Figure 7. Peritoneal and splenic granulocytic MDSCs from tumor-bearing mice suppress T cell proliferation independently of NADPH oxidase.

Ly6G-enriched PECs and splenocytes from MOSEC-bearing WT and p47^phox−/− mice (day 90) were co-cultured with splenocytes from non-tumor-bearing WT mice (E∶T ratio: 1∶1). A) Ly6G-enriched PECs completely suppressed anti-CD3/B7.1-stimulated CD4⁺ and CD8⁺ T cell proliferation. PECs from 3 mice per genotype were evaluated. B) In Ly6G-enriched splenocytes, the majority of cells had a granulocytic morphology (arrows), and 86% of CD11b⁺ cells expressed granulocytic MDSC markers (Ly6G⁺Ly6C^low). C) Ly6G-enriched splenocytes from WT and p47^phox−/− mice modestly suppressed anti-CD3/B7.1-stimulated CD4⁺ and CD8⁺ T cell proliferation. N = 3 mice per genotype were used in this experiment, and results are representative of 3 experiments. Comparison between genotypes: p = NS.