miRNAs: Key Molecules in the Immunopathogenesis of Betacoronaviruses

A series of patients hospitalized with acute respiratory disease was reported in Wuhan, Hubei Province, China, in December 2019. Many patients have had direct or indirect links with the Huanan Seafood Wholesale Market, Wuhan. This is the prologue to the ongoing pandemic of Coronavirus Disease 2019 (COVID-19) that has affected more than 150 countries and over 250,000 people worldwide, killing thousands of people. The pandemic has once again drawn public attention to the coronaviruses that developed epidemics in China (2002) and Saudi Arabia (2012). Given the structural and phylogenetic similarity of the 2019 novel coronavirus (2019-nCoV) with the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV), the results of recent studies have been combined with new findings to complete one of the strangest pneumonia puzzles in the human history. Coronaviruses establish extremely complex interactions with the immune system, especially in order to evade immune responses. Undoubtedly, increasing our knowledge of the immunopathogenesis of diseases caused by these viruses will eventually lead to more effective treatment and diagnosis. Non-coding RNAs (ncRNAs) are among the leading immune response regulators. MicroRNAs (miRNAs) play an important role in the expression and regulation of both innate and adaptive immune responses and in many immune disorders from autoimmunity to cancer and allergies. Our understanding of the functions of human and viral miRNAs in the pathogenesis of many viruses has increased in recent years. Accordingly, the present review article aims to review studies evaluating the role of miRNAs in the pathogenesis of other Betacoronaviruses. The results of these studies, given the similarity of viruses within the family Coronaviridae, could be helpful for future research on SARS-CoV-2.