Alexis Celle1, Pauline Esteves1, Guillaume Cardouat1, Fabien Beaufils2, Edmée Eyraud1, Isabelle Dupin1, Elise Maurat1, Sabrina Lacomme3, Olga Ousova1, Hugues Begueret4, Matthieu Thumerel2, Roger Marthan2, Pierre-Olivier Girodet2, Patrick Berger2, Thomas Trian5. 1. Univ-Bordeaux, Centre de Recherche Cardio-thoracique de Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, Bordeaux, France; INSERM, Centre de Recherche Cardio-thoracique de Bordeaux, Bordeaux, France. 2. Univ-Bordeaux, Centre de Recherche Cardio-thoracique de Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, Bordeaux, France; INSERM, Centre de Recherche Cardio-thoracique de Bordeaux, Bordeaux, France; CHU de Bordeaux, Service d'exploration fonctionnelle respiratoire, Service de chirurgie, Bordeaux, France. 3. Univ-Bordeaux, Centre de Recherche Cardio-thoracique de Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, Bordeaux, France. 4. CHU de Bordeaux, Service d'exploration fonctionnelle respiratoire, Service de chirurgie, Bordeaux, France. 5. Univ-Bordeaux, Centre de Recherche Cardio-thoracique de Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, Bordeaux, France; INSERM, Centre de Recherche Cardio-thoracique de Bordeaux, Bordeaux, France. Electronic address: thomas.trian@u-bordeaux.fr.
Abstract
BACKGROUND: Patients with severe asthma show an increase in both exacerbation frequency and bronchial smooth muscle (BSM) mass. Rhinovirus (RV) infection of the bronchial epithelium (BE) is the main trigger of asthma exacerbations. Histological analysis of biopsies shows that a close connection between BE and hypertrophic BSM is a criterion for severity of asthma. OBJECTIVE: We hypothesized that RV infection of BE specifically increases BSM-cell migration from patients with asthma. METHODS: Serum samples, biopsies, or BSM cells were obtained from 86 patients with severe asthma and 31 subjects without asthma. BE cells from subjects without asthma were cultured in an air-liquid interface and exposed to RV-16. Migration of BSM cells was assessed in response to BE supernatant using chemotaxis assays. Chemokine concentrations were analyzed by transcriptomics and ELISAs. Immunocytochemistry, western blotting, and flow cytometry were used to quantify CXCR3 isoform distribution. CXCR3 downstream signaling pathways were assessed by calcium imaging and western blots. RESULTS: BSM cells from patients with severe asthma specifically migrated toward RV-infected BE, whereas those from subjects without asthma did not. This specific migration is driven by BE C-X-C motif chemokine ligand 10, which was increased in vitro in response to RV infection as well as in vivo in serum from exacerbating patients with severe asthma. The mechanism is related to both decreased expression and activation of the CXCR3-B-specific isoform in BSM cells from those with severe asthma. CONCLUSIONS: We have demonstrated a novel mechanism of BSM remodeling in patients with severe asthma following RV exacerbation. This study highlights the C-X-C motif chemokine ligand 10/CXCR3-A axis as a potential therapeutic target in severe asthma.
BACKGROUND: Patients with severe asthma show an increase in both exacerbation frequency and bronchial smooth muscle (BSM) mass. Rhinovirus (RV) infection of the bronchial epithelium (BE) is the main trigger of asthma exacerbations. Histological analysis of biopsies shows that a close connection between BE and hypertrophic BSM is a criterion for severity of asthma. OBJECTIVE: We hypothesized that RV infection of BE specifically increases BSM-cell migration from patients with asthma. METHODS: Serum samples, biopsies, or BSM cells were obtained from 86 patients with severe asthma and 31 subjects without asthma. BE cells from subjects without asthma were cultured in an air-liquid interface and exposed to RV-16. Migration of BSM cells was assessed in response to BE supernatant using chemotaxis assays. Chemokine concentrations were analyzed by transcriptomics and ELISAs. Immunocytochemistry, western blotting, and flow cytometry were used to quantify CXCR3 isoform distribution. CXCR3 downstream signaling pathways were assessed by calcium imaging and western blots. RESULTS: BSM cells from patients with severe asthma specifically migrated toward RV-infected BE, whereas those from subjects without asthma did not. This specific migration is driven by BE C-X-C motif chemokine ligand 10, which was increased in vitro in response to RV infection as well as in vivo in serum from exacerbating patients with severe asthma. The mechanism is related to both decreased expression and activation of the CXCR3-B-specific isoform in BSM cells from those with severe asthma. CONCLUSIONS: We have demonstrated a novel mechanism of BSM remodeling in patients with severe asthma following RV exacerbation. This study highlights the C-X-C motif chemokine ligand 10/CXCR3-A axis as a potential therapeutic target in severe asthma.