In vitro targeting and specific transfection of human neuroblastoma cells by chCE7 antibody-mediated gene transfer.

We developed a new vector for gene targeting of neuroblastoma (NB) cells, based on the utilization of a monoclonal antibody (chCE7) covalently linked to polylysine (PL). In the presence of chloroquine, chCE7–PL–DNA complexes transfected NB cells as efficiently as DOTAP, transfectam, TF-X50 or lipofectamine. This was demonstrated by transfection of the luciferase or β-galactosidase reporter genes in three different NB cell lines. This transfection was specific, since it was inhibited in the presence of competing unconjugated chCE7 antibody (Ab), and was not observed in cell lines negative for the CE7 antigen. We tested the potential biological activity of a plasmid coding for γ-interferon (γIFN) transfected with chCE7–PL. HLA ABC expression on NB cells was induced after transfection with pCMV-γIFN at a higher level than after incubation with 1000 IU/ml of purified γIFN. Moreover, these HLA ABC-positive NB cells were able to activate autologous cytotoxic T lymphocytes in vitro. Thus chCE7–PL is able to target a plasmid to NB cells and to allow the expression of the transfected gene in a biologically active form. [ABSTRACT FROM AUTHOR]