Figure 4.

Depletion of the gut microbiota results in reduced number of activated CD4⁺ T cells in the mediastinal LNs and reduced T cell heart infiltration. WT mice were treated with ABX and subjected to 4 weeks TAC or Sham, as in Fig 3. Flow cytometry quantification (a) and representative plots (b) of CD4⁺ CD62L^low CD44^high effector T cells in the mediastinal LNs of Sham and TAC with or without ABX treatment. Hearts were digested and analyzed by flow cytometry using the indicated gating strategy (c). T cells (d) and CD11b⁺ cells (e) were quantified. Representative pictures of a CD4 immunostaining (F, arrows) and quantification of CD4⁺ T cells (g) in LV sections in Sham and TAC mice treated with or without ABX. Scale bar: 50 μm. ANOVA test (a, g) or Student t test (d, e) were used; **p < .01; ***p < .001; ns: not significant