Fig. 3

MiR21 induced ICOS expression on Treg cells through p-STAT3 upregulation. a Treg cells were sorted from the co-culture system for further study, ICOS expression on Treg cells was increased by miR21 overexpression in the co-culture systems of SU-DHL-4 and SU-DHL-8 cells. b The effect of miR21 on transcriptional activity of the PDCD4 promoter was measured by luciferase reporter assay in HEK-293 T cells transfected with control mimics or miR21 mimics. c Downregulation of PDCD4 and upregulation of p-STAT3 were detected in Treg cells. d Increased ICOS expression on Treg cells was blocked by the STAT inhibitor (Representative immunofluorescene images of ICOS (green)/ICOSL (red) with cells counterstained with DAPI (blue))