IL3

Interleukin 3, or IL-3, emerges from activated T cells and NK cells, with supplementary sources like IL-1-activated endothelial cells, IgE-activated mast cells, and placental cells. By latching onto its receptor components—the α chain (IL-3Rα) and β chain (IL-3Rβ, CD131)—IL-3 sets off a signaling network that activates Janus kinases, especially JAK2, prompting STAT5 phosphorylation. This phosphorylated STAT5 then migrates to the nucleus to modulate gene transcription. IL-3 also activates the Ras-MAPK and PI3K pathways, establishing it as a pivotal hematopoietic growth factor that guides the maturation of cell types from granulocytes to mast cells, and plays a role in immune response, inflammation, and the management of blood disorders.