Figure 3. Aurora kinase A inhibition ex vivo induces apoptosis in HPV-positive tumor-induced MDSCs but not CD8 T cells. (A–B) Splenocytes isolated from mEER tumor-bearing mice were treated ex vivo with vehicle or alisertib (300 nM) for 6 hours, and apoptotic cells (annexin V⁺) within the MDSC (A) and CD8 T cell (B) fractions were identified by flow cytometry. (C) MDSCs and CD8 T cells (C) from the mEER tumors were purified and treated ex vivo with vehicle or with alisertib (300 nmol/L) for 6 hours. Protein extracts were analyzed for apoptosis and survival pathway proteins using an antibody array. The significance of differences was determined using an unpaired, two-tailed Student’s t-test. ns (not significant), *p≤0.01, **p≤0.004, ***p≤0.0001. Cyto-C, cytochrome C; HPV, human papillomavirus; MDSCs, myeloid-derived suppressor cells.