Activation of DCs, NK cells, and T cells in Peyer patches after vaccination. Mice were killed 1 day after vaccination. Lymphocytes isolated from Peyer patches were analyzed by flow cytometry. (A) Contour plots of CD80 and CD86 expression on DCs (CD11c⁺I-A/I-E⁺). (B) Contour plots of CD69 and NKG2D expression by NK cells (CD3^-DX5⁺). (C) Contour plots of CD69 and NKG2D expression by CD8⁺ T cells (CD3⁺CD8⁺). Vectors used for vaccination are shown at the top of panel A. Experiments were repeated 3 times with similar results.