Regulation of the interleukin 2 and interleukin 4 genes in murine T helper 1 and T helper 2 cell clones

Murine T helper cell clones are classified into two distinct subsets, T helper 1 (Th1) and T helper 2 (Th2), on the basis of cytokine secretion patterns. Th1 clones produce interleukin-2 (IL-2), tumor necrosis factor-;Of the genes expressed by Th2 clones, IL-4 is perhaps the most influential. IL-4 is the major cytokine involved in promoting B cell-mediated immune responses, and is critically required for Th2 responses such as those associated with infection with metazoan parasites. IL-4 also promotes the development and growth of Th2 cells, while inhibiting Th1 cell differentiation. How the IL-4 gene is transcriptionally regulated remains largely unknown. This thesis is involved primarily in identifying and characterizing the transcription factors responsible for the regulation of the IL-4 gene.;In contrast to IL-4, the promoter of the Th1-specific cytokine, IL-2, is perhaps one of the most characterized mammalian promoters. In the course of studying the IL-4 promoter, many of the transcription factors identified in regulating this gene also had been shown to be involved in regulating the IL-2 promoter. The role of these common factors in IL-2 and IL-4 expression was analyzed in more depth, and constitutes the remaining part of this thesis.