The cells involved in cell-mediated and transplantation immunity in the normal outbred rabbit. XI. The accelerated response in the one-way MLR of rabbit WBC from skin allograft recipients.

The relationship between allograft rejection and the response in the one-way mixed leucocyte reaction (MLR) of the WBC of allograft recipients was investigated. The responses of the WBC were assessed prior to skin allografting and subsequent to rejection of the allograft. The optimal MLR response of the WBC from the allografted rabbit stimulated with cells from the allograft donor occurred on days 3 to 4 of culture and by day 6 the MLR response was down to control levels. This accelerated response by the allograft-sensitized cells was specific to stimulator cells from the allograft donor as stimulator cells from a third party rabbit induced a normal MLR response by these cells, that is, an optimal response on days 5 to 7 of culture. No evidence of cytotoxic cells was obtained in cultures of cells from allograft-sensitized rabbits. The implications of these results are discussed.