Prolonged Urinary Excretion of 51Chromium Label from Cyclosporine-Pretreated Human Fetal Splenocytes following Infusion in the NOD Mouse 1

Abstract Human fetal splenocytes were isolated, labeled with 51chromium, and transfused into NOD male mice for determination of cell survival. One-half of the mice received splenocytes which had been incubated in cyclosporine A (CSA, 20 μg/ml) for 30 min and washed extensively, while controls received splenocytes incubated in diluent alone. After the first transfusion of splenocytes, survival was the same for both CSA-treated and control animals with a t 1/2 of 34 days. A second survival study showed a decrease of t 1/2 in the control animals to 18 days and an increase in the animals receiving CSA treated cells to 53 days (P < 0.01). These in vivo studies confirm in vitro studies documenting that pretreatment of donor cells with CSA is an effective means of modulating the immune response.