Epigenetic Training of the Airways: How Rhinovirus Infections Imprint the Bronchial Epithelium

Repeated infections with rhinoviruses can induce epigenetic changes in the human bronchial epithelium. Researchers from the German Center for Lung Research (DZL) have now demonstrated for the first time that structural airway cells can develop a form of "trained immunity". The results have been published in the journal Allergy.

In their study, the scientists repeatedly infected bronchial epithelial cells (BEAS-2B) with rhinovirus type 16 and subsequently analyzed changes in gene expression and DNA methylation. They identified 77 genes whose activity systematically changed following repeated viral stimulation. These genes are associated with signal transduction, immune response, and cell communication.

Focus on Altered Methylation Patterns

Particular attention was given to the gene S100A8, which plays a key role in the innate immune response. While in vitro experiments showed a progressive decrease in methylation with repeated infections, clinical samples from children with asthma—based on data from the DZL’s ALLIANCE cohort—revealed an opposite trend with increased methylation.

The study provides important insights into how early viral infections may influence the risk of developing chronic airway diseases such as asthma. The results show that not only immune cells but also epithelial cells are capable of developing a kind of memory.

Original publication: Risha MA, Reddy KD, Nemani SSP, et al. Epigenetic training of human bronchial epithelium cells by repeated rhinovirus infections. Allergy. 2024; 79: 3385-3400. doi:10.1111/all.16388