FIG 2.

ELISPOT assay of IFN-γ production by splenocytes from mice that were naive or chronically infected with T. gondii. Mouse splenocytes were collected 30 days after T. gondii infection and stimulated with ESA as an antigen-specific positive control (1 µg/ml), ConA as a nonspecific positive control (1 µg/ml), Sumo as a negative control (1 µg/ml), or MIC1, M2AP, MIC4, MIC6, or MIC10 (1 µg/ml), or MIC3 (0.5 µg/ml). Cells were stimulated for 24 h from either BALB/c (A) or C57BL/6 (B) mice. ELISPOT analysis was performed on 6 naive and 12 chronically infected BALB/c mice and 7 naive and 11 chronically infected C57BL/6 mice. Ordinary one-way ANOVA with Sidak’s multiple-comparison test was used to compare ELISPOT results. *, P ≤ 0.05; ***, P ≤ 0.001; ****, P ≤ 0.0001. ns, nonsignificant.