1. Supplemental Figure 1 A B Supplemental Figure 1. F ‑ IgG and IL-12 mediated NK cell lysis is dependent on the folate receptor availability and does not correlate with FcR genotype. (A) The lytic activity of cytokine-activated NK cells was assessed in a standard 4-hr chromium release assay in the presence of C-IgG or F-IgG coated KB tumor cells. Tumor cell folate receptors were blocked with the addition of increasing concentrations of folate such that low, intermediate and low FR availability was achieved. Purified NK cells were incubated overnight with medium alone or medium supplemented with IL-12 (0.5 ng/mL) at various E:T ratios (x ‑ axis). Results are representative of data derived from n > 3 donors/patients. (B) Eight normal NK cell donors were genotyped and assayed for ADCC at various E:T ratios against the KB tumor cell line in medium supplemented with IL-12 (0.5 mg/mL).

2. Supplementary Figure 2 Supplemental Figure 2. MDSC inhibit NK cell lytic activity and IFN-γ production. The lytic activity of NK cells was assessed in a standard 4-hr chromium release assay in the presence of F-IgG coated KB tumor cells. MDSCs were added to purified NK cells at a ratio of 0.5:1 and co-cultured with tumor cells at various NK:tumor E:T ratios (x ‑ axis) (left panel). MDSC were also added to purified NK cells (in the presence or absence of IL-12 at 10 ng/mL) and co-cultured with KB tumor cells (with or without F-IgG) for 24 hours. Culture supernatants were the harvested and analyzed IFN-γ by ELISA (right panel). PBMC:NK co ‑ culture conditions served as a control in all experiments.

3. Supplementary Figure 3 Supplemental Figure 3. CIgG-FITC and FIgG-FITC treated mouse tissues exhibit normal histological features. Tissues (spleen, liver, lung, heart and brain) were harvested from mice treated with CIgG-FITC or FIgG-FITC and H&E stained. Image analysis indicated normal histology (10X magnification images) in all groups. As expected, splenic tissue contained leukemic cells in all tumor bearing mice.