JAK3 Janus kinase is involved in interleukin 7 signal pathway

Abstract
Interleukin (IL) 7 is an important cytokine regulating both T and B cell development and inducing the formation of lymphokine‐activated killer cells and cytolytic T lymphocytes. This study reports the role of JAK family kinases in the IL‐7 signalling pathway in a T cell clone. The results have shown that out of 4 members of JAK family tyrosine kinases (JAK1, JAK2, JAK3 and Tyk2), only JAK3 was tyrosine‐phosphorylated and activated in cells of a T cell clone by stimulation with IL‐7. Furthermore, STAT1α (STAT, the signal transducers and activators of transcription) and p44 of MAPK (mitogen‐activated protein kinases) were tyrosine phosphorylated by IL‐7 stimulation, indicating that the two signal pathways might be involved in IL‐7 signal transduction.