Long term survival of allografted muscle precursor cells following a limited period of treatment with cyclosporin A.

Previous work (Watt et al., 1982) has shown that, in the mouse, skeletal muscle can be transplanted successfully in the form of a suspension of it's mononucleate precursors. Eventual therapeutic application of this technique by the implantation of precursor cells derived from normal muscle into myopathic individuals would require a means of preventing allograft rejection applicable to man. We have therefore investigated the use of the drug cyclosporin A (CyA) as a means of prolonging the survival in mice of allografts of mononucleate muscle cells made into a region of regenerating host muscle. We have administered CyA to the hosts at doses of either 75 or 150 mg/kg body weight/day for 42 days from the day of grafting. By using isoenzyme allotypes as markers of host and donor tissues, we have shown that allografted mononucleate cells become incorporated in host muscle fibres and that the mosaic host/donor muscle fibres so formed survive for as long as we continued the experiment, a maximum of 107 days after grafting, or 65 days after the end of CyA treatment.