The role of microRNAs in bacterial infections

Abstract The immune response to bacterial pathogens is designed to contain infection by triggering signaling pathways which regulate inflammation, autophagy, and cell death. The innate immune response is initiated when a set of pathogen-associated molecular patterns (PAMPs) engage surface-associated or intracellular pattern recognition receptors (PRRs) of antigen-presenting cells. The resulting activation of transcription factors such as NF-κB culminate in the expression of mediators of inflammation, leukocyte recruitment, invasion, and processes, which are central to containing the pathogen. Pathogens, on the other hand, often hijack this machinery to facilitate their own survival and replication within the host intracellular niche. MicroRNAs (miRNAs) are intimately involved in the posttranscriptional regulation of the above mentioned immune response. Here, we review the current knowledge on how bacterial pathogens modulate host miRNAs. We restrict ourselves to how miRNAs rewire the immune response to restrict inflammation and autophagy, which are two responses intimately connected to how the host responds to bacterial challenge.