Z Gastroenterol 2013; 51 - P_1_16
DOI: 10.1055/s-0032-1331916

Adenoviral-mediated specific targeting of hepatic stellate cells as a selective therapeutic approach in liver fibrosis

B Genz 1, J Reetz 2, C Meier 2, BS Kowtharapu 2, A Stoll 2, F Timm 1, B Vollmar 1, B Pützer 2, K Abshagen 1, O Herchenröder 2
  • 1University of Rostock, Institute for Experimental Surgery, Rostock, Germany
  • 2University of Rostock, Department of Vectorology and Experimental Gene Therapy, Rostock, Germany

*equal contribution

The activation of hepatic stellate cells (HSCs) is a central pathological process in the development of liver fibrosis. Thus, activated HSCs are attractive targets for antifibrotic therapies. We established an adenoviral based gene transfer system for the selective transduction of HSCs by linking a HSC-specific peptide to the virus envelope. The NGFp peptide displays a part of the nerve growth factor (NGF) binding site to p75 neurotrophin receptor (p75NTR), which is in the liver solely expressed on HSCs.

Two different methods for the construction of virus particles selectively infecting HSCs were realized. Both the covalent coupling of the peptide to the fiber by polyethylene glycol (PEG) and a non-covalent linked bispecific anti fiber single chain antibody (S11) were used to modify the natural adenovirus (Ad) tropism of the native adenoviral vector (Ad.GFP; including GFP reporter gene).

In vitro studies with primary mouse hepatocytes and in vivo infection experiments with Balb/C mice showed an equivalent inhibition of the Ad tropism to coxsackie-adenovirus receptor (CAR) by PEG- as well as S11-linkage to Ads (Ad.GFP). Additionally, NGFp-coupled Ads transduced selectively primary cultured HSCs and HSCs after intravenous infection of mice livers. The latter could be verified by visualizing the colocalization of GFP fluorescence and HSC-associated vitamin A autofluorescence using intravital fluorescence microscopy and subsequent immunohistochemical analysis of the of GFP and p75NTR

The use of p75NTR as a target for redirecting adenoviral vectors to HSCs is a new strategy to modulate these cells selectively. The shift of the natural Ad tropism is possible through covalent and non-covalent linking of the NGFp to the virus envelope. This offers new possibilities to introduce therapeutic genes into HSC without any undesirable side effects on hepatocytes or other non-parenchymal liver cells.