Interleukin-2

Various cellular components are produced from bone marrow by various pathways for the different functions in our body. Cytokine or interleukin is involved in immune and non-immune cell functions. Interleukin-2 (IL-2) is a glycosylated globular protein and it is involved in the functions of lymphocytes under the Class I cytokine receptor family. Interleukin receptor (IL-2Rαβγ) is a trimeric complex binding to the interleukin-2 (IL-2) to initiate the various signaling pathway such as the STAT signaling pathway, the phosphoinositide 3-kinase (PI3K-AKT) signaling pathway, and the mitogen-activated protein kinase (MAPK) signaling pathway for the proliferation, differentiation, activation, and cytokine production in various immune cells. In various clinical conditions like acute respiratory distress syndrome, candidiasis, acute allograft rejection, tuberculosis, hemophagocytic lymphohistiocytosis, granulomatous diseases, autoimmune diseases, malignant diseases, sarcoidosis, etc., interleukin-2 acts as a biomarker. The cytokine-like interleukin-2 is mainly applied in cancer therapy as a monotherapy or as a combination—with other cytokines, other cell-based immunotherapy, chemotherapeutic agents, and peptide vaccines. The biological activity of human recombinant IL-2 (rIL-2) is used in metastatic carcinoma and also in patients with various conditions, notably HIV, tuberculosis, and autoimmune diseases. Interleukin-2 therapy shows toxicities such as vascular leak syndrome (VLS), etc. The two novel IL-2 mutants, namely F42K and R38A can activate LAK cells without the production of high levels of pro-inflammatory cytokine (IFNg, IL-1b, TNF-a) and prevent vascular leak syndrome (VLS). Future clinical research needs facts about the timing and dose of the new therapeutic agent with or without combination, the mechanism of IL-2R and lymphocytes, etc.