An apical-out airway organoid model to study viral infections and assess antiviral drug effects

Airway organoids are complex 3D epithelial structures that recapitulate the organization and many of the key functions of the airway epithelium in vivo. These properties render them an attractive model that can address some of the limitations of traditional 2D and Air-Liquid Interface (ALI) cell culture models. However, the closed architecture of the organoids with the apical side facing the lumen limits their application in assays requiring apical-specific interactions, such as host-pathogen interactions. To circumvent this problem, we have developed the PneumaCult™ Apical-Out Airway Organoid Medium, which is an exctracellular matrix (ECM)-free workflow that promotes generation of a large number of airway organoids that expose their apical surface to the environment. Organoids generated using this method are composed of basal and ciliated cells and demonstrate reproducible morphology, organization and functional characteristics of the airway epithelium. Apical-Out Airway Organoids (AOAO) were susceptible to infection with common airway viruses such as Influenza A, Influenza B, Rhinovirus A16, and Enterovirus D68. The production of high viral RNA titers and distinct cytopathogenic effects (CPE) were detected in all infected AOAO. Application of two antiviral drugs, Rupintrir and Itraconazole, following infection with Enterovirus D68 demonstrated that AOAO are also able to model the inhibitory drug effects. In summary, PneumaCult™ Apical-Out Airway Organoid Medium supports the efficient and reproducible generation of apical out airway organoids that are susceptible to viral infections and show high potential for supporting high-throughput downstream applications.