Fig. 5

Co-treatment with fulvestrant increases the ratio of CD8+: FOXP3+ cells and markers of T cell activity in the TC11 TME. A Schematic of treatment timeline. TC11 cells were transplanted to the caudal mammary fat pad as in Fig. 1. Fulvestrant (Fulv)/ oil control treatments were initiated 3 weeks after transplantation, and/or a single dose of RT (8 Gy) was administered 1 week after initiation of fulvestrant treatments. TC11 tumors were collected at day 10 after RT for immunohistochemistry, flow cytometry and qPCR analyses. B Intratumoral CD8+ T cells at day 10 after RT were immunostained and quantified as described in the Materials and Methods. i. Quantification of intratumoral CD8+ infiltrate (mean ± SEM, n = 5). Differences among treatments were determined by one way ANOVA, followed by Tukey post tests. *, p < 0.05. ii. Intratumoral CD8+ cells shown by immunohistochemical staining, representative sections. Original magnifications, × 200; scale bar = 50 µm. C Ratio of CD8+: FOXP3+ cells in the tumor infiltrate. Proportions of CD8+ and FOXP3+ cells in CD45+ immune cells were determined by flow cytometry (mean ± SEM, n = 4). Differences among treatments were determined by one way ANOVA, followed by Tukey post tests. *, p < 0.05. D Relative levels of transcripts for genes reflecting T cell activity (mean ± SEM, n = 7–10). Differences among treatments were determined by one way ANOVA, followed by Tukey post tests. *, p < 0.05; **, p < 0.01