Figure 1.
Histopathology changes in mouse lungs after instillation with HE staining (×200).
The scale on the graph above was 50 µm; date was day3, day7, day28. Lung sections were stained with H&E. The degree of inflammation was assessed by the histological analysis of six random fields per sample (with n = 5 mice per group).
Figure 2.
Depletion of Tregs increased the accumulation of inflammation cells in the lung of experimental silicosis mice.
The total cells (A), macrophages (B) lymphocytes (C) and neutrophils (D), in BALF(day 3) were counted by using Giemsa staining. Results (n = 5) are shown as mean±SEM (one-way analysis of variance followed by pair-wise comparison with the Student-Newman-Keuls test. *, as compare with the saline control group, P<0.05; Δ, as compared with the silica group, P<0.05).
Table 1.
Cell infiltration and alveolar change of the mice lungs in each group at day 3, 7, 28 and 56.
Figure 3.
Depletion of Tregs decreased Th17 response in silica induced lung fibrosis.
The RORγ-t (A) and IL-17A (B) mRNA were assayed by realtime RT-PCR by using −ΔΔCt method. Results (n = 5) are shown as mean±SEM (one-way analysis of variance followed by pair-wise comparison with the Student-Newman-Keuls test. *, as compare with the saline control group, P<0.05; Δ, as compared with the silica group, P<0.05; + compared with 3day of the same group, P<0.05; #, as compared with 7day of the same group, P<0.05).
Figure 4.
The localization of CD4+IL-17A+ cells in lung tissue examined by immunofluorescence (×600).
The CD4+(red) cells, IL-17A+(green) cells and CD4+IL-17A+(yellow) cells were colocalized in the lung tissue sections by confocal immunofluorescence microscope, analyzed with the leica confocal software package. Results from one representative experiment out of 5 (with n = 5 mice per group) are shown.
Figure 5.
TGF-β1 and IL-10 decreased in the Tregs depletion group and TGF-β1 may contribute to the Th17 cells differentiation.
The IL-10 (A) and TGF-β1 (B) mRNA (day 3) were assayed by realtime RT-PCR by using −ΔΔCt method. Results (n = 5) are shown as mean±SEM (one-way analysis of variance followed by pair-wise comparison with the Student-Newman-Keuls test. *, as compared with the saline control group, P<0.05; Δ, as compared with the silica group, P<0.05).
Figure 6.
The regulatory function of Tregs on Th17 and IL-17A may depend on IL-1β but not IL-6 and IL-23.
The IL-1β (A), IL-6 (B) and IL-23 (C) mRNA were assayed by realtime RT-PCR by using −ΔΔCt method. Results (n = 5) are shown as mean±SEM (one-way analysis of variance followed by pair-wise comparison with the Student-Newman-Keuls test.*, as compared with the saline control group, P<0.05; Δ, as compared with the silica group, P<0.05; +, as compared with 3day of the same group, P<0.05; #, as compared with 7day of the same group, P<0.05).
Figure 7.
Th1 type of cytokines took the advantage over Th2 cytokine in the depletion of Tregs.
Typical Th1 IL-2 (A), IFN-γ (B), IL-12 (C) and Th2 IL-4 (D) cytokines (day 3) were assayed by realtime RT-PCR by using −ΔΔCt method. Results (n = 5) are shown as mean±SEM (one-way analysis of variance followed by pair-wise comparison with the Student-Newman-Keuls test. *, as compared with the saline control group, P<0.05; Δ, as compared with the silica group, P<0.05).