FIG 5.

CD137 is expressed on splenic CD4⁺ and CD8⁺ T cells, NK cells, and NKT cells in CHIKV-infected mice at 2 dpi. Four-week-old WT C57BL/6 mice were inoculated with 10³ FFU of CHIKV-LR at day 0. At 2 dpi, spleens were harvested and processed for flow cytometry. Flow cytometry dot plots show CD137 expression levels on CD4⁺ and CD8⁺ T cells, CD3-NK1.1⁺ NK cells, CD19⁺ B cells, MHC-II⁺ CD11c⁺ DCs, and CD3⁺ NK1.1⁺ NKT cells. Data are representative of two experiments. The numbers within the flow cytometry plots refer to the percentage of cells in the gated (boxed) areas.