Fig. 1: mGluR4 suppresses the maturation and function of DCs.

A The CD11b⁺ cells were purified from spleens of WT mice, and BMDCs and BMDMs were induced by GM-CSF (20 ng/ml) or L929 cellular supernatant, respectively (n = 3 biological replicates). The RNA levels of mGluR4 were analyzed by qPCR analysis. B BMDCs pretreated with fresh media (FM) or Hepa1-6BL tumor cell conditioned media (TCM) for 24 h (n = 3 biological replicates). The expression of Grm4 was determined by qPCR. C Expression level of CD40, CD80, and CD86 in WT or Grm4^-/- BMDCs cultured with FM or Hepa1-6BL TCM for 24 h. D Geometric mean fluorescence intensity (gMFI) of CD40, CD80, and CD86 in WT or Grm4^-/- BMDCs from (C) (n = 4 biological replicates). E Diagram of CD8⁺ T cell and BMDC coculture assay. F–I WT or Grm4^-/- BMDCs were cultured in FM or Hepa1-6BL TCM for 24 h, then pulsed with 1 ng/ml OVA peptide for 2 h before being co-cultured with CTV-labeled OT1 CD8⁺ T cells in a 1:10 ratio. T-cell proliferation, cytokine production, and cytotoxicity against tumor cells were measured 2 days later. F Representative histogram plots and statistical analysis of the proliferation of CD8⁺ T cells (The clusters of 1, 2, and 3 represent the different times of division of CD8⁺ T cells, respectively, and 0 represents the initial CD8⁺ T cells) (n = 4 biological replicates). G The level of IFNγ in the cell culture supernatant from (F) was measured by ELISA kit (n = 3 biological replicates). H Expression levels of granzyme B and IFNγ in CD8⁺ T cells (n = 4 biological replicates). I The apoptosis of Hepa1-6BL (n = 5 biological replicates). Data were presented as mean ± SEM. Statistical significance was determined by unpaired t-test two-tailed (B, D, F, G, H, I). All biological experiments were repeated at least three times and yielded consistent results. Source data are provided as a Source Data file.