Overexpression of fibrinogen-like protein 2 protects against T cell-induced colitis

Figure 4 Foxp3⁺ Treg are increased and CD3⁺ T cells are decreased in mice that received fgl2^Tg Treg. A: Representative photomicrographs of CD3 and Foxp3 staining of colonic sections. Sham colons were negative for both CD3 and Foxp3. Mice that received Teff and no Treg or fgl2^+/+ Treg had large numbers of CD3⁺ T cells in the lamina propria and epithelium, whereas colons from mice that received fgl2^Tg Treg had only patchy CD3⁺ T cell infiltrates. Original magnification × 100; B: Representative photomicrographs of CD3 and Foxp3 staining of MLN sections. MLN from sham mice had very few CD3⁺ cells. In contrast, large numbers of CD3⁺ T cells were seen in the MLN of the other groups of mice. Treg staining was absent in the MLN of sham mice and very few Foxp3⁺ cells were seen in mice that only received Teff or mice that received fgl2^+/+ Treg, whereas large numbers of Foxp3⁺ cells were seen in mice that received fgl2^Tg Treg. Original magnification × 100; C: Absolute numbers of CD3⁺ cells by morphometry (cells/mm²); D: Absolute numbers of Foxp3⁺ T cells by morphometry (cells/mm²); E: Ratio of Foxp3⁺ to CD3⁺ T cells in each tissue section. Data represent the mean ± SD. Quantification is based on two independent experiments with n ≥ 5 mice per group (^aP < 0.05, ^bP < 0.01, ^eP < 0.001). MLN: Mesenteric lymph nodes; Teff: Effector T cells; Treg: Regulatory T cells.