Human Interleukin 2 (IL-2) Promotion of Immune Regulation and ClinicalOutcomes: A Review

Interleukin 2 (IL-2) is a monomeric glycoprotein that is primarily produced by activated CD4+ T cells, CD8+ T cells and dendritic cells. It is characterized as a proinflammatory cytokine that is secreted by Th1 cells. IL-2 plays a central role in the activation of regulatory T cells to produce the cytokines tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). IL-2 may also enhance the cytolytic activity of natural killer cells, thereby ensuring their significance in the control of the immune response, and effectively participate in the pathogenesis of several pathological conditions, such as cancer and metabolic, infectious, autoimmune and inflammatory diseases. We emphasize the importance of studies of IL-2 and discuss perspectives resulting from our increasing understanding of genetic diversity and its role in the immune response.