Liver fibrosis results from an imbalance between synthesis and degradation of extracellular matrix components due to a variety of deseases such as virus hepatitis, alcoholic abuse or metabolic dysfunction. The cytokine TGF-ß plays an important role in so far it interferes during hepatic injury with the transcriptional regulation of genes which are responsible for the production and degradation of matrix proteins. A simplified model to investigate liver fibrosis in vitro is the spontaneous activation of cultured hepatic stellate cells (HSC) on a plastic surface to myofibroblasts (MFB) which synthesize the components of the connective tissue. This process of transdifferentiation plays the key role in developing liver fibrosis. In order to prevent proceeding liver fibrogenesis it may be useful to interact with the gene expression of HSC and MFB. The use of adenoviral-mediated gene transfer proved that heterologic genes could be introduced into these cells. A protein cassette is inserted into an E1 – region-deleted adenoviral type 5 genome which now expresses recombinant, replication-deficient adenoviruses. Enhanced green fluorescent protein (EGFP) was used as a reporter construct under the transcriptional control of the human cytomegalovirus promotor (CMV). Both cell types could completely be infected in cell culture by this adenoviral construct. The morphological integrity of adenovirus was shown by electronic microscopy. In order to use this gene transfer system in vitro against liver fibrosis the reporter gene GFP was replaced by a protein with antifibrotic potential, a soluble TGF-ß type II receptor which is fusioned with the Fc-region of human immunogobuline IgG. The CMV-promotor was retained. The expression of this receptor shall interrupt the signal cascade of TGF-ß, thus inhibiting more fibrotic effects by TGF-ß. The existence of this chimeric fusion protein was assessed by Northern Blot, Western Blot and immunoprecipitation, the biological activity was confirmed by proliferation assay
