IL-2 R beta & IL-15 R alpha & IL-2 R gamma

Interleukin-2 receptor beta (IL-2Rβ, CD122) and the common gamma chain (γc, CD132) constitute the shared signaling modules for IL-2 and IL-15. IL-15 receptor alpha (IL-15Rα, CD215) is a specific high-affinity binding chain for IL-15. Its sushi domain mediates tight binding, and it can be shed as a soluble form. Unlike classical cytokine receptors, IL-15Rα often presents IL-15 in trans to adjacent cells expressing IL-2Rβ/γc, a process essential for the development, survival, and proliferation of natural killer (NK) cells and memory CD8+ T cells. IL-2 utilizes IL-2Rα, IL-2Rβ, and γc for high-affinity signaling. These three chains are members of the common gamma chain family. γc associates with JAK3, while IL-2Rβ recruits JAK1, both activating the STAT5 pathway to regulate immune responses.