mi RNA s and HIV : unforeseen determinants of host‐pathogen interaction

Summary Our understanding of the complexity of gene regulation has significantly improved in the last decade as the role of small non‐coding RNA s, called micro RNA s (mi RNA s), has been appreciated. These 19–22 nucleotide RNA molecules are critical regulators of mRNA translation and turnover. The mi RNA s bind via a protein complex to the 3′ untranslated region (3′ UTR ) of mRNA , ultimately leading to mRNA translational inhibition, degradation, or repression. Although many mechanisms by which human immunodeficiency virus‐1 ( HIV ‐1) infection eventually induces catastrophic immune destruction have been elucidated, the important role that mi RNA s play in HIV ‐1 pathogenesis is only now emerging. Accumulating evidence demonstrates that changes to endogenous mi RNA levels following infection is important: in maintaining HIV ‐1 latency in resting CD 4 + T cells, potentially affect immune function via changes to cytokines such as interleukin‐2 ( IL ‐2) and IL ‐10 and may predict disease progression. We review the roles that both viral and host mi RNA s play in different cell types and disease conditions that are important in HIV ‐1 infection and discuss how mi RNA s affect key immunomodulatory molecules contributing to immune dysfunction. Further, we discuss whether mi RNA s may be used as novel biomarkers in serum and the potential to modulate mi RNA levels as a unique approach to combating this pathogen.