IL-2 is secreted by

IL-2 is a typical four a helix cytokine and is produced primarily by activated CD4+ T cells, although expression by naive CD8+ T cells, dendritic cells, and thymic cells has also been repoed (8, 9, 10, 11). In T cells, IL-2 synthesis is tightly regulated at the mRNA level by signals from the TCR and CD28 (12).