Fig. 2

Epithelial cells interact with T cells through receptor-ligand pairs and activated fibroblasts in vitro. (A) Probability values for all receptor-ligand pairs between Epi1.2 cells and T cells. MIF, MDK, and PARD3 are ligands in Epi1.2 cells, and CD74/CXCR4, NCL, CD74/CD44, and GZMA are receptors in T cells. (B) The role of Epi1.2 cells and T cells in the MIF signaling pathway. Epi1.2 cells are the senders and T cells are the receivers. (C) Levels of Epi1.2 cells and their ligand MIF in clinical samples. The red arrows indicate the positive cells. Scale bar = 50 μm. (D) Levels of T cells and their receptors CD74 and CXCR4 in clinical samples. Scale bar = 20 μm. (E) Cell viability of epithelial cells after stimulation with arecoline (0, 20, 40, 60, and 80 µg/mL) for 0, 24, or 48 h, n = 3. (F) Immunofluorescent validation of the Epi1.2 cell model. Scale bar = 30 μm. (G) Quantification of the fluorescence area in the control and Epi1.2 cell model, n = 3. (H) The concentration of cytokines (IFN-gamma, TNF-α, TGF-β, IL-17, IL-6, and IL-1β) in the cell supernatant of different groups was determined using ELISA, n = 3. (I) Fluorescence images of α-SMA after treatment with different cell supernatants. HGF: human gingival fibroblasts. Scale bar = 20 μm. (J) Quantification of fluorescence area in (I), n = 3. (K) The mRNA expression of ACTA2 (α-SMA) after treatment with different cell supernatants, n = 3. (L) Diagrammatic representation of epithelial-T cell interactions influencing OSF progression. Epi1.2 cells interact with T cells through the ligand-receptor crosstalk of MIF-(CD74/CXCR4), activating T cells and promoting fibrosis. The results are presented as the mean ± S.D. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001