MPSSS promoted differentiation of MDSCs.

<p>(A) FACS-sorted splenic MDSCs from McgR32 tumor-bearing mice with or without MPSSS stimulation were viewed with bright-field illumination, (original magnification ×200) and (B) after Wright’s staining for nuclei (original magnification ×200). (C) Electrical impedance measured using a real-time cell electronic sensing (RT-CES) system. (D) All adherent splenocytes from McgR32 tumor-bearing mice were cultured with or without MPSSS for 72 hours and the expression of MHC I, MHC II, F4/80, CD11c or CD86 on MDSCs were analyzed by FACS. (E) Immunofluorescent staining of F4/80 on MPSSS-treated MDSCs (original magnification ×100). (F) Purified MDSCs were stimulated with MPSSS for 4 hours, and the expression of CXCL9, IL-6, or TGF-β mRNA was determined by RT-PCR. Results were given relative to β-actin mRNA and are presented as means ± SD of triplicate samples from one representative experiment. Data is analyzed with Student's <i>t-</i>tests. *<i>P</i><0.05, **<i>P</i><0.01.