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 temperaturesensitive simian virus 40 large T antigen. The resultant cells divide indefinitely at 34°C, but differentiate at 38°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. © 1992 John Wiley & Sons, Inc.