EXPRESSION OF THE HUMAN DYSTROPHIN GENE IN MDC MOUSE MUSCLE AFTER TRANSFER WITH LIPOSOMES OR SYNTHETIC OLIGOPEPTIDE COMPLEX VECTORS

The number of dysrophin-positive fibers appearing in the femoral quadr iceps muscle of mdx mice after injection of the full-length human dyst rophin cDNA within the pHSADy plasmid was examined by means of immunoh ystochemical techniques. Transfection was carried out using lipofectam ine (LFA), or synthetic oligopeptide complexes that provided the conde nsation of plasmid DNA (K8) and its release from endosomes (JTS1), The LFA + pHSADy at a dose of 10 mu g DNA did not affect the number of dy strophyn-positive fibers at the site of injection (0.6-0.8%), whereas it caused a statistically significant increase in the number of these fibers in the same muscle of the contralateral leg (up to 2.3%). Injec tion of the SO + pHSADy complex resulted in the occurrence of dysrophi n-positive muscle fibers characterized by a heterogeneous content and the distribution of dystrophin. The greatest number of dystrophin-posi tive fibers (about 16%) was observed under a ratio of pHSADy to K8 of 1 : 3 or 1 : 4. The observed maximal number of dystrophin-positive fib ers after a single injection of SO + pHSADy was 3.8%, and it was 17.7% after three injections. These values were statistically significantly higher compared to intact mice (0.6%), the injection of pure plasmid (2.2%), or the intramuscular injection of sucrose (from 0.7 lo 1.3%). A relatively high level of transfection (about 5%) was observed after an intracardiac injection of a large dose of the pHSADy (70 mu g DNA). The perspectives of the targeted delivery of the dystrophin gene into muscles under conditions of parenteral administration are discussed.