Immune reactivity in congenic mice after allogeneic or isogeneic transfusion

Pretransplant donor-specific blood transfusion has a beneficial effect on subsequent skin graft survival in B10 congenic mice when donor and recipient differ at both the K and I regions of the H-2 complex, but has no effect on graft survival in donor-recipient combinations differing at the K region alone. Immune reactivity was studied in B10.A recipients after a single allogeneic transfusion from B10 donors differing either at both K and I regions or at K alone, or after a transfusion of isogeneic B10.A blood. Spleen cells were assayed for the ability to respond in mixed lymphocyte culture (MLC) and cell mediated lymphocytotoxicity (CML) assays against blood donor and third-party at 2, 9, 16, and 30 days after transfusion. MLC and CML responses were nonspecifically suppressed in recipients transfused with allogeneic blood from K or K and I region disparate donors. The responses of mice receiving K region disparate blood were partially recovered by 9 days posttransfusion and had returned to normal 16 days posttransfusion. Responses of mice receiving K and I region disparate blood remained suppressed 30 days post transfusion. Isogeneic transfusion induced a suppression of the MLC response. Two days posttransfusion, the MLC response was suppressed to a variety of stimulators representing disparity at K alone; K and I; or K, I, and D. The response to K region disparate stimulators had recovered 9 days after isogeneic transfusion, but the response to K and I or K, I, and D region disparate stimulators remained suppressed 30 days after transfusion. The suppression observed after allogeneic or isogeneic transfusion was not due to a shift in the day of peak response in the transfused mice. Kinetic studies showed that the day of peak MLC and CML responses in the transfused mice corresponded to that of normal controls, but the level of response was significantly lower in the transfused mice.