RHINOVIRUS INFECTION OF THE AIRWAY EPITHELIUM ENHANCES MAST CELL IMMUNE RESPONSES VIA EPITHELIAL-DERIVED INTERFERONS

Rationale: Mast cells (MCs) within the airway epithelium in asthma are closely related to airway dysfunction, but crosstalk between airway epithelial cells (AECs) and MCs in asthma remains incompletely understood. Human rhinovirus (HRV) infections are key triggers for asthma progression and AECs from individuals with asthma may have dysregulated anti-viral responses. Objectives: We utilize primary phenotyped AECs in an ex vivo coculture model system to examine crosstalk between AECs and MCs following epithelial HRV infection. Methods: Primary AECs were obtained from children with asthma (n=11) and healthy children (n=10), differentiated at air-liquid interface, and cultured in the presence of laboratory of allergic diseases-2 (LAD2) MCs. AECs were infected with HRV serogroup A 16 (HRV16) for 48 hours. RNA isolated from both AECs and MCs underwent RNA-sequencing (RNAseq) analysis. Direct effects of epithelial-derived interferons on LAD2 MCs were examined by qPCR. Results: MCs increased expression of pro-inflammatory and anti-viral genes in AECs. AECs demonstrated a robust antiviral response following HRV16 infection that resulted in significant changes in MC gene expression, including upregulation of genes involved in anti-viral responses, leukocyte activation, and type-2 (T2) inflammation. Subsequent ex vivo modeling demonstrated that IFN-ß induces MC IL13 expression. The effects of AEC phenotype were small relative to the effects of viral infection and the presence of MCs. Conclusions: There is significant crosstalk between AECs and MCs, which are present in the epithelium in asthma. Epithelial-derived interferons not only play a role in viral suppression, but further alter MC immune responses including specific T2 genes. Overall design: Primary AECs obtained from children with asthma (n=11) and healthy children (n=10) and differentiated at air-liquid interface were cultured in the presence and absence of laboratory of allergic diseases-2 (LAD2) MCs. AECs were infected with HRV serogroup A 16 (HRV16) or vehicle control for 48 hours. RNA isolated from both AECs and MCs underwent bulk RNA-sequencing (RNAseq) analysis.