What controls tissue-specific expression of the IL-4 gene?

Interleukin-4 (IL-4) plays a central role in the pathogenesis of allergic inflammation Ly inducing Ig class switch to IgE. IL-4 is also the most potent factor that drives naive T helper (Th) cells to differentiate to the Th2 phenotype. Recently, efforts have been made to explore the molecular basis of the Th2-specific IL-4 expression in CD4 T cells. Transcription factors,such as GATA-3, NF-IL6 and c-Maf, were found to be preferentially expressed in Th2 cells and to play an important role in regulation of the IL-4 promoter activity. Yet, other transcription factors may be indirectly involved in Th2-specific expression of IL-4 even though they are present in both Th1 and Th2 cells. In conclusion, Th2-specific expression of the IL-4 gene appears to be controlled by a multi-factor-system.