[Expression of the human dystrophin gene in mdx mouse skeletal muscles after ballistic transfection].

"Gene-gun" ballistic transfection (BT) was used to deliver genetic constructs pMLVDy and pHSADy containing full-length cDNA of the dystrophin gene to musculus quadriceps remoris and musculus gluteus of mdx mice, which represent a natural model of Duchenne muscular dystrophy. Clusters of dystrophin-positive muscular fibers (DPMF) were immunocytochemically detected in sites exposed to BT. The average number of DPMF was 2% by the 17th day and 3% by the 60th day after BT with pMLVDy, whereas the number of revertant DPMF was 0.2% in control mice (without BT). When pHSADy was used, the average number of DPMF was 3% 20 days after BT. In this case, dystrophin was uniformly spread though the myoplasm in 3% of cells and produced a slight signal in separate regions under the sarcolemma in 10% of muscle fibers. The number of revertant DPMF increased to 0.6% after BT with naked particles and to 2.8% after BT with the marker lacZ gene, in both bombarded and contralateral legs. The number of DPMF in the corresponding muscles of the contralateral leg significantly increased and reached 2.8% by the 60th day after BT with pMLVDy and 6.7% by the 20th day after BT with pHSADy. Human dystrophin gene cDNA was detected in all skeletal muscles, heart, intestine, tongue, and brain by polymerase chain reaction (PCR) three weeks after BT. Immunoblot analysis showed that normal 427-kDa human dystrophin was synthesized in muscles of mdx mice. The results suggest applicability of BT for delivery of dystrophin constructs into muscles.