Characterization of myeloid-derived suppressor cells in tumor-bearing mice.

<p>1×10⁵ TC-1 cells were injected subcutaneously into wild type C57BL/6 mice. 20 days later, splenocytes from naïve (control) or tumor-bearing mice were stained with FITC-conjugated Gr-1 antibody and PE-CD11b antibody. (<b>A</b>) Flow cytometry analysis to demonstrate CD11b and Gr-1 positive cells. (<b>B</b>) Bar graph depicts % of CD11b and Gr-1 positive cells (mean ± SD). Data shown are from one representative experiment of three performed. For the characterization of MDSC-mediated CD8+ T cell suppression, MDSCs were purified by magnetic cell sorting using mouse CD11b MicroBeads. The purity of MDSCs was determined by flow cytometry. Purified MDSCs were used in the T cell activation and proliferation experiment as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103562#s2" target="_blank">Materials and Methods</a>. (<b>C</b>) Bar graph depicting the % of IFN-γ positive cells in CD8 positive splenocytes (mean ± S.D.). (<b>D</b>) Representative flow cytometry histograms showing T-cell proliferation after stimulation with CD3 and CD28 Antibody. (<b>E</b>) Bar graph depicting the % of proliferated cells in CD8 and CFSE positive splenocytes (mean ± S.D.).