IL2RA

IL2RA (Interleukin 2 Receptor Alpha), also known as CD25, is a protein that in humans is encoded by the IL2RA gene. This gene is a part of the immune system and plays a critical role in the regulation of T cell function. The IL2RA protein is a component of the high-affinity IL2 receptor complex, which is important for the immune response to pathogens and for maintaining self-tolerance.

Structure

The IL2RA gene encodes the alpha chain of the interleukin 2 receptor. This receptor chain is necessary for the interleukin 2 (IL-2) signaling pathway. The alpha chain, when combined with the beta (CD122) and gamma (CD132) chains, forms the high-affinity IL2 receptor. Alone, the alpha chain has low affinity for IL-2, but when part of the high-affinity receptor, it allows for effective signaling in T cells.

Function

IL2RA is primarily expressed on regulatory T cells (Tregs) and activated T cells. It plays a crucial role in the immune system by regulating the growth, proliferation, and differentiation of T cells. The binding of IL-2 to its receptor initiates a signaling cascade that promotes T cell survival and proliferation. This is essential for the immune system's ability to respond to antigens and for the maintenance of tolerance to self-antigens.

Clinical Significance

Alterations in the expression or function of IL2RA have implications in several autoimmune diseases, such as Type 1 diabetes, multiple sclerosis, and rheumatoid arthritis. Elevated levels of soluble IL2RA have been observed in the serum of patients with these diseases, suggesting a role in disease pathogenesis.

In addition, the IL2RA gene is a target for immunosuppressive drugs used in organ transplantation and in the treatment of autoimmune diseases. Blocking the IL-2/IL2RA interaction can reduce T cell proliferation, thereby suppressing the immune response.

Genetics

The IL2RA gene is located on the short arm of chromosome 10 (10p15.1). Variants within or near this gene have been associated with susceptibility to various autoimmune conditions, highlighting its importance in immune regulation.

Research

Research on IL2RA continues to uncover its roles in immune function and its potential as a therapeutic target in immune-related diseases. Studies are exploring how modulating IL2RA expression and function can benefit the treatment of autoimmune diseases and enhance cancer immunotherapy strategies.