Protein Kinase A Regulates GATA-3-Dependent Activation of IL-5 Gene Expression in Th2 Cells

Abstract

Treatment of Th cells with compounds that elevate cAMP levels augments Th2-type lymphokine expression, in particular the synthesis of IL-5. Using primary murine CD4+ T lymphocytes, we show in this study that inhibition of protein kinase A (PKA) activity in Th2 effector cells impairs IL-5 synthesis, whereas the expression of PKA catalytic subunit α enhances IL-5 synthesis in Th0 cells. In addition, we observed by coexpression of PKA catalytic subunit and GATA-3 in Th1 cells that the stimulatory effect of PKA is dependent on GATA-3 activity. These data demonstrate that activation of PKA in Th effector cells induces the IL-5 gene expression in a GATA-3-dependent manner.