Title | CXC chemokines and antimicrobial peptides in rhinovirus-induced experimental asthma exacerbations. | ||
Author | Rohde, G; Message, S D; Haas, J J; Kebadze, T; Parker, H; Laza-Stanca, V; Khaitov, M R; Kon, O M; Stanciu, L A; Mallia, P; Edwards, M R; Johnston, S L | ||
Journal | Clin Exp Allergy | Publication Year/Month | 2014-Jul |
PMID | 24673807 | PMCID | PMC4403958 |
Affiliation | 1.Department of Respiratory Medicine, National Heart and Lung Institute, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma & Centre for Respiratory Infection, Imperial College London, London, UK; Department of Respiratory Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands. |
RATIONALE: Rhinoviruses (RVs) are the major triggers of asthma exacerbations. We have shown previously that lower respiratory tract symptoms, airflow obstruction, and neutrophilic airway inflammation were increased in experimental RV-induced asthma exacerbations. OBJECTIVES: We hypothesized that neutrophil-related CXC chemokines and antimicrobial peptides are increased and related to clinical, virologic, and pathologic outcomes in RV-induced exacerbations of asthma. METHODS: Protein levels of antimicrobial peptides (SLPI, HNP 1-3, elafin, and LL-37) and neutrophil chemokines (CXCL1/GRO-alpha, CXCL2/GRO-beta, CXCL5/ENA-78, CXCL6/GCP-2, CXCL7/NAP-2, and CXCL8/IL-8) were determined in bronchoalveolar lavage (BAL) fluid of 10 asthmatics and 15 normal controls taken before, at day four during and 6 weeks post-experimental infection. RESULTS: BAL HNP 1-3 and Elafin were higher, CXCL7/NAP-2 was lower in asthmatics compared with controls at day 4 (P = 0.035, P = 0.048, and P = 0.025, respectively). BAL HNP 1-3 and CXCL8/IL-8 were increased during infection (P = 0.003 and P = 0.011, respectively). There was a trend to increased BAL neutrophils at day 4 compared with baseline (P = 0.076). BAL HNP 1-3 was positively correlated with BAL neutrophil numbers at day 4. There were no correlations between clinical parameters and HNP1-3 or IL-8 levels. CONCLUSIONS: We propose that RV infection in asthma leads to increased release of CXCL8/IL-8, attracting neutrophils into the airways where they release HNP 1-3, which further enhances airway neutrophilia. Strategies to inhibit CXCL8/IL-8 may be useful in treatment of virus-induced asthma exacerbations.