PBMCs but not CBMCs produced IFN-γ in response to ESAT-6. (A) Comparison of IFN-γ production by PBMCs and CBMCs in response to ESAT-6 measured by ELISA (n = 6). (B) The frequency of IFN-γ–producing cells were assessed by ELISPOT (n = 6). The cultures were set up in triplicate. Each symbol represents one datum from one donor. ***P < .001. Horizontal bars represent mean values. (C) The expression of CD45RA and CD45RO on γδ T cells in PBMCs and CBMCs were shown. Data are representative of 5 experiments yielding similar results. (D) γδ T cells from PBMCs and CBMCs were assessed by FACS for the expression of CD45RA, CD45RO, CD27, CD62L, and CCR7 in 5 independent experiments (mean ± SD); **P < .05 compared with PBMCs.