Long, S. AliceCerosaletti, KarenBollyky, Paul L.Tatum, MeganShilling, HeatherZhang, ShengZhang, Zhong-YinPihoker, CatherineSanda, SrinathGreenbaum, CarlaBuckner, Jane H.2020-05-202020-05-202010-02Long, S. A., Cerosaletti, K., Bollyky, P. L., Tatum, M., Shilling, H., Zhang, S., Zhang, Z. Y., Pihoker, C., Sanda, S., Greenbaum, C., & Buckner, J. H. (2010). Defects in IL-2R signaling contribute to diminished maintenance of FOXP3 expression in CD4(+)CD25(+) regulatory T-cells of type 1 diabetic subjects. Diabetes, 59(2), 407–415. https://doi.org/10.2337/db09-0694https://hdl.handle.net/1805/22822OBJECTIVE In humans, multiple genes in the interleukin (IL)-2/IL-2 receptor (IL-2R) pathway are associated with type 1 diabetes. However, no link between IL-2 responsiveness and CD4+CD25+FOXP3+ regulatory T-cells (Tregs) has been demonstrated in type 1 diabetic subjects despite the role of these IL-2–dependent cells in controlling autoimmunity. Here, we address whether altered IL-2 responsiveness impacts persistence of FOXP3 expression in Tregs of type 1 diabetic subjects. RESEARCH DESIGN AND METHODS Persistence of Tregs was assessed by culturing sorted CD4+CD25hi natural Tregs with IL-2 and measuring FOXP3 expression over time by flow cytometry for control and type 1 diabetic populations. The effects of IL-2 on FOXP3 induction were assessed 48 h after activation of CD4+CD25− T-cells with anti-CD3 antibody. Cytokine receptor expression and signaling upon exposure to IL-2, IL-7, and IL-15 were determined by flow cytometry and Western blot analysis. RESULTS Maintenance of FOXP3 expression in CD4+CD25+ Tregs of type 1 diabetic subjects was diminished in the presence of IL-2, but not IL-7. Impaired responsiveness was not linked to altered expression of the IL-2R complex. Instead, IL-2R signaling was reduced in Tregs and total CD4+ T-cells of type 1 diabetic subjects. In some individuals, decreased signal transducer and activator of transcription 5 phosphorylation correlated with significantly higher expression of protein tyrosine phosphatase N2, a negative regulator of IL-2R signaling. CONCLUSIONS Aberrant IL-2R signaling in CD4+ T-cells of type 1 diabetic subjects contributes to decreased persistence of FOXP3 expression that may impact establishment of tolerance. These findings suggest novel targets for treatment of type 1 diabetes within the IL-2R pathway and suggest that an altered IL-2R signaling signature may be a biomarker for type 1 diabetes.en-USAttribution-NonCommercial-NoDerivatives 4.0 InternationalIL-2R SignalingRegulatory T-CellsType 1 Diabetic SubjectsFOXP3 inductionCytokine receptor expressionIL-2R pathwayBiomarkersArticle