Mechanism Of MiR-146a Regulates Macrophage-Associate Innate Immunity During HIV-1 Infection

Objective:miR-146a is a kind of post-transcriptional regulator,which regulates gene expression by binding to complementary sites presented in the 3'-UTR of target gene via their seed regions.A number of researches have exhibited miR-146a as a negative regulator in innate immune,inflammatory response and antiviral pathway can suppress the expression of IRAK1 and TRAF6,attenuate NF-?B activity and impair NF-?B down-stream genes.However,the definitely function of miR-146a in HIV-1 infection is poorly understood.To illuminate the expression kinetics and specific function of miR-146a in host immune response during HIV-1 infection is the objective of this study.Methods:RT-qPCR was used to determine the expression of HIV-1 Gag,miR-146a and CCL5,respectively.Luciferase assay was used to determine the effect of miR-146a on the target genes.ELISA was performanced to determine the release level of CCL5.Finally,We further investigated whether down-regulation of CCL5 by miR-146a could affect monocytes migration by THP-1 chemotaxis assay.Results:We found that miR-146a was significantly up-regulated during HIV-1 infected and polyI:C stimulation,while CCL5 were induced in early infection phase but reduced during later phase in human primary macrophages.We have also provided evidences that miR-146a could target CCL5 and HIV-1 Gag which evaluated by 3'UTR reporter assays.Moreover,we verified that overexpression of miR-146a down-regulates expression and release levels of CCL5,while inhibition of miRNA-146a increases expression and release levels of CCL5 in macrophages during HIV-1 infection and polyI:C stimulation.Finally,we further proved that down-regulation of CCL5 by miR-146a could affect monocytes migration by THP-1 chemotaxis assay.Conclusion:We presented here the evidences that miR-146a targets CCL5 and down-regulates it's release in macrophages,consequently,affects monocytes migration.These studies further our understandings of the mechanisms and regulations of miR-146a during HIV-1 infection and polyI:C stimulation.It is possible that miR-146a could become the potentially useful therapeutic target for the treatment of HIV infection or RNA virus.