Fig. 3: PROCR promotes IL6 secretion leading to inhibition of anti-tumour immunity.

Proportion of Th1 cells (A) and IFNγ MFI of CD8⁺ T cells (B) in human NPC specimens after coculture with indicated culture medium (CM). C Multiplex cytokine array showing cytokine production in CM of PROCR-knockout (sgPROCR) and parental (sgGFP) HONE1 cells. D ELISA for IL-6 and IL-8 in the supernatant of sgGFP and sgPROCR HONE1 cell. E Proportion of Th1 cells and IFNγ MFI of CD8⁺ T cells in human NPC specimens after coculture with CM from sgPROCR and sgGFP HONE1 cells, with or without anti-IL-6 mAb. F Proportion of Th1 cells and IFNγ MFI of CD8⁺ T cells in human NPC specimens after coculture with CM from sgPROCR and sgGFP HONE1 cells, with or without IL8 knockdown. G Proportion of Th1 cells and IFNγ MFI of CD8⁺ T cells in human NPC specimens after coculture with HONE1 sgPROCR CM + IgG, PROCR-rescue (sgPROCR + PROCR-OE) CM + IgG, or PROCR-rescue CM + anti-IL-6R antibody. H Quantitative polymerase chain reaction (qPCR) analysis of IL6 expression in parental sgGFP, sgPROCR, and PROCR-rescue HONE1 cells. I Proportion of Th1 cells and IFNγ MFI of CD8⁺ T cells in human NPC specimens after coculture with HONE1 PROCR-knockout (sgPROCR + siSCR) CM, PROCR-rescue (sgPROCR + PROCR-OE + siSCR) CM, or PROCR-rescue with IL6 knockdown (sgPROCR + PROCR-OE + siIL6) CM. J–L HONE1^PROCR-Tet-On cells were inoculated into huHSC-NCG mice (5 mice per group). 15 days after inoculation, mice were treated with irradiation, irradiation + Dox, or irradiation + Dox + anti-IL6R antibody. Tumour growth curves were monitored, and tumour volumes and weights were compared at the indicated time points. n = 3 independent experiments (A–I). One of three experiments is shown (C). Data are shown as mean ± SD (A, B, D–I) or mean ± SEM (K, L). P values were calculated using two-tailed unpaired t test (D), one-way ANOVA (E–I, L) or two-way ANOVA (A, B, K). Source data are provided as a Source Data file.