Regulation of human immunodeficiency virus 1 transcription by nef microRNA

Molecular Biology and Retroviral Genetics Group, Division of Nutritional Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan Correspondence Yoichi R. Fujii fatfuji{at}hotmail.com MicroRNAs (miRNAs) are 21–25 nt long and interact with mRNAs to lead to either translational repression or RNA cleavage through RNA interference. A previous study showed that human immunodeficiency virus 1 (HIV-1) nef dsRNA from AIDS patients who are long-term non-progressors inhibited HIV-1 transcription. In the study reported here, nef -derived miRNAs in HIV-1-infected and nef transduced cells were identified, and showed that HIV-1 transcription was suppressed by nef -expressing miRNA, miR-N367, in human T cells. The miR-N367 could reduce HIV-1 LTR promoter activity through the negative responsive element of the U3 region in the 5'-LTR. Therefore, nef miRNA produced in HIV-1-infected cells may downregulate HIV-1 transcription through both a post-transcriptional pathway and a transcriptional neo-pathway.