T-cell activation in vivo by FBS DCs. (A) BALB/c mice were treated with 10⁶ syngeneic FBS DCs or PBS on days -14 and -7. Splenocytes were harvested on day 0 and 10⁶ cells were cultured in medium containing 10% FBS or 1.5% NMS for 72 hours and cytokine production was analyzed. Each dot represents an individual mouse. (B) As in panel A, except that cells were cultured in 1.5% NMS medium with the indicated concentrations of BSA and cytokine production was measured. (C) As in panel A, but cells were labeled with CFSE before culture and analyzed by flow cytometry. Cells are gated on live CD4⁺ and CD8⁺ cells. (D) As in panel A, except that cells from FBS DC-treated animals were depleted of the indicated subsets before culture. Figures are representative of 2 to 4 independent experiments.