Fig. 5

Endocrine therapy increases tumour immune cell infiltrate in an immune competent ER+ breast cancer model. a 129/SvEv wild-type female mice received daily treatment of 1 mg/kg letrozole for 25 days, and tumour volume was measured daily. b Immunohistochemistry (IHC) CD3+ staining cell counts from mammary tumours of vehicle and letrozole-treated mice. Cell counts are shown as average number of CD3+ cells in 3–7 fields at 40X magnification. c–e Representative images (40X) of low, medium and high levels CD3+ staining in stromal areas of mammary tumours. f–h FACS analysis of CD3+ (f), CD4+ (g) and CD19+ (h) from tumours of vehicle and letrozole-treated mice. Representative flow cytometry plots are shown in (i). Data are shown as percent total CD45+ lymphocytes/tumour sample. Error bars represent the mean and SEM. P-values were calculated using unpaired t-tests