Figure 1. CD14⁺HLA-DR^–/lo distribution and phenotypes in the blood, LNs, and tumors from HNSCC patients.

(A) Relative abundance of circulating CD14⁺HLA-DR^–/lo MDSC (with respect to CD11b⁺ cells prior to sorting in a given compartment) on HNSCC patients (SCCHN) (n = 20) versus patients with chronic tonsillitis (n = 9; **P < 0.01). The mean CD11b⁺ cells from these 2 patient populations were not statistically different. (B) Relative abundance of CD14⁺HLA-DR^–/lo MDSC from PB (n = 37), DLNs (n = 10), and the primary tumor from HNSCC patients (n = 27; *P < 0.05, **P < 0.01). (C) Representative histograms of MDSC markers on CD14⁺HLA-DR^–/lo cells from PB and tumor with isotype controls as shaded areas. The expression of CD33, CD34, CD14, and CD11b was similar between blood and tumor-infiltrating MDSC. There was a differential expression of CD15 in this population between PB and the primary tumor. (D) Circulating CD14⁺HLA-DR^–/lo cells demonstrated skewing toward higher percentage of the HLA-DR^int population, while the tumor and LNs had a greater percentage of the HLA-DR^– phenotype (central and right panels, respectively). Numbers represent the percentages of cells in the indicated boxes.