Regulation of the Human Interleukin-3 Gene

Interleukin-3 (IL-3), a cytokine, expression is induced in response to stimulation due to an infection or the presence of foreign substances in the body. Once the infection or substance is cleared from the body, IL-3 expression is turned off. IL-3 is only expressed in small subset of cells of the immune system such as T and mast cells. This work describes the genetic elements such as enhancer, repressor and locus control regions that might be involved in this highly specific expression pattern. Moreover, the IL-3 locus is located close to the GM-CSF (another cytokine) gene which has a wider range of cell specificity. This book describes genetic elements situated between the two genes which were hypothesized as a boundary element protecting the IL-3 gene from being induced to be expressed inappropriately by the GM-CSF enhancer and to insure the cell type and temporal expression specificity of the IL-3 gene.