Figure 1.

Functional replacement of mouse CTLA-4 with the human CTLA-4 gene in vivo. (a and b) Flow cytometric analysis of intracellular Foxp3 and CTLA-4 in freshly isolated LN CD4⁺ T cells from WT and HuTg mice, labeled with aMUCTLA-4 (a) and aHuCTLA-4 (b). (c) Absolute CD4⁺Foxp3⁺, CD4⁺Foxp3⁻, and CD8⁺ T cell counts from age-matched WT (empty circles) and HuTg mice (filled circles; 8–10-mo-old mice; n = 8–9 per group). (d) Frequency of Ki67-expressing CD4⁺Foxp3⁺, CD4⁺Foxp3⁻, and CD8⁺ T cells in LN of WT (empty circles) and HuTg mice (filled circles). (e) Absolute cell counts for B cell, NK cell, and dendritic cell populations in LN of WT (empty circles) and HuTg mice (filled circles). Data represent three independent experiments. Horizontal bars in c–e represent mean values.