Self-tolerance gene?

CD4⁺ regulatory T cells suppress self-reactive lymphocytes and control immunological self-tolerance. Their role is thought to be important in the etiology autoimmune diseases, but the molecular mechanisms and genes involved in the development of these regulatory T (TR) cells have been unclear. In the January 9 Sciencexpress, Shohei Hori and colleagues at The Institute for Physical and Chemical Research (RIKEN), Yokohama, Japan, show that the transcription factor gene FOXP3 controls TR cell development (Sciencexpress, 10.1126/science.1079490, January 9, 2003).

Hori et al. tested the thymus and periphery of normal mice for the transcription factor gene Foxp3 — defective in an autoimmune/inflammatory syndrome in humans and mice. They observed that Foxp3 mRNA is specifically expressed in naturally arising CD4⁺ TR cells. In addition, they showed that retroviral gene transfer of Foxp3 converts naïve T cells towards a TR cell phenotype similar to naturally occurring CD4^+...