Increasing the proliferative capacity of muscular dystrophy myoblasts.

Temperature-sensitive immortalized neural cells may be utilized to produce genetically engineered neural transplants. We have used a similar approach with mdx myoblasts. Control and mdx myoblasts were immortalized with a recombinant retrovirus that effects the expression of a temperature-sensitive simian virus 40 large T antigen. The resultant cells divide indefinitely at 34 degrees C, but differentiate at 38 degrees C, both morphologically and immunocytochemically. Polymerase chain reaction analysis of RNA confirmed the presence of the dystrophin point mutation in the mdx cells and its absence in the control cells. A similar approach may be useful for the proliferation, modification, and reimplantation of autologous cells from patients with degenerative and dystrophic disorders such as Duchenne muscular dystrophy.