Cell type-specific enhancer element associated with a mouse MHC gene, E beta.

Class II molecules of the major histocompatibility complex (MHC) are heterodimeric glycoproteins expressed on the surface of antigen-presenting B lymphocytes and macrophages. The genes encoding the alpha- and beta-chains of the class II heterodimers, A alpha A beta and E alpha E beta, have recently been characterized at the molecular level, and certain cloned genes were shown to be functionally expressed after introduction into cells by DNA-mediated gene transfer. One study found that a transfected Eb beta gene was expressed in a macrophage cell only after treatment of cells with gamma-interferon. DNA sequences associated with transfected Class II MHC genes may therefore have a regulatory role in their cell type-specific expression. We report here the identification of a cell type-specific transcriptional enhancer element associated with the mouse Ed beta gene.