Fig. 6: Metformin treatment expands CD8⁺CXCR3⁺ T_M cell population in humans.

a Strategy of analyzing PBMCs from metformin-treated healthy individuals. b t-SNE map of human peripheral CD8⁺ T cells with manually cluster gating for T_E, T_M, and T_N cells. c Normalized expression intensities of indicated markers were calculated and overlaid on the t-SNE plot, characterizing all cluster of human CD8⁺ T cells. d Manual gating identified differential expression of CD127 and CXCR3, distinguishing two CD8⁺ T_M subpopulations, T_M1 and T_M2. e Frequency of CD8⁺CD127⁺CXCR3⁺ T_M cells before and after metformin treatment. n = 8 subjects, analysis by Wilcoxon matched-pairs signed rank test. f Overlay plot showing expression of BCL2 in CD8⁺CD127⁺CXCR3^- and CD8⁺CD127⁺CXCR3⁺ T_M cells. BCL2 expression in CD8⁺ T_N cells is also indicated. Data shown from one representative donor. g Flow cytometric analysis of frequency of peripheral CD8⁺CXCR3⁺ T_M cells in T2D patients receiving either metformin or other diabetic monotherapy, n = 18 other monotherapy group, n = 42 metformin group. Box-and-whisker plot show the median, 5 and 95 percentiles. Analysis by two-tailed t test with Welch’s correction.