MicroRNA Response of Primary Human Macrophages to Arcobacter Butzleri Infection

The role of microRNAs (miRNAs) in infectious diseases is becoming more and more apparent, and the use of miRNAs as a diagnostic tool and their therapeutic application has become the major focus of investigation. The aim of this study was to identify miRNAs involved in the immune signaling of macrophages in response to Arcobacter (A.) butzleri infection, an emerging foodborne pathogen causing gastroenteritis. Therefore, primary human macrophages were isolated and infected, and miRNA expression was studied by means of RNAseq. Analysis of the data revealed the expression of several miRNAs, which were previously associated with bacterial infections such as miR-155, miR-125, and miR-212. They were shown to play a key role in Toll-like receptor signaling where they act as fine-tuners to establish a balanced immune response. In addition, miRNAs which have yet not been identified during bacterial infections such as miR-3613, miR-2116, miR-671, miR-30d, and miR-629 were differentially regulated in A. butzleri-infected cells. Targets of these miRNAs accumulated in pathways such as apoptosis and endocytosis – processes that might be involved in A. butzleri pathogenesis. Our study contributes new findings about the interaction of A. butzleri with human innate immune cells helping to understand underlying regulatory mechanisms in macrophages during infection.