Non-viral neuronal gene delivery mediated by the H-C fragment of tetanus toxin

Many inherited neurological diseases and cancers could potentially benefit from efficient targeted gene delivery to neurons of the central nervous sys tem. The nontoxic fragment C (H-C) of tetanus toxin retains the specific ne rve cell binding and transport properties of tetanus holotoxin. The H-C fra gment has previously been used to promote the uptake of attached proteins s uch as horseradish peroxidase, beta-galactosidase and superoxide dismutase into neuronal cells in vitro and in vivo. We report the use of purified rec ombinant H-C fragment produced in yeast and covalently bound to polylysine [poly(K)] to enable binding of DNA. We demonstrate that when used to transf ect cells, this construct results in nonviral gene delivery and marker gene expression in vitro in N18 RE 105 cells (a neuroblastoma x glioma mouse/ra t hybrid cell line) and F98 (a glioma cell line). Transfection was dependen t on H-C and was neuronal cell type specific. H-C may prove a useful target ing ligand for future neuronal gene therapy.