NR AWRD
AU Zuber,C.; Rey,C.; Knackmuss,S.; Mitteregger,G.; Hallek,M.; Büning,H.; Little,M.; Weiss,S.
TI Recombinant AAV encoding for single chain antibodies directed against the prion protein receptor lrp/lr as a gene therapeutic approach in TSE therapy
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions THE-24
PT Konferenz-Poster
AB
The 37kDa/67kDa laminin receptor (LRP/LR) acts as the cell surface receptor for the cellular prion protein (1) and the infectious prion protein (PrPsc) (2). The necessity of the laminin receptor for prion propagation has been shown by downregulation of LRP/LR using siRNAs and antisense RNAs on scrapie infected neuroblastoma cells (N2a) (3). In addition, a LRP/LR specific polyclonal antibody (W3) was able to abolish PrPsc propagation in scrapie infected neuroblastoma cells (3), demonstrating that the disruption of the LRP-PrP interaction is a relevant strategy to treat prion diseases. Since single chain antibodies provide alternative tools for therapeutic approaches, which are used e.g. in clinical trials for cancer treatment, we developed single chain antibodies directed against LRP/LR. Selection by phage display resulted in two scFvs termed N3 and S18 (4). Both scFvs are able to recognize specifically the denatured form of LRP as well as the native form on the cell surface of N2a cells. Since passive immunotransfer is not sufficient for permanent scFv delivery, we developed recombinant AAV encoding for scFv. We proved expression of the scFvs in the brain of mice after intracerebral AAV injection and treated scrapie infected mice intracerebrally with rAAV expressing scFvs by a stereotactic device. Although spleen analysis revealed a significant reduction of the PrPsc levels, the survival times were not significantly prolonged. In addition, we are improving the single chain antibodies by chain shuffeling to improve the dissociation constant to the antigen, which might result in a more efficient in vivo effects.
(1) Gauczynski et al. (2001) EMBO J. 20, 5863-5875. (2)Gauczynski et al. (2006) J. infect. Dis. In press (3) Leucht et al. (2003) EMBO rep 4, 290-295. (4) Rey et al., submitted.
AD C. Zuber, C. Rey, S. Weiss: Genzentrum - Institut für Biochemie der LMU München, Feodor-Lynen-Str. 25, D-81377 Munich, Germany; S. Knackmuss, M. Little: Affimed Therapeutics AG-Technologiepark- Im Neuheimer Feld 582, D-69120 Heidelberg, Germany; G. Mitteregger: Zentrum für Neuropathologie und Prionforschung der LMU München, Feodor-Lynen-Str. 23, D-81377 Munich, Germany; M. Hallek,, H. Büning: Universität zu Köln, Klinik I für Innere Medizin, Joseph-Stelzmann-Str. 9, D-50924 Köln, Germany. E-mail: weiss@lmb.uni-muenchen.de
SP englisch
PO Italien