REGULATION OF INTERLEUKIN (IL)-1-BETA GENE-TRANSCRIPTION INDUCED BY IL-1-BETA IN RHEUMATOID SYNOVIAL FIBROBLAST-LIKE CELLS, E11, TRANSFORMED WITH SIMIAN-VIRUS-40 LARGE T-ANTIGEN

Objective. To investigate the process involved in the production of an d responsiveness to interleukin 1 beta IL-1 beta in synovial fibroblas t-like cells, we analyzed the enhancer region of pro-IL-la gene in a c ell clone, E11, established from a patient with rheumatoid arthritis ( RA). Methods. A cell clone, E11, was derived from rheumatoid synovial fibroblast-like cells transformed with simian virus 40 large T antigen expression vector by electroporation. Responsiveness of E11 to IL-1 b eta was analyzed by [H-3] thymidine incorporation and Northern blottin g, IL-1 beta responsive elements on pro-IL-la gene were analyzed by ch loramphenicol acetyltransferase analysis. Results. E11 resembled synov ial fibroblasts based on morphological characteristics and phenotypic analysis, It also demonstrated marked enhancement of proliferation and rapid induction of IL-1 beta mRNA expression by IL-1 beta. We also id entified IL-1 beta responsive elements on the pro-IL-1 beta gene at a position between -3134 and -3092 that contains the AP-1 binding site a nd between -2782 and -2729, which includes both AP-1 and nuclear facto r-kappa B (NF-kappa B) binding sites, Conclusion. AP-1 and NF-kappa B binding elements were required for transcriptional regulation of the I L-1 beta gene in the autocrine growth system of RA synovial cells.