Figure 5.

High amount of antigen and IL-12 is required for CD8+ T cells long-term antigen-recall response. Naïve OT-I/PL cells stimulated with 16.7% or 100% ratio of BOK/MECII cells with or without IL-12 were harvested at 72 h and adoptively transferred (2×10⁶ cells) into naïve B6 recipients. The recipients were challenged with 5 μg OVA in IFA on Day 66, and secondary CD8+ T cell responses were measured 4 days after the challenge. (A) The absolute number of adoptively transferred antigen conditioned OT-I T cells on Day 66 (left panel). The absolute number of OT-I cells, the absolute numbers of IFN-γ-secreting OT-I T cells, and the in vivo antigen-specific cytolysis after challenge in recipients received antigen-conditioned OT-I cells (right panel). (B) The absolute number of adoptively transferred antigen plus IL-12 conditioned OT-I T cells on Day 66 (left panel). The absolute number of OT-I cells, the absolute numbers of IFN-γ-secreting OT-I T cells, and the in vivo antigen-specific cytolysis after challenge in recipients received antigen plus IL-12-conditioned OT-I cells (right panel). Representative data of two independent experiments are shown. ND, Not determined. *, P < 0.05; **, P < 0.01.