Fig. 3
Expansion of M-MDSC by DEX is mediated via α2-AR. a Expression of α2-AR on CD11b+CD33+HLA-DR− (MDSC), CD11b+CD33+HLA-DR−CD14− (G-MDSC) and CD11b+CD33+HLA-DR−CD14+ (M-MDSC) was analyzed in peripheral blood mononuclear cells (PBMC) of lung cancer patients at time of preoperatoin (T0), 1, 3 and 7 days after surgery (T1, T2 and T3) by flow cytometry (FCM). Representative FCM data of α2-AR on MDSC, G-MDSC and M-MDSC on days 3 after tumor resection are shown. b–d Mean fluorescent intensity (MFI) of α2-AR on b MDSC, c G-MDSC and d M-MDSC was assessed. **P < 0.01 and ***P < 0.001 as compared with T0 in Ctrl group; #P < 0.05 ###P < 0.001 as compared with T0 in DEX group. e–g CD11b+CD33+HLA-DR− cells (3 × 104 cells/well) isolated from lung cancer patients (n = 16) 24 h after surgery were cocultured with dexmedetomidine (DEX) (2.5 ng/mL), yohimbine (YOH, an α2-adrenergic antagonist) (2.5 ng/mL), or dexmedetomidine (2.5 ng/mL) and yohimbine (2.5 ng/mL) (DEX + YOH). Twelve, twenty-four and forty-eight hours after coculture, floating cells were gently collected and numerated using an automated cell counter. The percentage of MDSC, G-MDSC or M-MDSC was analyzed by FCM and the absolute number of these cells was calculated. *P < 0.05, **P < 0.01, ***P < 0.001