Figure 3. Production of sCD25 during the in vitro suppression assay.

Supernatants from triplicate wells were pooled and analyzed for the production of sCD25 by ELISA (n = 7 control subjects). Under conditions of both serum-free and 1.0% serum, the highest levels of sCD25 were detected in the 1∶1 Treg to Teff co-culture condition at the early 48 h time point, but were only significantly higher in media containing 1% serum ((A) and (B)). At the 96 h time point ((C) and (D)), the pattern of sCD25 production more closely resemble the responses observed in the proliferation assay assessed by uptake of ³H-thymidine. (*p<0.05, **p<0.01, and ***p<0.001).