The deacetylase SIRT2 contributes to autoimmune disease pathogenesis by modulating IL-17A and IL-2 transcription

Aberrant expression of IL-17A together with abated IL-2 production by effector CD4+ T cells contributes to the pathogenesis of systemic lupus erythematosus (SLE). Here we report that Sirtuin 2 (SIRT2), a member of the family of NAD+-dependent histone deacetylases, suppresses IL-2 production by CD4+ T cells while it promotes their differentiation into Th17 cells. Mechanistically, we show that SIRT2 is responsible for the deacetylation of p70S6K and the activation of the mTORC1/HIF-1α/RORγt pathway and the generation of Th17 cells differentiation. Additionally, SIRT2 is responsible for the deacetylation of c-Jun and histones on the Il-2 gene, resulting in decreased IL-2 production. We found that the transcription factor inducible cAMP early repressor (ICER), which is overexpressed in T cells from people with SLE and lupus-prone mice, binds directly to the Sirt2 promoter and promotes its transcription. AK-7, a SIRT2 inhibitor limited the ability of adoptively transferred antigen-specific CD4+ T cells to cause autoimmune encephalomyelitis and disease in the lupus-prone MRL/lpr mice. Finally, CD4+ T cells from SLE patients exhibited increased expression of SIRT2, and pharmacological inhibition of SIRT2 in primary CD4+ T cells from patients with SLE attenuated their ability to differentiate into Th17 cells and promoted IL-2–producing T cells. Collectively, these results suggest that SIRT2-mediated deacetylation is essential for the aberrant expression of IL-17A and IL-2 and that SIRT2 may be a promising molecular target for new therapies for SLE. mRNA profiles of CRIPSR/Cas9 enabled Sirt2 KO and control murine Th17 cells