Human Interleukin 2 Receptor Alpha (IL2RA) Protein

Background

Interleukin 2 receptor subunit alpha (IL2RA), also known as CD25, is a crucial component of the high-affinity interleukin-2 (IL-2) receptor complex, which is essential for regulating immune responses, particularly T-cell proliferation and survival. The IL-2 receptor plays a pivotal role in both adaptive immunity and immune tolerance, with IL2RA being one of the three subunits that form the IL-2 receptor complex. The IL-2 receptor system is critically involved in the regulation of T-cell homeostasis, immune activation, and the suppression of autoimmunity. IL2RA is primarily expressed on activated T cells, particularly regulatory T cells (Tregs), which are crucial for maintaining immune tolerance. It is also found on other immune cells, including activated B cells, dendritic cells, and natural killer (NK) cells under certain conditions. Importantly, IL2RA expression is tightly regulated, being upregulated upon T-cell activation and playing a central role in fine-tuning immune responses.