Regulation of human immunodeficiency virus 1 transcription by nef microRNA.

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.