Yosef S Haviv1, Koichi Takayama2, Peter A Nagi1, Albert Tousson3, William Cook4, Minghui Wang1, John T Lam1,4, Seiji Naito5, Xiaosheng Lei1, Delicia E Carey6, David T Curiel1. 1. Division of Human Gene Therapy, Departments of Medicine, Pathology and Surgery, University of Alabama at Birmingham, Birmingham, AL, USA. 2. Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. 3. Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL, USA. 4. Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA. 5. Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. 6. Department of Medical Statistics, University of Alabama at Birmingham, Birmingham, AL, USA.
Abstract
BACKGROUND: Systemic adenoviral (Ad) gene therapy for renal disorders is largely hampered by the unique architecture of the kidney. Consequently, currently available Ad vectors are of only limited therapeutic utility in the context of glomerular and fibroproliferative renal diseases. METHODS: The Ad vectors studied in the context of blocking renal fibrosis were AdTbeta-ExR and AdCATbeta-TR. AdTbeta-ExR encodes a chimeric soluble molecule comprising the entire ectodomain of the human type II TGF-beta receptor, genetically fused to the Fc fragment of the human IgG1 (sTbetaRII), while AdCATbeta-TR encodes only the dominant-negative truncated ectodomain of the human type II TGF-beta receptor. The biologic activity of the type II TGF-beta receptor was evaluated in vitro by its ability to inhibit cellular proliferation and in vivo in a unilateral ureter obstruction fibrosis model. Renal targeting with sTbetaRII was evaluated immunohistochemically after intramuscular (IM) delivery of AdTbeta-ExR. The renal antifibrotic effect of the Ad vectors was evaluated in a lupus murine model with both light and electron microscopy and urinalysis. RESULTS: sTbetaRII was detected in the glomeruli after remote IM injection of AdTbeta-ExR, but not the control AdCATbeta-TR, indicating renal deposition of the heterologous soluble fusion protein after its expression in the muscle and secretion into the circulation. AdTbeta-ExR, but not AdCATbeta-TR, could transiently inhibit mesangial expansion, glomerular hypercellularity, proteinuria and cortical interstitial fibrosis in a murine lupus model. However, the autoimmune renal disease eventually surpassed the antifibrotic effect. CONCLUSIONS: These results indicate the superiority of a soluble type II TGF-beta receptor over a dominant-negative, non-soluble type II TGF-beta receptor in the context of blocking renal fibrosis in murine models. Copyright 2003 John Wiley & Sons, Ltd.
BACKGROUND: Systemic adenoviral (Ad) gene therapy for renal disorders is largely hampered by the unique architecture of the kidney. Consequently, currently available Ad vectors are of only limited therapeutic utility in the context of glomerular and fibroproliferative renal diseases. METHODS: The Ad vectors studied in the context of blocking renal fibrosis were AdTbeta-ExR and AdCATbeta-TR. AdTbeta-ExR encodes a chimeric soluble molecule comprising the entire ectodomain of the human type II TGF-beta receptor, genetically fused to the Fc fragment of the human IgG1 (sTbetaRII), while AdCATbeta-TR encodes only the dominant-negative truncated ectodomain of the human type II TGF-beta receptor. The biologic activity of the type II TGF-beta receptor was evaluated in vitro by its ability to inhibit cellular proliferation and in vivo in a unilateral ureter obstruction fibrosis model. Renal targeting with sTbetaRII was evaluated immunohistochemically after intramuscular (IM) delivery of AdTbeta-ExR. The renal antifibrotic effect of the Ad vectors was evaluated in a lupus murine model with both light and electron microscopy and urinalysis. RESULTS: sTbetaRII was detected in the glomeruli after remote IM injection of AdTbeta-ExR, but not the control AdCATbeta-TR, indicating renal deposition of the heterologous soluble fusion protein after its expression in the muscle and secretion into the circulation. AdTbeta-ExR, but not AdCATbeta-TR, could transiently inhibit mesangial expansion, glomerular hypercellularity, proteinuria and cortical interstitial fibrosis in a murine lupus model. However, the autoimmune renal disease eventually surpassed the antifibrotic effect. CONCLUSIONS: These results indicate the superiority of a soluble type II TGF-beta receptor over a dominant-negative, non-soluble type II TGF-beta receptor in the context of blocking renal fibrosis in murine models. Copyright 2003 John Wiley & Sons, Ltd.