Respiratory syncytial virus increases eosinophil extracellular traps in a murine model of asthma
10.5415/apallergy.2019.9.e32
- Author:
Josiane Silva SILVEIRA
1
;
Géssica Luana ANTUNES
;
Rodrigo Benedetti GASSEN
;
Ricardo Vaz BREDA
;
Renato Tetelbom STEIN
;
Paulo Márcio PITREZ
;
Aline Andrea DA CUNHA
Author Information
1. Department of Biochemistry, Laboratory of Neuroprotection and Neurometabolic Disease, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
- Publication Type:Original Article
- Keywords:
Asthma;
Inflammation;
Eosinophil peroxidase;
Extracellular traps;
Respiratory syncytial viruses
- MeSH:
Animals;
Annexin A5;
Asthma;
Bronchoalveolar Lavage Fluid;
DNA;
Eosinophil Peroxidase;
Eosinophils;
Extracellular Traps;
In Vitro Techniques;
Inflammation;
Injections, Subcutaneous;
Mice;
Microscopy, Confocal;
Ovalbumin;
Propidium;
Respiratory Syncytial Viruses
- From:
Asia Pacific Allergy
2019;9(4):e32-
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Respiratory viral infections are the leading cause of asthma exacerbations. Eosinophil activation results in the formation of eosinophil extracellular traps (EETs), which release web-like structures of DNA and proteins that bind, disarm and extracellularly kill pathogens. OBJECTIVE: We investigated whether the respiratory syncytial virus (RSV) in vitro could induce EETs in bronchoalveolar lavage fluid eosinophils in a murine model of asthma. METHODS: BALB/cJ mice (6–8 weeks old) were sensitized with 2 subcutaneous injections of ovalbumin (20 μg) on days 0 and 7, followed by three intranasal challenges with ovalbumin (100 μg) on days 14, 15, and 16 of the protocol. The control group received Dulbecco's phosphate-buffered saline. Bronchoalveolar lavage fluid eosinophils of ovalbumin group or control group were stimulated with RSV (103 PFU/mL) in vitro for 3 hours. After that, culture supernatant was collected to perform the analyses proposed in this study. RESULTS: We verified an increase in extracellular DNA concentration in bronchoalveolar lavage fluid eosinophils from ovalbumin group stimulated with RSV (10³ PFU/mL) in vitro, which was confirmed by confocal microscopy. We demonstrated that most cells are negative for annexin V and propidium iodide in all groups evaluated. Also, RSV in vitro decreased interferon-ɣ in culture supernatant when compared to the ovalbumin group. CONCLUSION: In this study, we demonstrated for the first time that RSV in vitro induces EETs formation in eosinophils from asthmatic mice.
