| Abstract: | Human peripheral blood leukocytes (PBL) were incubated in Cyclosporine, washed, and then tested for their effect in two- and three-party in vitro cultures. In two-party mixed leukocyte reactions (MLRs), CsA pretreatment (70 ng/ml) of either responder or stimulator PBL produced a potent suppression in [3H]-thymidine uptake by responder PBL (greater than 100% specific inhibition). The ability of CsA-pretreated PBL to suppress the MLR was dependent on the concentration of CsA in which the PBL were incubated. CsA was more effective at suppressing the MLR when pretreated stimulator PBL were added, then when added directly to culture. In three-party cultures, CsA pretreatment of one stimulator population (50 ng/ml) resulted in cytotoxic T lymphocytes that effectively lysed target cells from the untreated population but not targets from the CsA-pretreated population. These results indicate that CsA-pretreated cells can be used to suppress an allogeneic response in a relatively antigen-specific manner, and may have implications for clinical transplantation. |
