Fig. 6

Lactate upregulated CCR8 level and led to Th17/Treg imbalance. (A) The levels of CCR8 in CD4 + CD25 + Treg cells and IL-17 A in CD4 + T cells within intracranial implanted tumor. CD4 + T cells isolated from human PBMCs were treated with lactic acid, sodium lactate, or co-cultured with 51 or 66 A GSCs, the expressions of CCR8 protein in CD4 + T cells (B), CCR8 mRNA expressions (C), H3K18la enrichment on CCR8 promotor (D), and the levels of IL-17 A and IL-4 in the supernatants (E) were measured. (F) CD4 + T cells were transfected with pGL3-CCR8 promotor plasmid for 24 h, then treated with PBS, lactic acid, sodium lactate or co-cultured with 51 or 66 A GSCs, the luciferase activities were measured by dual-luciferase reporter system. (G) The expressions of Ccl1 and Ccl8 mRNA in implanted tumor. (H) The expressions of CCL1 and CCL18 mRNA in THP-1 cells in vitro. *P < 0.05, **P < 0.01