Fig. 4. Pentanoate-treatment enhances the anti-tumor activity of murine CAR T cells.

a Experimental design for the analysis of SCFA-treated ROR1-specific murine CD8⁺ CAR T cells (CAR_ROR1). b The surface expression of CD25 on CAR T cells was measured by flow cytometry analysis after three days of stimulation with butyrate or pentanoate (n = 3 independent experiments). c, d The production of TNF-α and IFN-γ from CAR T cells was measured by ELISA (c) and flow cytometry analysis (d) after three days of stimulation with butyrate or pentanoate. Three similar experiments were performed. e–g Following the pretreatment with pentanoate for three days, ROR1-specific CAR T cells were transferred i.p. into mice bearing 5-days old PancROR1 tumors. Tumor volume (e) and tumor mass (f) were analyzed on day 14 post tumor inoculation (n = 6 mice/group combined from two independent experiments). The percentage and total cell number of transferred TNF-α⁺ and IFN-γ⁺ CAR T cells in the tumor tissue at day 14 after tumor inoculation are shown in (g). For all experiments, 0.75 mM butyrate and 2.5 mM pentanoate were used, respectively. Multiple group comparison in (e) was performed by a linear-mixed effects model with Tukey correction. In b–d and f, g, the two-tailed unpaired Student’s t-test was applied. Source data are provided as a Source data file.