Fig. 4.

CD14⁺ cells were isolated from normal human PBMC by magnetic bead isolation and were cocultured with human PC cell line Panc-1 for 72 h. a Downregulation of HLA-DR expression after tumor exposure; flow cytometry was performed on CD14⁺ cells (from blood) after 72 h of coculture with tumor cells. Representative plots show that approximately 83.5 % CD14⁺ cells had high HLA-DR expression when these cells are incubated in complete medium (CM). After tumor exposure, these cells downregulate HLA-DR expression and 71.4 % CD14⁺ cells have low HLA-DR expression. b Analysis of quantitative RT-PCR results for gene expression of arginase-1 from CD14⁺ cells cocultured with and without tumor. Normalized fold change is depicted. c Representative flow cytometry histogram from T cell suppression assay depicts stimulated, CFSE-labeled CD8⁺ T cells cocultured with tumor-conditioned or unconditioned CD14⁺ cells for 72 h. d Representative flow cytometry plot shows differential expression of HLA-DR on CD14⁺ cells isolated from the blood and human tumor specimens. Bar graphs depict mean division index ± SEM with asterisk denotes p < 0.05 by Mann–Whitney in all panels