosa; Pseudomonas Infections

ATP has been defined as a key mediator of asthma. In this study, we evaluated lung inflammation in mice deficient for the P2Y(2) purinergic receptor. We observed that eosinophil accumulation, a distinctive feature of lung allergic inflammation, was defective in OVA-treated P2Y(2)-deficient mice compared with OVA-treated wild type animals. Interestingly, the upregulation of VCAM-1 was lower on lung endothelial cells of OVA-treated P2Y(2)(-/-) mice compared with OVA-treated wild type animals. Adhesion assays demonstrated that the action of UTP on leukocyte adhesion through the regulation of endothelial VCAM-1 was abolished in P2Y(2)-deficient lung endothelial cells. Additionally, the level of soluble VCAM-1, reported as an inducer of eosinophil chemotaxis, was strongly reduced in the bronchoalveolar lavage fluid (BALF) of P2Y(2)-deficient mice. In contrast, we observed comparable infiltration of macrophages and neutrophils in the BALF of LPS-aerosolized P2Y(2)(+/+) and P2Y(2)(-/-) mice. This difference could be related to the much lower level of ATP in the BALF of LPS-treated mice compared with OVA-treated mice. Our data define P2Y(2) as a regulator of membrane and soluble forms of VCAM-1 and eosinophil accumulation during lung inflammation.

Topics: Acute Lung Injury; Animals; Cell Line; Cell Membrane; Cell Movement; Disease Models, Animal; Eosinophils; Lipopolysaccharides; Lung; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Protein Isoforms; Pseudomonas Infections; Receptors, Purinergic P2Y2; Solubility; Vascular Cell Adhesion Molecule-1

The design for a simple, low-cost aerosol generation system for rodent inhalation studies is described here. This system is appropriate for low biohazard-level agents. In this study, two biosafety level 2 agents, Pasturella pneumotropica and Pseudomonas aeruginosa, were tested successfully. This system was also used to immunize mice and guinea pigs in ovalbumin-based models of pulmonary inflammation. This design is appropriate for studies with limited budgets and lower-level biosafety containment.

Topics: Administration, Inhalation; Aerosols; Animals; Disease Models, Animal; Equipment Design; Female; Guinea Pigs; Inhalation Exposure; Mice; Nebulizers and Vaporizers; Ovalbumin; Pasteurella Infections; Pasteurella pneumotropica; Pneumonia; Pseudomonas Infections

In the cystic fibrosis (CF) patient, lung function decreases throughout life as a result of continuous cycles of infection, particularly with Pseudomonas aeruginosa and Staphylococcus aureus. The mechanism underlying the pathophysiology of the disease in humans has not been established. However, it has been suggested that abnormal, tenacious mucus, resulting perhaps from improper hydration from loss of Cl- secretion via the cystic fibrosis transmembrane conductance regulator (CFTR) protein, impairs clearance of bacteria from the CF airway and provides an environment favorable to bacterial growth. If this hypothesis is correct, it could explain the absence of respiratory disease in CFTR-deficient mice, since mice have only a single submucosal gland and display few goblet cells in their lower airways, even when exposed to bacteria. To test this hypothesis further, we induced allergic airway disease in CFTR-deficient mice. We found that induction of allergic airway disease in mice, unlike bacterial infection, results in an inflammatory response characterized by goblet cell hyperplasia, increased mucin gene expression, and increased production of mucus. However, we also found that disease progression and resolution is identical in Cftr-/- mice and control animals. Furthermore, we show that the presence of mucus in the Cftr-/- airway does not lead to chronic airway disease, even upon direct inoculation with S. aureus and P. aeruginosa. Therefore, factors in addition to the absence of high levels of mucus secretion protect the mouse from the airway disease seen in human CF patients.

Topics: Animals; Cystic Fibrosis Transmembrane Conductance Regulator; Gene Expression; Goblet Cells; Hyperplasia; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred DBA; Mucins; Ovalbumin; Pseudomonas Infections; Respiratory Hypersensitivity; Respiratory Tract Diseases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Staphylococcal Infections

The pathomechanism of the bronchospastic reaction is not fully explained. Ovalbumin induced bronchospastic reaction in guinea pigs is widely accepted as a classical experimental model and was appleid in this study. The bronchoconstriction, bronchial hypersensitivity and humoral immune response were measured after bronchial infection and chemical injury by formalin vapours. The intensity of the bronchospasm was measured by Lundberg index, the haemolytic activity of complement and the level of circulating immune complexes were measured at the beginning and at the end of the experiment. The increase of the bronchospastic reaction and bronchial hypersensitivity was observed bacterial infection and after formalin vapours too. Bronchial infection and chemical irritation of bronchial tree lead to the increase of the circulating immune complexes level and to the decrease of the haemolytic activity of the complement.

Topics: Animals; Antibody Formation; Antigen-Antibody Complex; Bronchial Spasm; Complement System Proteins; Female; Formaldehyde; Guinea Pigs; Ovalbumin; Pseudomonas Infections; Respiratory Hypersensitivity

The purpose of the research was to observe the influence of the bacterial infection and inhalation vapours on the histologic picture of bronchi and lungs in the course on the experimental asthma induced in guinea pigs. The animals were divided into 6 groups. The animals were immunized by ovalbumin. Group I was control and was subjected to inhalations of physiologic salt solutions. Group II was immunized by the soluble of ovalbumin intraperitoneally and was inhaled with the solution of ovalbumin. Group III was subjected only to inhalation of the ovalbumin. Group IV was inhaled with the solution of formalin alternately. Group V experienced only formalin inhalations. Group VI was infected with Pseudomonas aeruginosa strain and inhaled with the solution of ovalbumin. On the histologic examination of the lung tissue the authors found the atrophy of the lymphatic system, the hypertrophy of the mucous membrane and muscular coat of the bronchi, the accumulation of large amount of mucus in their lumen and the exfoliation of the bronchial epithelium.

Topics: Animals; Asthma; Atrophy; Bronchi; Bronchial Spasm; Epithelium; Formaldehyde; Guinea Pigs; Hypertrophy; Lung; Male; Mucous Membrane; Ovalbumin; Pseudomonas Infections

The pathomechanism of bronchial asthma is not fully explained. The immunologic reactions in the bronchial epithelium may be better understood by an experimental approach in laboratory animals. Ovalbumin induced asthma in guinea pigs is widely accepted as an experimental model of bronchial asthma and was applied in this study. The bronchoconstriction, bronchial hypersensitivity and humoral immune response were measured after bronchial infection (intranasal Pseudomonas aeruginosa application). The increase of the bronchospastic reaction and bronchial hypersensitivity was observed after intranasal Pseudomonas aeruginosa application. Bacterial infection lead to the increase of the circulating immune complexes level and to the decrease of the haemolytic activity of the complement in serum.

Topics: Animals; Antibody Formation; Antigen-Antibody Complex; Asthma; Complement System Proteins; Female; Guinea Pigs; Ovalbumin; Pseudomonas Infections