Figure 4. miR-155^−/− mice display decreased spleen T cell activation during CVB3-induced VM.

miR-155^−/− and WT mice received 1 × 10⁵ PFU of CVB3 i.p. on day 0, and splenocytes were isolated on day 7. (A) The proportion of total CD4⁺ T cells was analyzed by FACS. (B) Activated CD4⁺ and CD8⁺ T cells were determined by surface CD62L^low expression. (C) 5-bromo-2-deoxyuridine (BrdU) was administered (0.8mg in 1ml PBS) 1 day before termination of mice. The proliferation of CD4⁺ T cells was determined by BrdU incorporation assay in vivo. (D) The proportion of CD4⁺CD25⁺Foxp3⁺ Tregs was analyzed by FACS. Experiments were repeated three times in triplicate with 10 mice per group. Bar graph data are presented as mean ± SD; **P < 0.01 and ***P < 0.001 as compared with WT.