While Il12 p40 was not influenced, quantitative PCR analysis showed an increased Il12 p35 mRNA level in miR 21 inhibitor transfected BMDCs. Consistently, miR 21 mimics Il12 p35 mRNA expression and further paid off IL 12p70 protein level. We then infected BMDCs in vitro by BCG, and analyzed the expression of endogenous IL 12 and miR 21 mRNA expression at different time points. MiR 21 and both IL 1-2 mRNA were upregulated following infection. Nevertheless, IL 12 transcription increased tens of folds only 1 h after infection, reaching its peak between 4 and 6 h, while miR 21 increased slowly and only slightly following infection, and this increase became more significant after 6 h. Over all, miR common compound library 21 was negatively correlated with IL 12p35 mRNA expression, suggesting posttranscriptional regulation of Il12p35 by miR 21. We also examined the expression of TNF, IL 6, IL 1b and IL 10 release in miR 21 chemical transfected BMDCs and weighed against control transfected BMDCs, as recent studies suggested to get a protective function of TNF, IL 6 and IL 1b in host resistance to Mtb disease, while IL 10 generally suppresses anti mycobacterial reactions. We observed slightly IL 6, elevated expression of TNF and IL 1b in BMDCs inhibited of miR 21. Meristem Nevertheless, no significant change was seen in IL 10 expression. However when these BMDCs were co cultured with antigen specific T cells, somewhat improved IL 10 production was observed. Reports also suggested that mycobacteria disease may produce IFN h production in DCs by targeting TLRs, which may function in an autocrine fashion to excellent DCs them-selves. Although STAT4 and IL 1-2 are recommended to be responsible for inducing IFN c in DCs, nevertheless, the IFN c appearance by BMDCs was indeed low and showed no big difference after miR 21 inhibition. Via a bioinformatics search using PicTar and TargetScan, we found that the 30UTR of Il12p35 mRNA provides the miR 21 binding web sites that are extremely conserved in mammals. Moreover, Il6, Tnf, Il12p40 and Il1b mRNA weren’t specifically contained in the predicted miR 21 goals, suggesting for Decitabine solubility other mechanisms involved with miR 21 mediated reduction of these cytokines. A double luciferase reporter assay was used, to examine the likelihood that IL 1-2 is regulated post transcriptionally by miR 21. Once the reporter plasmid containing the Il12p35 30UTR was company transfected with miR 21 mimics luciferase expression markedly reduced. More over, this decrease was abrogated by transfection of a containing a three base mutation in-the miR 21 binding site. Luciferase activity was also significantly suppressed by mir 21 in BMDCs, even after exciting of BCG. These data indicate that miR 21 can inhibit IL 12 production by directly targeting the 30UTR of Il12p35 mRNA. The above results suggested that miR 21 could downregulate IL12 together with TNF and IL 6.