LIPOSOME-MEDIATED GENE-TRANSFER INTO ESTABLISHED CNS CELL-LINES, PRIMARY GLIAL-CELLS, AND IN-VIVO

Sufficient gene transfer into CNS-derived cells is the most crucial st ep to develop strategies for gene therapy. In this study liposome-medi ated gene transfer using a beta-galactosidase (beta-GAL) reporter gene was performed in vitro (C6 glioma cells, NT2 neuronal precursor cells , 3T3 fibroblasts, primary glial cells) and in vivo, Using Trypan blue exclusion staining, optimal lipid concentration was observed in the r ange of 10-12 mu g/mL. Under optimal conditions (80,000 cells/16 mm we ll, incubation overnight, lipid/DNA ratio = 1:18) a high transfection rate was achieved (<9% for C6 cells; <1% for NT2 cells), In primary cu ltures of glial cells a fair amount of positive stained cells (glial c ell) was found, but the transfection efficiency was lower (<0.1%). A ' 'boost-lipofection'' markedly increased (twice) lipofection efficiency in C6 cells, Expression of beta-GAL reached a maximum after 3-5 days, When the liposome-DNA complexes were injected/infused directly into t he brains of adult rats, several weakly stained cells could be observe d in the brain region adjacent to the injection site. It is concluded that liposome-mediated gene transfer is an efficient method for gene t ransfer into CNS cells in vitro, but the transfection efficiency into the rat brain in vivo is far too low and therefore not applicable, (C) 1998 Elsevier Science Inc.