Fig. 7. CD8⁺ T cells expanded under high lactate condition show potent tumor growth inhibition in vivo.

a Treatment regimen of T cell receptor engineered T cell therapy (TCR-T). OT-I splenocytes were cultured ex vivo for 4 days with or without 40 mM sodium lactate in the culture medium. After purification with negative selection magnetic beads, CD8⁺ T cells were transferred to MC38-OVA tumor bearing mice. Average tumor size is above 100 mm³ at the time of cell transfer. b The growth curves of MC38-OVA tumor model were significantly inhibited after transfer of TCR-T (5 × 10⁵ or 2 × 10⁶) pretreated with sodium lactate (n = 5). c Analysis of tumor-infiltrating T cells after adoptive TCR-T cell transfer. Seven days after the cell transfer, tumor-infiltrating lymphocytes were analyzed by flow cytometry. d–f Flow cytometry plot and quantification of transferred (CD45.2⁺) and endogenous (CD45.1⁺) OVA-tetramer⁺ CD8⁺ T cells show lactate pretreatment significantly increased the number of transferred CD8⁺ T cells (CD45.2⁺) but not endogenous CD8⁺ T cells (CD45.1⁺) in the MC38-OVA tumors (n = 5). Data are shown as means ± SEM. P-value was determined by one-tail two-way ANOVA with correction using Tukey method (b, c) or one-tail one-way ANOVA with correction using Geisser-Greenhouse method (e, f). Source data are provided in Source Data file.