Modulation of Host miRNAs by Intracellular Bacterial Pathogens

Abstract

MicroRNAs (miRNAs) are short non-coding RNAs that regulate the expression of protein coding genes of viruses and eukaryotes at the post-transcriptional level. The eukaryotic genes regulated by miRNAs include those whose products are critical for biological processes such as cell proliferation, metabolic pathways, immune response, and development. It is now increasingly recognized that modulation of miRNAs associated with biological processes is one of the strategies adopted by bacterial pathogens to survive inside host cells. In this review, we present an overview of the recent findings on alterations of miRNAs in the host cells by facultative intracellular bacterial pathogens. In addition, we discuss how the altered miRNAs help in the survival of these pathogens in the intracellular environment.

Keywords: Francisella; Listeria; Mycobacterium; Salmonella; host; macrophages; microRNA; regulation.

Figure 1

Schematic illustrating the miRNAs altered by Mycobacteria, Salmonella, Listeria and Francisella in relation to their cellular functions. The functions are grouped under three major categories such as macrophage defense, immune response and other related processes. Only very few miRNAs altered by these pathogens have shown common cellular functions and this includes miR-155. MiRNAs altered by specific pathogen(s) and their color(s) are as follows: Black-Mycobacteria; Blue-Listeria; Light Red- Mycobacteria and Listeria; Deep Red-Salmonella; Green-Mycobacteria, Salmonella, Listeria and Francisella.