Anales RANF

P.81 ROLE OF CD73 IN THE DEVELOPMENT OF MURINE ALLERGIC ASTHMA E. Caiazzo 1 , F. Roviezzo 1 , MA. Riemma 1 , I. Cerqua 1 , S. Morello 2 , A. Ialenti 1 , C. Cicala 1 1 University of Naples Federico II, Naples, Italy; 2 University of Salerno, Fisciano, Italy. Background: Allergic asthma is the most frequent respiratory disease. CD73 is the key enzyme in the extracellular adenosine production from adenosine monophosphate (AMP) [1]. To date, very little is known about the role of CD73 enzyme in the development of allergic asthma [2]. Our study was aimed to investigate the role of CD73 in the development of allergic sensitization and in the tissue response to allergen exposure. Material and methods: Experiments were performed on female wild type (wt) and CD73-deficient (CD73 -/- ) mice. Animals were sensitized by subcutaneous injection with 100 µg of ovalbumin (OVA) on day 1 and day 8. 21 days thereafter, mice were twice challenged with 5% aerosolized OVA or with saline as control. All mice were sacrificed 24 h after the last challenge to take main bronchi, pulmonary tissue and blood for functional, molecular and cellular studies. Results: OVA sensitization induced a significant increase in CD73 bronchi expression and plasma activity (n=7, ***p<0.001). In sensitized-allergen challenged mice, plasma IgE levels tended to be higher in CD73 -/- mice compared to wt mice. In addition, in sensitized-allergen challenged mice, we observed elevated peribronchial inflammation, goblet cell metaplasia and mucus production, that were further increased in lung sections of CD73 -/- mice. On the other hand, in vitro bronchial reactivity to carbachol was not increased by exposure to allergen in CD73 -/- mice (n=8, **p<0.01). Conclusions: Our data suggest that CD73 enzyme plays a dual role in the development of allergic asthma. References: [1] Cicala C, Ialenti A. Eur. J. Pharmacol., 2013, 714: 522-525. [2] Bentley JK et al., Respir Res., 2010, 11:127.