Fig 1: Identification and characterization of different MDSC subtypes in blood from patients with LDH. (A) Frequency of G-MDSCs and M-MDSCs were 0.24 and 2.39%, respectively, in a healthy donor. Gating strategy for MDSCs: For immature MDSCs and G-MDSCs, the acquired cells were first gated on the non-expression of Lin and HLA-DR. Within this population, the fraction of cells expressing both CD33 and SSC was determined. The expression of CD15 was further explored in this fraction. For M-MDSCs, SSC vs. CD14 was first gated to isolate the monocytes cell populations, and then HLA-DR vs. CD14 was plotted for M-MDSCs. (B) Frequency of G-MDSCs and M-MDSCs were 0.87 and 2.61%, respectively, in a patient with stage IV LDH. MDSC, myeloid-derived suppressor cells; LDH, lumbar disc herniation; G-MDSC, granulocyte MDSCs.