This will be a randomized, controlled, double blinded, multicenter, phase I/II clinical trial to evaluate the safety of low-dose IL-2 and to test whether low-dose IL-2 can prevent further loss of beta-cell function in patients with established T1D, or even potentially improve ß-cell function in such individuals, when IL-2 is given for one year (primary outcome). Equally important, the study will carefully examine various effects of low-dose IL-2 on the immune system in patients with T1D, including effects on Treg and other cell subsets, and disease-specific autoimmune responses.