VERY EFFICIENT MYOBLAST ALLOTRANSPLANTATION IN MICE UNDER FK506 IMMUNOSUPPRESSION

Transgenic CD1 mice expressing beta-galactosidase were used as myoblas t donors. The myoblasts were injected in normal or mdx muscles previou sly irradiated and injected with notexin. Twenty-eight days after myob last transplantation, the percentage of muscle fibers beta-galactosida se-positive was low in mice not immunosuppressed but was high (80%) in those treated with FK506. In mdx mice, muscle fibers expressing beta- galactosidase were also dystrophin positive. Most of the mice not trea ted with FK506 produced antibodies against the donor myoblasts. These results indicate that FK506 is a very useful immunosuppressive drug fo r myoblast transplantation in mice. Irradiation and notexin injection used in our experiments are, however, not feasible in humans. Other ma nipulations capable of increasing the participation of donor myoblasts to regeneration will therefore have to be identified before new clini cal trials are attempted. (C) 1994 John Wiley & Sons, Inc.