CD25highCD278+CD183+CD8+ Treg inhibit B cell proliferation
Purified B cells were first labeled with CFSE and then co-cultured without or with sorted CD25highCD278+CD183+CD8+ Treg in B: CD8Treg ratio of 1:1, 1:1/2 and 1:1/4 and activated with 2ug/ml of anti-CD40 and 2.5ug/ml of CpG and cultured for 5 days, and proliferation was determined by CFSE dilution assay. A representative flow cytometry histogram is shown in Figure 4A and cumulative data from 6 different individuals are shown in Figure4B. CD8 Treg, in a concentration-dependent manner inhibited B cell proliferation at B:CD 8Treg ratio of 1:1 (P< 0.0008), 1:1/2 (P<0.008), and 1:1/4 (P>0.80).