Fig. 4: SAM and MTA treatment promotes dysfunction of human CD8+ T cells in vitro.

a The viabilities of activated CD8+ T cells after exposing to indicated concentrations of SAM or MTA for 72 h. Data are presented as mean ± S.D.; n = 4 independent biological experiments. P value was calculated using a one-way ANOVA test with Tukey’s multiple comparisons test for subgroup comparison. b Representative histogram of CFSE-labeled human peripheral CD8+ T cells underwent indicated treatments and indicated time points. The effects of different treatments on cell proliferation are compared using the proliferation index estimated by FlowJo (lower panel). Data are presented as mean ± S.D. and p value between mock and each treatment was calculated using two-sided independent t test. (n = 3 independent biological experiments). c Representative expressions of CD44 and CD28 of human CD8+ T cells underwent SAM, MTA or mock control treatment for 3, 7, and 4 days. Expressions of CD44 and CD28 on CD3+ CD4− CD8+ CD45+ cell were analyzed and the average fraction of cells positive for CD44 and CD28 at various time points are shown at the bottom panel. Bar, mean; error bars, S.D.; n = 3 independent biological experiments. Statistical significance was assessed by two-sided independent t test. d SAM/MTA treatment attenuated interferon-gamma secretion after PMA/ionomycin stimulation. Representative interferon-gamma expression of cells CD3+ CD4− CD8+ CD45+ T underwent indicated treatments were shown. The average fraction of cells with increasing interferon-gamma expression is shown below. Bar, mean; error bars, S.D.; n = 3 independent biological experiments. P value between mock and each treatment was calculated using two-sided independent t test. e Representative expressions of PD1, TIM3, and CD28 of human CD8+ T cells underwent SAM, MTA, or mock control treatment for 3, 7, and 14 days. The average fraction of CD3+ CD4− CD8+ CD45+ T cells positive for CD28, PD1, and TIM3 at various time points are shown at the bottom panel. Data are presented as mean ± S.D. and p value between mock and each treatment was calculated using two-sided independent t test. (n = 3 independent biological experiments). f, g SAM/MTA treatments promote the expressions of TOX and Tbet in CD8+ T cells. Representative histograms and median fluorescence intensity (MFI) of TOX and Tbet in CD3+ CD8+ TOX+ T cells f and CD3+ CD8+ Tbet+ T cells g were shown. Bar, mean; error bars, S.D.; n = 3 independent biological experiments. P value was calculated using a one-way ANOVA test with Tukey’s multiple comparisons tests. Source data are provided as a Source Data file.