Figure 1

Schematic of Co-culture and MDSC Suppression Assays for the in vitro generation of tumor-associated myeloid suppressor cells. Induction: Normal donor PBMC are co-cultured with human solid tumor cell lines for one week. MDSC Isolation: CD33⁺ or CD11b⁺ cells are isolated from PBMC-tumor co-cultures by anti-CD33 or anti-CD11b microbead labeling and magnetic column separation. Suppression Assay: Tumor-educated CD33⁺ or CD11b⁺ cells are subsequently co-cultured with fresh, autologous CFSE-labeled T cells at a 1:4 ratio in the presence of T cell stimuli. After 3 days, T cell proliferation is measured as CFSE-dilution using flow cytometry. Suppressive function is evaluated as the ability of CD33⁺ or CD11b⁺ cells to inhibit autologous T cell proliferation.