Figure 2.

Sunitinib attenuates the M2-like phenotype in mouse MDSC and suppressive function in CD33⁺CD14⁺CD16⁺ nonclassical monocytes. Human PBMC or sorted human CD33⁺CD14⁺CD16⁺ nonclassical monocytes were left untreated (CT) or treated with sunitinib (SU, 250 nmol/L) for 48 hours followed by staining with indicated antibodies and isotype controls. A, total PBMCs were gated on CD33⁺ cells, and the dot plots of cell populations (left) and the statistical analyses of the percentages of CD33⁺CD14⁺CD16⁺ population (right) were presented. B, flow-cytometric histogram of Annexin V in total PBMC untreated (CT, black) or treated with sunitinib (SU, gray; left). Mean fluorescent intensity of CD206⁺ in Annexin V⁺CD33⁺CD14⁺CD16⁺ cells was shown in the right panel. C, flow-cytometric histograms (left) and mean fluorescent intensity (right) of pSTAT3⁺, CD206⁺, arginase⁺ (M2-like), and iNOS⁺ (M1-like) in sorted human CD33⁺CD14⁺CD16⁺ nonclassical monocytes. (*, P < 0.05, when compared with control group). D, human CD33⁺CD14⁺CD16⁻ classical and CD33⁺CD14⁺CD16⁺ nonclassical monocytic populations were sorted from PBMC of patients before and after sunitinib treatment. Suppressive activity of CD33⁺CD14⁺CD16⁻ and CD33⁺CD14⁺CD16⁺ populations in PBMC was assessed as described in Materials and Methods. (*, P < 0.05; **, P < 0.01, when compared with CD33⁺CD14⁺CD16⁻ group before sunitinib treatment at indicated ratio.)