Chapter 15 MicroRNAs and the immune system

MicroRNAs (miRNAs/miRs) also known as small noncoding RNAs have emerged as crucial regulators in the modulation of the expression of multiple target genes at post-transcriptional level. Accumulating studies have provided compelling evidence that a wide range of miRNAs constitute an integrated part of the regulatory networks of immune response. Also, miRNAs contribute to normal immune system development and function. In particular, miRNAs can tightly regulate innate immune response by targeting key signaling components of inflammatory shapes such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and type I-III interferon (IFN-I-III) pathways. Moreover, they can finely modulate distinct immune signaling pathways involved in the T and B cell development, differentiation, tolerance (central and peripheral), and function. Taking these considerations into account, this chapter aims to describe current progress in miRNA research and to describe how these small noncoding RNAs can affect different innate and adaptive immune processes.