Novel function of GATA-3, revealed by conditional deficient mice

GATA-3 is a zinc finger protein that is preferentially expressed in T cells in adult animals. Previous studies have shown that GATA-3 is essential for the transition from common lymphoid precursors to the most immature thymocytes. In addition, GATA-3 is selectively expressed in Th2 cells. Overexpression of GATA-3 forced developing Th1 cells to produce Th2 cytokines, including IL-4, IL-5, and IL-13. However, it remains unclear whether GATA-3 is also important at the later stages of T-cell development. Nor do we understand whether GATA-3 is essential for the differentiation of Th2 cells or for the maintenance of the Th2 phenotype. The lack of GATA-3-deficient mice or T cells has precluded further studies to address these important questions. We have recently generated conditional GATA-3-deficient mice. Studies on the conditional GATA-3-deficient mice has uncovered several novel roles of GATA-3 in regulating the development and function of T cells.