IL-1 receptor anatagonist anakinra reduces neutrophilic airway inflammation in mice with cystic fibrosis-like lung disease

Hypoxic degeneration and necrosis of epithelial cells associated with airway mucus obstruction precedes neutrophilic airway inflammation in βENaC-overexpressing (βENaC-Tg) mice with cystic fibrosis (CF)-like lung disease (Mall MA et al., Am J Respir Crit Care Med., 2008). In many organs sterile neutrophilic inflammation is triggered by necrosis via release of Interleukin-1 alpha (IL-1α) and IL-1 receptor (IL-1R) signaling (Chen CJ et al., Nat Med., 2007). Recently we demonstrated that lack of IL-1R improved survival and reduced neutrophilic airway inflammation, structural lung damage and mucus obstruction in βENaC-Tg mice (Zhou-Suckow Z et al., Pediatr Pulmonol., Suppl 2013). In the present day, we hypothesized that treatment with the IL-1R antagonist anakinra may reduce neutrophilic airway inflammation and ameliorate CF-like lung disease in βENaC-Tg mice. To test this hypothesis, we treated 4 to 6 week old βENaC-Tg mice in established lung disease and wild-type littermates with anakinra (200 mg/kg body weight) or vehicle (NaCl 0.9%) alone by subcutaneous injection twice per day for one week. At the endpoint, we performed bronchoalveolar lavage (BAL) to determine differential cell counts and KC levels, and analyzed histology and morphometry for airway epithelial necrosis, airway mucus obstruction and emphysema. As expected from previous studies of βENaC-Tg mice with genetic deletion of IL-1R, treatment with anakinra had no effect on hypoxic epithelial degeneration. However, anakinra treatment significantly reduced neutrophilic inflammation and KC levels in BAL. Furthermore, mean linear intercepts and destructive index were also reduced by anakinra indicating less structural lung damage in βENaC-Tg mice. These results demonstrate that inhibition of IL-1R signalling provides an effective therapy of CF-like lung disease in mice and suggest anakinra as a potential anti-inflammatory therapy to limit neutrophilic inflammation and associated lung damage in patients with CF and potentially other muco-obstructive lung diseases.

Acknowledgements: Supported by DFG (DFG MA 2081/3 – 3)

*Presenting author