Fig. 5: Macropinocytosis delivers free AA to T cells necessary for sustained activation of mTORC1.
From: Macropinocytosis drives T cell growth by sustaining the activation of mTORC1
a, b Splenocytes were stimulated with CD3/28 mAb for 12 h followed by incubation with DQ Red BSA for 4 h at the indicated temperatures in the presence or absence of NH4Cl (a) or for 8 h at 37 °C in the presence or absence of EIPA or NH4Cl (b). Flow cytometry histogram plots show DQ Red BSA fluorescence (a) or phospho-S6 levels (b) in CD4+ T cells. Plots are representative of three repeat experiments (see Supplementary Fig. 6b, d). c Splenocytes were stimulated with CD3/28 mAb in complete medium (RPMI plus FCS) for 12 h, washed and recultured in the indicated media for 2 h in the presence or absence of EIPA. Representative flow cytometry histograms show phospho-S6 levels in CD4+ T cells. All panels are from the same experiment. The mid-blue-dashed line indicates all AA in the absence of EIPA. d Mean±1 SEM of the fold increase in mTORC1 activation in CD4+ T cells at 14 h relative to the 0 AA control in the absence of inhibitors (n = 8 and 7 independent experiments for 20 AA and LQRS, respectively, in the absence of inhibitors; n = 4 for 20 AA and n = 3 independent experiments for LQRS and 0 AA in the presence of inhibitors). **P < 0.01 by Student’s 1-sample 2-sided t-test. Source data are provided as Source Data file.
