Fig. 1

TIGIT+CD226+ CD4 T cell frequencies were highly correlated with DM disease activity. a Multi-parameter strategy for assessing the cell surface expression of TIGIT and CD226 on T cells. b Frequency of TIGIT+CD226+ CD4 T cell subset was positively associated with disease activity and closely related to ILD involvement. DM patients with ILD (n = 16), DM patients without ILD (n = 14), and healthy controls (n = 26). Spearman’s correlation analysis was used to test for correlation; two groups were compared using unpaired two-tailed t test. Data are shown as the mean ± SD. c Representative FACS plots showing the percentages of TIGIT+CD226+ T cell/CD4+ T cells in DM patient with ILD and DM patient without ILD. d Representative FACS plots and a scatter plot showing decreased percentages of TIGIT+CD226+ CD4 T cells following treatment with medium dose glucocorticoids and disease-modifying anti-rheumatic drugs (n = 5). Comparison between two groups was carried out using paired two-tailed t test. Data are shown as the mean ± SD. e One-way ANOVA test was used to compare the means of TIGIT+CD226+ CD4 T cells levels between MSAs specific subtypes. p values < 0.05 were considered significant, *p < 0.05, **p < 0.01, ***p < 0.001