Cloning of the Mouse Interleukin 2 Receptor γ Chain: Demonstration of Functional Differences Between the Mouse and Human Receptors

Abstract

We isolated a cDNA clone for the γ chain of the mouse interleukin 2 receptor. Introduction of the mouse γ chain cDNA clone into a mouse fibroblast cell line, L929, expressing the mouse αβ heterodimer IL-2 receptor converted pseudohigh affinity of the IL-2 receptor into functional high, resulting in internalization of IL-2 and induction of the c-myc, cfos and c-jun genes. The mouse βγ heterodimer, however, failed to bind IL-2 unlike the human βγ heterodimer intermediate-affinity receptor. These results indicate that the mouse functional IL-2 receptor is a complex comprising three distinct subunits, α, β and γ chains, but the βγ heterodimer is not functional and different from the human heterodimer.