Hyperacute rejection of the transplanted mouse heart

Mouse hearts transplanted heterotopically to MHC-disparate recipients can be hyperacutely rejected (HAR) after a single or 3 sequential donor type skin grafts, or a single intradermal injection of lymphoid cells. In the combinations tested, not all hearts are HAR; most of them are rejected in accelerated fashion. Our results with transplanted rat hearts are similar, even in a genetic combination for which HAR of all hearts has been reported. However, in rats, HAR tends to occur more rapidly and to be associated with more-intense vascular changes. Transfer of serum from mice or rats sensitized by 3 sequential skin grafts likewise resulted in occasional hyperacute but never accelerated rejection. Transfer of lymph node cells from mice sensitized with a single skin graft always resulted in accelerated but never in hyperacute rejection; transfer of cells after 3 sequential skin grafts caused neither accelerated nor hyperacute rejection.