Retroviral vectors displaying functional antibody fragments

We have made retrovirus particles displaying a functional antibody fragment. We fused the gene encoding an antibody fragment directed against a hapten with that encoding the viral envelope protein (Pr80^env) of the ecotroplc Moloney murine leukemia virus. The fusion gene was co-expressed in ecotroplc retrovlral packaging cells with a retrovlral plasmld carrying the neomycln phosphotransferase gene (neo), and retrovlral particles with specific hapten binding activities were recovered. Furthermore the hapten-binding particles were able to transfer the neo gene and the antibody-envelope fusion gene to mouse fibroblasts. In principle, the display of antibody fragments on the surface of recomblnant retrovlral particles could be used to target virus to cells for gene delivery, or to retain the virus in target tissues.