BROAD TRANSCRIPTIONAL FIRING REPRESSES BACTERICIDAL ACTIVITY IN HUMAN AIRWAY NEUTROPHILS

In chronic diseases such as cystic fibrosis (CF), an unexplained paradox pits massive neutrophil presence against prolonged bacteria infections. Here, we show that neutrophils recruited to CF airways in vivo and in an in vitro transmigration model display rapid and broad transcriptional firing, leading to an upregulation of survival and anabolic genes, and a downregulation of antimicrobial genes.

Newly transcribed RNAs are mirrored by the appearance of corresponding proteins, confirming active translation in these cells. Remarkably, treatment by the RNA polymerase II and III inhibitor -amanitin restored expression of key antimicrobial genes, and increased bactericidal capacity of CF airway neutrophils in vitro and in short-term sputum cultures ex vivo. Broadly, our findings show that neutrophil plasticity is regulated at the terminal organ via RNA and protein synthesis, leading to adaptations that profoundly impact their canonical functions (i.e., bacterial clearance).