Conjugate-based targeting of recombinant adeno-associated virus type 2 vectors by using avidin-linked ligands

J Virol. 2002 Dec;76(24):12900-7. doi: 10.1128/jvi.76.24.12900-12907.2002.

Abstract

The development of targeted vectors, capable of tissue-specific transduction, remains one of the important aspects of vector modification for gene therapy applications. Recombinant adeno-associated virus type 2 (rAAV-2)-based vectors are nonpathogenic, have relatively low immunogenicity, and are capable of long-term transgene expression. AAV-2 vectors bind primarily to heparan sulfate proteoglycan (HSPG), a receptor that is present in many tissues and cell types. Because of the widespread expression of HSPG on many tissues, targeted transduction in vivo appears to be limited with AAV-2 vectors. Thus, development of strategies to achieve transductional targeting will have a profound benefit in the future application of these vectors. We report here a novel conjugate-based targeting method to enhance tissue-specific transduction of AAV-2-based vectors. The present report utilized a high-affinity biotin-avidin interaction as a molecular bridge to cross-link purified targeting ligands, produced genetically as fusion proteins to core-streptavidin, in a prokaryotic expression system. Conjugation of the bispecific targeting protein to the vector was achieved by biotinylating purified rAAV-2 without abolishing the capsid structure, internalization, and subsequent transgene expression. The tropism-modified vectors, targeted via epidermal growth factor receptor (EGFR) or fibroblast growth factor 1alpha receptor (FGFR1alpha), resulted in a significant increase in transduction efficiency of EGFR-positive SKOV3.ip1 cells and FGFR1alpha-positive M07e cells, respectively. Further optimization of this method of targeting should enhance the potential of AAV-2 vectors in ex vivo and in vivo gene therapy and may form the basis for developing targeting methods for other AAV serotype capsids.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Biotinylation
  • Cell Line
  • Dependovirus / classification
  • Dependovirus / genetics*
  • ErbB Receptors / metabolism*
  • Genetic Therapy
  • Genetic Vectors / genetics*
  • Heparan Sulfate Proteoglycans / metabolism
  • Humans
  • Ligands
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Receptor, Fibroblast Growth Factor, Type 1
  • Receptors, Fibroblast Growth Factor / metabolism*
  • Recombination, Genetic*
  • Streptavidin / metabolism*
  • Transduction, Genetic

Substances

  • Heparan Sulfate Proteoglycans
  • Ligands
  • Receptors, Fibroblast Growth Factor
  • Streptavidin
  • ErbB Receptors
  • FGFR1 protein, human
  • Receptor Protein-Tyrosine Kinases
  • Receptor, Fibroblast Growth Factor, Type 1