Résumé
PURPOSE: The aim of the present study was to investigate the differences in lower airway inflammatory immune responses, including cellular responses and responses in terms of inflammatory mediators in bronchoalveolar lavage fluid (BALF) and the airway, to rhinovirus (RV) infection on asthma exacerbation by comparing a control and a murine asthma model, with or without RV infection. METHODS: BALB/c mice were intraperitoneally injected with a crude extract of Dermatophagoides farinae (Df) or phosphate buffered saline (PBS) and were subsequently intranasally treated with a crude extract of Df or PBS. Airway responsiveness and cell infiltration, differential cell counts in BALF, and cytokine and chemokine concentrations in BALF were measured 24 hours after intranasal RV1B infection. RESULTS: RV infection increased the enhanced pause (Penh) in both the Df sensitized and challenged mice (Df mice) and PBS-treated mice (PBS mice) (P<0.05). Airway eosinophil infiltration increased in Df mice after RV infection (P<0.05). The levels of interleukin (IL) 13, tumor necrosis factor alpha, and regulated on activation, normal T cells expressed and secreted (RANTES) increased in response to RV infection in Df mice, but not in PBS mice (P<0.05). The level of IL-10 significantly decreased following RV infection in Df mice (P<0.05). CONCLUSION: Our findings suggest that the augmented induction of proinflammatory cytokines, Th2 cytokines, and chemokines that mediate an eosinophil response and the decreased induction of regulatory cytokines after RV infection may be important manifestations leading to airway inflammation with eosinophil infiltration and changes in airway responsiveness in the asthma model.
Sujets)
Animaux , Souris , Asthme , Liquide de lavage bronchoalvéolaire , Numération cellulaire , Chimiokines , Cytokines , Dermatophagoides farinae , Granulocytes éosinophiles , Inflammation , Interleukine-10 , Interleukines , Rhinovirus , Lymphocytes T , Facteur de nécrose tumorale alphaRésumé
PURPOSE: The environmental factors human rhinoviruses (HRVs) and house dust mites (HDMs) are the most common causes of acute exacerbations of asthma. The aim of this study was to compare the chemokine production induced by HRVs in airway epithelial cells with that induced by other respiratory viruses, and to investigate synergistic interactions between HRVs and HDMs on the induction of inflammatory chemokines in vitro. METHODS: A549 human airway epithelial cells were infected with either rhinovirus serotype 7, respiratory syncytial virus (RSV)-A2 strain, or adenovirus serotype 3 and analyzed for interleukin (IL)-8 and regulated on activation, normal T-cell expressed and secreted (RANTES) release and mRNA expression. Additionally, activation of nuclear factor (NF)-kappaB and activator protein (AP)-1 were evaluated. The release of IL-8 and RANTES was also measured in cells stimulated simultaneously with a virus and the HDM allergen, Der f1. RESULTS: HRV caused greater IL-8 and RANTES release and mRNA expression compared with either RSV or adenovirus. NF-kappaB and AP-1 were activated in these processes. Cells incubated with a virus and Der f1 showed an increased IL-8 release. However, compared with cells incubated with virus alone as the stimulator, only HRV with Der f1 showed a statistically significant increase. CONCLUSIONS: IL-8 and RANTES were induced to a greater extent by HRV compared with other viruses, and only HRV with Der f1 acted synergistically to induce bronchial epithelial IL-8 release. These findings may correspond with the fact that rhinoviruses are identified more frequently than other viruses in cases of acute exacerbation of asthma.
Sujets)
Humains , Adenoviridae , Antigènes de Dermatophagoides , Protéines d'arthropode , Asthme , Chimiokine CCL5 , Chimiokines , Cysteine endopeptidases , Cellules épithéliales , Interleukine-8 , Interleukines , Facteur de transcription NF-kappa B , Pyroglyphidae , Virus respiratoires syncytiaux , Rhinovirus , ARN messager , Entorses et foulures , Lymphocytes T , Facteur de transcription AP-1 , VirusRésumé
PURPOSE: Synthesis of regulated on activation, normal T-cells expressed and secreted (RANTES) in the airway has previously been shown to be elevated after respiratory syncytial virus (RSV) infection. However, since few studies have examined whether RSV-infected asthma patients express a higher level of RANTES than do normal individuals, we used a murine model of asthma to address this question. METHODS: We prepared Dermatophagoides farinae-sensitized mice as an asthma model, and then infected them with RSV and analyzed the changes in airway responsiveness and the cell populations and cytokine levels of bronchoalveolar lavage fluid. RESULTS: RANTES synthesis increased in response to RSV infection in both control mice and in asthma model (D. farinae) mice. However, there was no significant difference in the amount of RANTES produced following RSV infection between control and D. farinae mice. RSV infection affected neither interferon-gammasynthesis nor airway responsiveness in either control or D. farinae mice. CONCLUSION: RSV infection did not induce more RANTES in a murine model of asthma than in control mice.
Sujets)
Animaux , Humains , Souris , Asthme , Lavage bronchoalvéolaire , Chimiokine CCL5 , Modèles animaux , Pyroglyphidae , Virus respiratoires syncytiaux , Lymphocytes TRésumé
PURPOSE: Synthesis of regulated on activation, normal T-cells expressed and secreted (RANTES) in the airway has previously been shown to be elevated after respiratory syncytial virus (RSV) infection. However, since few studies have examined whether RSV-infected asthma patients express a higher level of RANTES than do normal individuals, we used a murine model of asthma to address this question. METHODS: We prepared Dermatophagoides farinae-sensitized mice as an asthma model, and then infected them with RSV and analyzed the changes in airway responsiveness and the cell populations and cytokine levels of bronchoalveolar lavage fluid. RESULTS: RANTES synthesis increased in response to RSV infection in both control mice and in asthma model (D. farinae) mice. However, there was no significant difference in the amount of RANTES produced following RSV infection between control and D. farinae mice. RSV infection affected neither interferon-gammasynthesis nor airway responsiveness in either control or D. farinae mice. CONCLUSION: RSV infection did not induce more RANTES in a murine model of asthma than in control mice.