Glycosylation-dependent modulation of the IL-2 signaling axis determines Th17 differentiation and IL-10 production

Metabolism plays an essential role in shaping Th cell responses including the production of pro-inflammatory cytokines. However, its effect on the production of the anti-inflammatory cytokine IL-10 has not been investigated. We show here that the glucose analogue 2-deoxyglucose (2DG) specifically inhibited Th1 and Th2 cell differentiation and accompanying IL-10 production. In contrast, 2DG promoted IL-17A production by Th17 cells, even in the presence of IL-2 known to limit Th17 differentiation, whilst simultaneously also abrogating the production of IL-10. Rather than inhibiting glycolysis, 2DG was found to act through the inhibition of glycosylation, itself critical for IL-2Ra surface expression and downstream signaling, explaining the reciprocal effect of 2DG on the Th1 and Th2 versus Th17 differentiation. The essential role of IL-2 for IL-10 production by Th17 cells was confirmed by adding IL-2 or anti-IL-2, neither of which made the cells more pathogenic. The molecular mechanism of the IL-2 driven Th17 IL-10 production may be attributed to the transcription factor c-Maf, whose expression was significantly upregulated in the presence of IL-2 signaling. The overall RNA signature of sorted IL-10+ T cells driven by IL-2, be it IL-17A+ or IL-17A-, was dominated by protein synthesis whereas that of their IL-10- counterparts by cell cycle associated processes suggesting that IL-10 secreting Th17 cells trade off self-renewal for secretory capacity. Our study thus reveals a previously unappreciated, anti-inflammatory role for IL-2 in Th17 cell production of IL-10 and identifies a novel mechanism to limit Th17 pathogenicity. RNA-Seq on in-vitro differentiated Th17 cells in the presence of added IL-2 or anti-IL-2 antibody, all cells or cells sorted into different IL-17A/IL-10 secreting T cells following intracellular cytokine staining