IL2S

Il2s is a gene that encodes a small membrane protein involved in the regulation of T‑cell signaling in mammals. The IL2S protein is a type‑I transmembrane protein of approximately 190 amino acids that is glycosylated on its extracellular domain. It is detected primarily in activated T lymphocytes and is up‑regulated following stimulation with interleukin‑2 and other growth factors. The protein contains a single extracellular Ig‑like domain that is thought to mediate homodimerization and interaction with other components of the interleukin‑2 receptor complex, including the β and γc subunits.

The functional role of IL2S appears to be modulatory rather than catalytic. In vitro studies have shown that knockdown of Il2s expression in T‑cell lines reduces proliferation and down‑regulates interleukin‑2 production, suggesting that IL2S enhances signal transduction downstream of the IL‑2 receptor. Conversely, overexpression leads to increased cellular responsiveness to IL‑2 and can amplify cytokine release. In vivo, mice with targeted deletion of Il2s display mild immunoregulatory abnormalities, including a lower frequency of regulatory T cells and decreased capacity to respond to antigenic challenge.

Because of its involvement in immune modulation, Il2s has been examined as a potential therapeutic target in autoimmune and inflammatory diseases. Preclinical studies using IL2S‑antagonistic antibodies have shown attenuation of disease severity in mouse models of experimental colitis and autoimmune encephalomyelitis. However, clinical trials are still in early phases and the safety profile of IL2S modulation has not yet been conclusively established.

Ongoing research aims to clarify the precise receptor interactions and downstream signaling pathways that IL2S engages, with the goal of determining whether selective modulation of this protein could offer advantages over conventional cytokine therapy.