Figure 2.

Arkadia is required for iTreg, but not Th17, cell differentiation in vivo. (A) Analysis of CD4⁺ TCRβ⁺ T lymphocytes from LILP of control littermates and Arkadia conditional KO mice under SPF conditions. Left: Representative flow cytometry plots. Right: cell proportions (percentages) and numbers of indicated subpopulations. Data are from one of three independent experiments. n = 13 in the three experiments. (B) Analysis of CD4⁺ TCRβ⁺ T lymphocytes from LILP of control littermates and Arkadia mutant mice colonized with H. helicobacter. Data are representative of two independent experiments (n = 10). Statistical analyses in A and B were performed with unpaired t test. Black circle, control littermates; red triangle, Arkadia conditional KO mice (A and B). (C) Top: Experimental scheme for mixed bone marrow chimera experiment (see Materials and methods). Bottom: Relative ratios of iTreg, Th17, and Th1 lymphocytes in reconstituted mice (designated control/WT and Ark KO/WT). Relative ratios of cell number were normalized to the ratios of donor B cells in peripheral blood. Control/WT (black circle) and Ark KO/WT (red triangle): control or Arkadia mutant cell frequency or number divided by that of WT cells. Data are from one experiment with total 13 mice for two experimental groups. Ratios of cotransferred cells in each animal were calculated individually and combined for analysis with unpaired t test. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. Error bars represent SD.