In these studies, we have identified DNA sequences and specific protein interactions necessary for transcriptional regulation of the human prointerleukin 113 (proIL-i1i) gene. A cell-type-independent lipopolysaccharide (LPS)-responsive enhancer element located between -3757 and -2729 bp upstream from the transcription start site (cap site) consisted of at least six discrete subregions which were essential to the maximal induction by LPS in transfected monocytes. The enhancer also appeared to mediate phorbol myristate acetate induction in monocytes and IL-1 responsiveness in fibroblasts. Deletion and base substitution mutations along with DNA binding studies demonstrated that the enhancer contained a minimum of three functional protein binding sequences, two of which appeared to be important for gene induction. One of the essential proteins which bound to the enhancer was similar or identical to members of the C/EBP family of transcription factors required for both IL-1-and LPS-specific induction of the IL-6 gene (i.e., the NF-IL6 proteins). When ligated to the proIL-1l3 cap site-proximal region (located between -131 to +12), both the proIL-1,3 and the simian virus 40 enhancer elements functioned more efficiently in monocytes than in HeLa cells, which are not normally competent for IL-11 expression. When ligated to the murine c-fos promoter, however, the proIL-1j3 enhancer was inducible in phorbol myristate acetate-stimulated HeLa cells, suggesting the existence of a proIL-1,3 promoter-proximal requirement for tissue specificity.Interleukin 11 (IL-113), a 17-kDa cytokine involved in inflammatory and immunological processes, is produced by activated monocytes/macrophages, fibroblasts, endothelial cells, and other cell types. The IL-1 proteins are translated as larger 31-kDa precursors (proIL-1) which are extracellularly processed into smaller 17-kDa forms (mature IL-1) (4, 20). There are two proIL-1 genes (proIL-lco and proIL-113) coding for distinct proteins which are observed in many different species (7, 18). The two proIL-1 genes are located on human chromosome 2 (11, 30, 48) and show a high conservation of exon/intron structure (7). IL-1 has a variety of biological activities on a wide range of tissues (see reference 13 for a review). For example, IL-1 induces the production of inflammatory mediators, proteolytic enzymes, and other cytokines that are involved in the joint destruction and inflammation of rheumatoid arthritis (29). IL-1 also modifies connective tissue and bone metabolism through the induction and type switch of collagen and the induction of bone resorption (21).The proIL-113 gene is normally not transcribed in competent cells until activated by stimuli such as lipopolysaccharide (LPS) or phorbol 12-myristate acetate (PMA) or by 17-kDa IL-11 protein (9,13,14 with LPS, IL-1P mRNA is rapidly and transiently transcribed in the absence of protein synthesis (15), suggesting the activation of preexisting transcription factors. Our previous studies revealed the importance of promoter sequences immediat...

In these studies, we have identified DNA sequences and specific protein interactions necessary for transcriptional regulation of the human prointerleukin 1 beta (proIL-1 beta) gene. A cell-type-independent lipopolysaccharide (LPS)-responsive enhancer element located between -3757 and -2729 bp upstream from the transcription start site (cap site) consisted of at least six discrete subregions which were essential to the maximal induction by LPS in transfected monocytes. The enhancer also appeared to mediate phorbol myristate acetate induction in monocytes and IL-1 responsiveness in fibroblasts. Deletion and base substitution mutations along with DNA binding studies demonstrated that the enhancer contained a minimum of three functional protein binding sequences, two of which appeared to be important for gene induction. One of the essential proteins which bound to the enhancer was similar or identical to members of the C/EBP family of transcription factors required for both IL-1- and LPS-specific induction of the IL-6 gene (i.e., the NF-IL6 proteins). When ligated to the proIL-1 beta cap site-proximal region (located between -131 to +12), both the proIL-1 beta and the simian virus 40 enhancer elements functioned more efficiently in monocytes than in HeLa cells, which are not normally competent for IL-1 beta expression. When ligated to the murine c-fos promoter, however, the proIL-1 beta enhancer was inducible in phorbol myristate acetate-stimulated HeLa cells, suggesting the existence of a proIL-1 beta promoter-proximal requirement for tissue specificity.