ReviewThe role of miR-155 in regulatory T cells and rheumatoid arthritis

- CTLA-4 expression on Tregs from RA patients is reduced compared with healthy Treg.
- Induced expression of CTLA-4 in RA Tregs restores their suppressive capacity.
- miR-155 is deregulated in RA and targets CTLA-4 gene expression.
- In this review we illustrate the role of miR-155 in Tregs.
- Eventually we discuss the potential impact of therapeutic miR-155 modulation in RA.

Recently, various micro(mi)RNAs have been found deregulated in the setting of rheumatoid arthritis (RA), but their role in the pathogenesis of this disease remains a matter of debate. In the meanwhile, increasing evidence indicates a defective function of regulatory T cells (Tregs) in RA. This review discusses relevant studies addressing the function of Tregs and Cytotoxic T-Lymphocyte Antigen 4 in RA, provides recent data on the role of miRNAs for Tregs homeostasis, and focuses on the role of miR-155 in Tregs. In a final perspective section we discuss the potential impact of therapeutic miR-155 modulation in RA.