Fig. 5

Expression of HLA-DR, CD86 and PD-L1 were increased, while expression of CD163 was decreased on CD14⁺ monocytes,concomitant with downregulation of CD16, in the co-cultures of tumor cells and PBMC or purified monocytes in the presence of cetuximab. Total PBMC or purified monocytes from HNSCC patients with new active diseases (n = 9) were co-cultured with PCI15B or JHU029 for 3 days with 10 μg/mL hIgG1 or cetuximab before analysis of surface markers on CD14⁺ monocytes by flow cytometry. Summary graphs showing fold changes (MFI normalized to each isotype) of HLA-DR, CD86, PD-L1 and CD163 on CD14⁺ monocytes from PCI15B+ PBMC (a), JHU029+ PBMC (b), PCI15B+ purified monocytes (c) and JHU029+ purified monocytes (d) co-cultures supplied with 10 μg/mL hIgG1 or cetuximab. Surface expression of CD16 of gated CD14⁺ monocytes from the co-cultures of tumor cells and PBMC/monocytes indicated above or cultures of PBMC/monocytes alone without tumor cells was analyzed by flow cytometry. Summary graphs of fold change of CD16 on CD14⁺ monocytes from the co-cultures of tumor cells and PBMC/monocytes (e) and cultures of PBMC/monocytes in the absence of EGFR⁺ tumor cells (f) are shown. The graphs present the mean ± SEM from advanced disease HNSCC patients (n = 9). Statistical significance was determined by Wilcoxon matched-pair signed rank tests. **p < 0.01