Fig. 1: TCR stimulation induces the expression of BCAT1 and SLC7A5 in human CD4⁺ T cells.

a, b The mRNA and protein expression of BCAT1 and BCAT2 in human CD4⁺ T cells from healthy controls (HCs) was analyzed by RT‒qPCR (A; n = 5) and immunoblotting (B; n = 3) at 24 h with or without TCR stimulation. c Public RNA-seq data (GEO No: GSE140244) were analyzed to examine the expression of 42 amino acid transporters at the indicated time points in TCR-stimulated human CD4⁺ memory T cells. Heatmap analysis (left) and fold change in the expression (right) of amino acid transporters at the indicated times after TCR stimulation. d The expression of major BCAA transporters was validated by RT‒qPCR at 24 h poststimulation in human CD4⁺ T cells from HCs (n = 5). e The protein expression of SLC7A5 in human CD4⁺ T cells from HCs was analyzed at 24 h with or without TCR stimulation (n = 3). f Uptake of ³H-leucine by TCR-stimulated human CD4⁺ T cells in the presence of 50 mM BCH and 10 μM JPH203 (n = 5). The graphs show the means ± SEMs. *p < 0.05, **p < 0.01, and ***p < 0.001 according to the Mann‒Whitney U test (a, d, f), two-tailed unpaired t test (b, e), or one-way ANOVA with Tukey’s test (f).