Gene transfer facilitated by a cellular targeting molecule, reovirus protein sigma1.

To facilitate eventual genetic vaccination of mucosal tissues, a receptor-mediated gene transfer system was devised using the reovirus adhesin, protein sigma1. Highly efficient uptake and internalization of protein sigma1 polylysine (PL) DNA complexes could be demonstrated by fluorescent microscopy. Successful cellular transfection of rodent and human cell lines was obtained with the recombinant protein sigma1 as a PL-DNA complex, and could be shown to be receptor-specific. Transfection efficiency was dependent upon the ratio of DNA complexed to protein sigma1-PL and chloroquine treatment improved transfection efficiency dramatically. To test its ability to bind a mucosal inductive tissue, recombinant protein sigma1 was specifically bound to the nasal-associated lymphoid tissues (NALT). Thus, recombinant protein sigma1-PL-DNA conjugates can efficiently bind and transfect cells that express the receptor for protein sigma1. Gene Therapy (2000) 7, 61-69.