Figure 1.

The dynamic expression of CD38 in CD8⁺ T cells

(A) Representative FACS plots showing CD38 expression in WT mice indicated lymphocytes. B cells with high CD38 as a positive control.

(B and C) Purified WT CD8⁺ T cells were primed by αCD3/CD28 for 24 h, then the protein expression and mRNA transcription levels of CD38 were analyzed via flow cytometry or qPCR, respectively.

(D) Left: the representative histogram of CD38 expression in indicated cells. Right: quantified the dynamic change of CD38 expression of OT-1 cells during OVA peptide activation. The ΔMFI (mean fluorescence intensity) of CD38 was calculated from the difference values between WT and CD38 knockout cells. Data are shown as Mean ± SD (n = 3), Student’s t test, ∗∗∗∗: p < 0.0001; ∗: p < 0.05; ns: not significant.

(E) Left: activated WT or Cd38^−/− OT-1 cells were stimulated with OVA peptide continuously, hypoxia or 2 mM glucose for 4 days. The representative FACS plots of CD38 expression were shown. Right: The ΔMFI was analyzed by flow cytometry and summarized. Data are shown as Mean ± SD (n = 3), Student’s t test, ∗∗∗∗: p < 0.0001; ∗∗∗: p < 0.001; ns: not significant.

(F) Left: representative histogram of CD38 expression in the spleen or B16-F10 tumor-infiltrated CD8⁺ T cells. Right: Statistical analysis of CD38 MFI in indicated cells. Data are shown as Mean ± SD (n = 5), Student’s t test, ∗∗∗: p < 0.001.

(G) Left: CD8⁺ TILs were divided into PD-1⁻TIM-3⁺ T_PRO and PD-1⁺TIM-3⁺ T_EXH in contour plots. Middle: representative FACS plots of CD38 expression in T_PRO or T_EXH cells. Right: the levels of CD38 in these two subsets were compared. Data are shown as Mean ± SD (n = 5), Student’s t test, ∗∗: p < 0.01.