Roles of microRNAs in HIV-1 Replication and Latency.

MicroRNAs (miRNAs) are non-coding RNA molecules, with sequence length of 19-24 nucleotides, which can induce mRNA degradation and regulate protein translation repression. Recently plenty of reports showed that miRNAs increase or decrease in the serum (circulating miRNAs) and in PBMC of Human immunodeficiency virus type 1 (HIV-1) infected individuals to affect the replication of HIV-1 through regulating HIV-1 proteins or HIV-1 replication related host factors. Many of miRNAs can suppress HIV-1 replication, but do not affect the integrated viral DNA. Low or no viral protein expression could result in a block of virus and its replication to induce HIV-1 latency, which is the great obstacle of the cure of HIV-1 infection. In the HIV-1 latency reservoir, the integrated provirus can reactivate under appropriate stimulus, which results in HIV-1 reproduction. Factors imply that cellular miRNAs may promote the establishment of HIV-1 latency. Further studies on the mechanisms of miRNAs affecting viral protein expression will provide new approaches to clear the viral reservoir.