Fig. 2.

Strongly activated memory CD8+ T cells are less susceptible to TGF-β-mediated suppression. Stimulations were 24 h with CD3/28, 100 nM SIINFEKL (N4), 100 nM SIIQFEKL (Q4), rIL-12, rIL-15, and rIL-18 in combination, with rIL12 and rIL-15 at 100 ng/mL and rIL-18 at 0.5 ng/mL (“Cyt”), and TGF-β at 20 ng/mL. (A) Representative gating of IFN-γ and GzmB staining in OT-I T_mem at 24 h post stimulation with CD3/28, N4, Q4, or Cyt in the presence or absence of TGF-β. (B) Frequencies of IFN-γ and (C) GzmB of OT-I T cells 24 h post indicated stimulation condition in the presence of titrated TGF-β (N4 conditions are depicted from n = 7 animals, Q4 from n = 5, and Cytokines from n = 6). Each point represents an individual animal with connecting lines across points from the same animal. TGF-β was titrated in twofold dilutions starting with 20 ng/mL and ending with 0.04 ng/mL, in fivefold dilutions starting with 20 ng/mL and ending at 0.032 ng/mL, and in fivefold dilutions starting with 1 ng/mL and ending at 0.0016 ng/mL (for N4 and Cyt). Calculated ½ Max inhibitory capacity values indicated. Data shown are from 4 to 6 independent experiments.