Figure 4. CD40 is required from maximal accumulation of CD4⁺ ATTs in response to diet-induced obesity.

WT and KO mice were fed ND and HFD, respectively, for 20 wk (n = 5–8 mice/group). ATTs were identified and quantified in eWAT by flow cytometry (see Supplement Fig. 1 for gating strategy). (A) Quantitation of CD3⁺ ATTs. Data are expressed as the percentage of total SVCs and total cells/gram of adipose (eWAT) tissue. (B–C) Quantitation of CD3⁺CD8⁺ ATTs, and CD3⁺CD4⁺ ATTs. (D) Representative flow plots demonstrating T_conv (Foxp3⁻) and T_reg (Foxp3⁺) CD4⁺ ATTs in eWAT from WT and KO mice fed an HFD. Percentage of CD4⁺ ATTs in each gate is indicated. (E) Quantification of T_conv (CD3⁺CD4⁺Foxp3⁻) and T_reg (CD3⁺CD4⁺Foxp3⁺) ATTs. Ratio of T_conv:T_reg ATTs was also determined. (F) Quantification of CD4⁺ T cells and CD8⁺ T cells in spleens from HFD-fed mice. G: Quantification of T_conv and T_reg cells, and ratio of T_conv:T_reg in spleens from HFD-fed mice. Data are means ± sem. *P < 0.05, **P < 0.01, ***P < 0.001. #P < 0.05 vs. ND-fed mice.