Respiratory Epithelial Cells Can Remember Infection: A Proof of Concept Study.

Human bronchial epithelial cells play a key role in airway immune homeostasis. We hypothesized that these sentinel cells can remember a previous contact with pathogen compounds and respond nonspecifically to reinfection, a phenomenon called innate immune memory. We demonstrated that their pre-exposure to Pseudomonas aeruginosa flagellin modify their inflammatory response to a second, non-related stimulus, including live pathogens or lipopolysaccharide. Using histone acetyltransferase and methyltransferase inhibitors, we showed that this phenomenon relied on epigenetic regulation. This report is a major breakthrough in the field of multi-microbial respiratory tract infections, wherein control of inflammatory exacerbations is a major therapeutic issue.