Acute destruction of rat skin grafts by alloantisera

Rat skin transplanted to mice or to allogeneic rats can be acutely and severely damaged by injecting the graft recipients with alloimmune serum of appropriate specificity. This susceptibility of rat skin to alloantisera has been obscured in previous studies by the fact that the extent of serum-mediated damage that occurs is decisively influenced by the interval of time between placement of the grafts and the injection of antiserum. Grafts are resistant to damage during the 1st week after transplantation; they rapidly develop sensitivity during the 2nd week, reaching a peak at 14 to 16 days; and during the next few weeks the sensitivity is lost. Grafts surviving beyond 35 to 40 days become totally resistant to antisera. LBNF1 GRAFTS Are more resistant than Le or BN grafts to BN anti-Le serum or Le anti-BN serum, respectively. However, combinations of the two sera can act synergistically to destroy LBN skin that has been grafted to immunosuppressed mice. This form of serum-mediated tissue damage is thought not to play a significant role in skin graft rejection in the usual circumstances of transplantation since cell mediated immunity is well developed before the acquisition by the grafts of sensitivity to humoral agents. Furthermore, antisera from animals that have rejected a single graft have little or no destructive potential, and hyperimmune animals reject skin very shortly after grafting, often before the grafts have become vascularized and hence before they are sensitive to antiserum.