Provided herein are IL-2 muteins, IL-2 mutein Fc-fusion molecules, anti-IL-2 antibodies, and complexes comprising an anti IL-2 antibody bound to an IL-2 cytokine that preferentially expand and activate T regulatory cells and are amenable to large scale production. Also provided herein are variant human IgG1 Fc molecules lacking or with highly reduced effector function and high stability despite lacking glycosylation at N297. Also provided herein are linker peptides that are glycosylated when expressed in mammalian cells. Also provided herein are methods of making and using the compositions of the present invention.