MicroRNA Interference in Hepatic Host-Pathogen Interactions

The liver is well recognized as a non-immunological visceral organ that is involved in various metabolic activities, nutrient storage, and detoxification. Recently, many studies have demonstrated that resident immune cells in the liver drive various immunological reactions by means of several molecular modulators. Understanding the mechanistic details of interactions between hepatic host immune cells, including Kupffer cells and lymphocytes, and various hepatic pathogens, especially viruses, bacteria, and parasites, is necessary. MicroRNAs (miRNAs), over 2600 of which have been discovered, are small, endogenous, interfering, noncoding RNAs that are predicted to regulate more than 15,000 genes by degrading specific messenger RNAs. Several recent studies have demonstrated that some miRNAs are associated with the immune response to pathogens in the liver. However, the details of the underlying mechanisms of miRNA interference in hepatic host–pathogen interactions still remain elusive. In this review, we summarize the relationship between the immunological interactions of various pathogens and hepatic resident immune cells, as well as the role of miRNAs in the maintenance of liver immunity against pathogens.