All living organisms are subjected to attack from disease-causing agents. Orchestrated response by various cell types (both immune and non-immune cells) confer protection against incessant invasion of microbes (harmful or innocuous) by recognizing and eliciting efficient immune response to contain and clear microbes. A key feature of immune cells is their ability to exhibit tremendous functional plasticity that allows them to elicit adept immune response. Equally significant is the role of immune cells in the resolution of inflammation. Subsequent to pathogen removal, immune cells should dampen inflammatory activities and switch to perform tissue repair functions, which in turn is attributed to their functional plasticity. Various genetic, environmental or pathogenic factors can cause aberrations in the immune cell function, polarization or inflammatory resolution leading to disease pathogenesis. Dysregulation of various genetic components has been associated with the development of immune related disorders, including autoimmune diseases. Evidently, multiple layers of molecular regulation control activation of immune response.

MiRNAs are known to control various aspects of immune response including immune signaling, immune cell differentiation and polarization. In addition to cellular miRNAs, ubiquitously secreted extracellular vesicles containing microRNAs are also acknowledged in shaping immune response/activation of recipient cells. Various pathogens, such as herpes simplex virus 1, human cytomegalovirus, etc., also encode microRNAs to counteract the host immune response. Numerous DNA viruses (predominantly herpesviruses) encode miRNAs that control virus tropism, life cycle and immune evasion.

This Research Topic aims to shed light on the role of miRNA in the recognition of various pathogens, activation of pro-inflammatory and anti-inflammatory immune pathways, differentiation and polarization of myeloid and lymphoid cells, and impact of miRNA expression profiles in infectious and inflammatory diseases (including but not limited to HIV-1, tuberculosis, rheumatoid arthritis). Additionally, studies on virus-derived microRNAs with a focus on their immune modulatory functions will also be included. We welcome the submission of Original Research articles, Reviews and Mini-Reviews covering, but not limited to, the following topics:

1. MiRNA in the regulation of immune signaling during infection and inflammation.
2. Transcriptional and post-transcriptional regulation of miRNAs in immune response.
3. MiRNA regulation of T cell and macrophage polarization and plasticity.
4. Role of miRNAs in immune cell interaction and activation during infection and inflammation.
5. Pathogen and environmental factor-mediated dysregulation of miRNA in immune response.
6. Viral-encoded miRNA in immune evasion and suppression.
7. Role of extracellular vesicles-contained microRNAs in shaping immune responses.

Keywords: microRNAs, immune signaling, polarization and plasticity, immune evasion, microRNA regulation in immunity, inflammatory and autoimmune diseases

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.