TY - JOUR T1 - In vivo effects of corticosteroid plus long-acting beta2-agonist on the expression of B7-H1/PD-L1 in double-stranded RNA-induced lung inflammation JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P863 AU - Saaka Hamano AU - Koichiro Matsumoto AU - Satoru Fukuyama AU - Keiko Kan-o AU - Nanae Seki AU - Ken Tonai AU - Takako Nakano AU - Hiromasa Inoue AU - Yoichi Nakanishi Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P863.abstract N2 - Background and Aim: Airway viral infection exacerbates asthma and COPD. B7-H1/PD-L1 is a coinhibitory molecule implicated in an escape mechanism of viruses from the host immune systems. This escape may induce viral persistence and lead to the exacerbation. In ERS international congress 2013, we showed that an analog of viral double-strand RNA, polyinosinic-polycytidylic acid (poly I:C), upregulated the expression of B7-H1/PD-L1 on airway epithelial cells in vitro, which was resistant to corticosteroid treatment. Although this resistance was overcome by addition of long-acting beta2-agonist (LABA), in vivo evidence remained uncertain. We examined the effect of corticosteroid plus LABA on the expression of B7-H1/PD-L1 in vivo.Methods: We established a murine model of double-stranded RNA-induced inflammation by an intratracheal administration (i.t.) of poly I:C. The expression of B7-H1/PD-L1 in epithelial cells was assessed by flow cytometry as well as assessment of inflammation in bronchoalveolar lavage fluid (BALF). The effects of ciclesonide and/or indacaterol (i.t.) were examined.Results: Poly I:C induced upregulation of B7-H1/PD-L1 in epithelial cells and neutrophilia in BALF. The upregulation was suppressed by low-concentration ciclesonide in combination with indacaterol. This combination also suppressed neutrophilia in BALF.Conclusion: Corticosteroid plus LABA attenuates double-stranded RNA-induced upregulation of B7-H1/PD-L1 in vivo. This mechanism may partly explain a beneficial effect of combination therapy on virus-associated exacerbation of asthma and COPD. ER -