Fig. 2: TIGIT deficiency promotes Th1 and Th17 cell differentiation in patients with PM.

a, b Naive CD4⁺ T cells isolated from PBMCs from HC or PM patients were stimulated with αCD3/CD28 for 5 d. TIGIT expression in CD4⁺ T cells was measured by flow cytometry. Representative contour plots were shown. Data from four biologically independent replicates. c–i Naive CD4⁺ T cells from patients with PM or HC were transfected with pcDNA3.1-hTIGIT or pcDNA3.1-Vector by electroporation. Cells were then stimulated by αCD3/CD28 for 5 d. c Overexpression of TIGIT in CD4⁺ T cells from HC or PM was confirmed by western blot. The experiment was repeated three times independently with similar results. d, e Overexpression of TIGIT in CD4⁺ T cells from HC or PM was confirmed by flow cytometry. Data from five biologically independent replicates. f, g Naive CD4⁺ T cells were cultured and polarized under Th1 cell conditions for 5 d. IFNγ and T-bet expression in CD4⁺ T cells were measured by flow cytometry. Data from six biologically independent replicates. h, i Naive CD4⁺ T cells were cultured and polarized under Th17 cell conditions for 5 d. The expressions of FoxP3 and IL-17A were measured by flow cytometry, and data from five biologically independent replicates. j, k Naive CD4⁺ T cells were polarized in Th1 condition in the presence of recombinant human CD155-Fc (10 μg/ml) or IgG1 control for 5 d. IFNγ and T-bet expression in CD4⁺ T cells were measured by flow cytometry. Data from five biologically independent replicates. l, m Naive CD4⁺ T cells polarized in Th17 condition in the presence of recombinant human CD155-Fc (10 μg/ml) or IgG1 control for 5 d. IL-17A and FoxP3 expression in CD4⁺ T cells were measured by flow cytometry. Data from five biologically independent replicates. All data are mean ± SEM. Statistics were done by two-way ANOVA followed by adjustments for multiple comparisons.