Transcription factors for Th cell polarization in the mice without arthritis at 8 weeks p.i. CD4+ cells were isolated from either LN or spleens of IL-1Ra-deficient mice without the development of arthritis at 8 weeks p.i., and levels of mRNA expression of T-bet (A), GATA-3 (B), and RORγt (C) were comparatively measured with those of uninfected mice as described in Materials and Methods. The results from uninfected mice (white columns) or T. gondii-infected mice (black columns) are normalized with GAPDH mRNA in the same sample. Values represent results from three independent experiments with three mice per group. Statistical differences between groups are shown as follows: *, P was <0.05; and **, P was <0.01.