Immune mechanisms of respiratory viral infections in asthma

- Viral sensing and intracellular signalling pathways are dysregulated in asthma.
- Improving interferon responses, with anti-IgE treatment, reduces viral exacerbations.
- Epithelial-derived cytokines orchestrate type 2 immunopathology in viral infections in allergic asthma.

The more severe pathology respiratory viral infections produce in asthma sufferers is a result of a dysregulated immune response. Excess type 2 inflammation is a well-described feature of virally induced asthma exacerbations, with growing evidence that production of antiviral interferons may also be impaired. However, the mechanisms underlying these are little understood. This review summarizes the current understanding and recent discoveries of the cellular and molecular events that follow viral infections in asthma. In particular, we discuss differences in viral sensing and intracellular signalling pathways upstream of interferon induction in asthma, and the role of epithelial-derived cytokines in orchestrating type 2 immunopathology, including type 2 innate lymhpoid cells (ILC2s).