Figure 2. BETi treatment elicits CD8+ T cell-mediated effects.

A-D) Data were obtained from D4M3.A tumors from mice after four days from the treatment start with control or PLX51107 chow. Tumors were similar sizes. Data are displayed as the mean (showing individual mice) percent of total cells +/− SD. A) CD8+ T cells cells in tumors. B) Cytokine production (IFNγ, IL-2 and TNFα) from CD8+ T cells in tumors. C) CD44 and Ki67 positivity of CD8 T cells from non-treated and PLX51107-treated tumors. D) The CD8:Treg ratio in tumors. Significance was assessed by unpaired t-test, *p<0.05. E-G) Mice were depleted of CD8a+ cells, as described in the Materials and Methods. Mice were given either control or PLX51107 laced chow when tumors reached ~50 mm³. E) Representative FACS plots showing the depletion of CD8+ cells in the blood on day 19 after beginning the CD8 depletion. F) Tumor growth in control or CD8 depleted mice, represented as change of volume (mm³) over time, shown from the start of control (anti-CD8a alone, n=3, isotype IgG2a alone, n=3) or PLX51107 diet (PLX51107 + anti-CD8a, n=8; PLX51107 + isotype IgG2a, n=8). Significance was assessed as described in Materials and Methods, ****p>0.0001. G) Tumor survival curves of isotype IgG2a or CD8-depleted D4M3.A tumor-bearing mice treated with control or PLX51107 laced chow, ending when tumors were >450 mm³. Dots indicate when animals were censored due to euthanizing when tumors were <450 mm³. Significance was assessed by a logrank test, ****p<0.0001.