Adeno-associated viral vector-mediated anti-inflammasome gene transfer alleviates asthmatic airway inflammation in OVA-sensitized mice model

Abstract

Abstract Bronchial asthma is a chronic inflammatory disorder of the airway characterized by airway hyperresponsiveness (AHR), pulmonary eosinophilia, elevated serum IgE, and dysregulated T helper (Th) 2 cytokines. It is becoming urgent to identify target molecules for the preventive and therapeutic purpose. ATP accumulation in bronchoalveolar lavage fluid (BALF) of asthmatic subjects indicates that extracellular ATP and the downstream responses are involved. ATP is an activator of NLRP3 inflammasomes and tightly regulated by CD39, a nucleoside triphosphate diphosphohydrolase encoded by entpd1. Upregulated BALF ATP levels and decreased CD39 RNA were accompanied with asthmatic cardinal features in ovalbumin (OVA)-sensitized mice. Recombinant adeno-associated virus (rAAV) has been developed to carry exogenous genes with safe and low toxic therapeutic potential. The different serotypes and tropisms of AAVs benefit tissue specific gene targeting. This study aims for determining whether lung-targeting rAAV carrying CD39 (AAV/CD39) is able to reduce extracellular ATP in BALF and inhibit the OVA-induced allergic inflammation in an asthmatic murine model. The mice were sensitized and challenged with OVA. rAAV vectors were administrated into the lungs of mice 3 days before the first OVA exposure. The data indicated that ATP levels in BALF were downregulated accompanied with rescued CD39 expression. The administration of AAV/CD39 was able to suppress AHR, pulmonary eosinophilia, and the production of IL-5 from OVA-activated mediastinal lymph nodes (MLNs) cells. The treatment of AAV/CD39 attenuated the asthmatic airway inflammation and AHR. Collectively, ATP could be a potential target for gene therapy on asthma.