CD122

CD122, also known as the Interleukin-2 receptor beta chain (IL-2Rβ), is a transmembrane protein that plays a crucial role in the immune system. It is a component of the high-affinity receptor for Interleukin-2 (IL-2), a cytokine essential for the growth, proliferation, and differentiation of lymphocytes, particularly T cells and natural killer (NK) cells.

The IL-2 receptor is a multichain complex. The CD122 subunit, along with CD25 (the IL-2 receptor alpha chain) and CD132 (the common gamma chain), forms the high-affinity IL-2 receptor. CD122 itself can also associate with CD132 to form an intermediate-affinity receptor for IL-15. This dual functionality highlights its importance in mediating signals for multiple cytokines that are vital for immune cell development and function.

Expression of CD122 is found on various immune cells, including activated T cells, NK cells, and some myeloid cells. Its presence on these cells makes them responsive to IL-2 and IL-15, thereby influencing key immunological processes such as immune surveillance, T cell activation and tolerance, and the cytotoxic activity of NK cells. Dysregulation of CD122 signaling has been implicated in various autoimmune diseases and immune deficiencies, making it a target of interest in immunological research and potential therapeutic interventions.