Mast cells are permissive for rhinovirus replication: potential implications for asthma exacerbations

Area of Science:

• Immunology
• Virology
• Respiratory Medicine

Background:

• Human rhinoviruses (HRVs) are a primary cause of asthma exacerbations.
• The bronchial epithelium is the main site of HRV infection.
• Mast cells (MCs) are increasingly implicated in asthma pathogenesis.

Purpose of the Study:

• To investigate if HRV infection of MCs elicits protective innate immune responses.
• To explore the role of MCs in HRV-induced asthma exacerbations.

Main Methods:

• Infection of MC lines (LAD2) and primary human cord blood-derived MCs (CBMCs) with HRV.
• Assessment of innate immune responses (IFN-β, IFN-λ, ISGs) via RT-qPCR and ELISA.
• Quantification of viral replication and infectious virion release.

Main Results:

• HRV infection induced IFN-β, IFN-λ, and ISG expression in MCs.
• MCs were permissive to HRV replication and release.
• Exogenous IFN-β, but not IFN-λ, protected MCs against HRV infection, while endogenous IFN signaling offered limited protection.

Conclusions:

• MCs support HRV replication and release.
• Exogenous IFN-β treatment can prevent HRV replication in MCs.
• MCs may represent a novel mechanism contributing to HRV-induced asthma exacerbations.