E8icre

Six-to eight-week-old C57BL/6, Cd11c^cre, Zbtb46^cre, Cd4^cre, E8i^cre, Lysm^cre, Cx3cr1^cre and Foxp3-ERT2^cre mice were purchased from the Jackson Laboratory. Havcr2^fl/fl mice were generated as described in supplementary materials. TIM-3 conditional knockout mice were generated by crossing to the above cre lines. For knockin/knockout alleles (Lysm^cre) the appropriate controls were used; that is, Havcr2^fl/+ × Lysm^cre+/−, for all other cre lines fl/fl mice were used as controls. For experiments with Foxp3-ERT2^cre mice, mice were orally gavaged with 8 mg tamoxifen 3 days before tumour implantation and every 3 days thereafter for the duration of the experiments. Havcr2^+/+Foxp3-ERT2^cre were used as an additional wild-type control but results were comparable to Havcr2^fl/fl and were therefore not included. Deletion efficiency was determined by flow cytometry (not shown). Animal experiments were done in accordance with the guidelines of the institutional Animal Care and Use Committee (IACUC) at Brigham and Women’s Hospital and Harvard Medical School. All animals were euthanized before reaching humane endpoint, with tumour growth no greater than 2 cm in any one direction or of a total of 400 mm² overall. Mice of both sexes were used throughout the study; sex-matched and age-matched (8–12 weeks) controls were used in individual experiments.

C57BL/6 (WT; Stock number 000664), C57BL/6 Rag2−/− (008449), Tcrb/Tcrd−/− (002122), Ighm−/− (002288), Four Core Genotype (FCG) (27 (link)) (010905) and E8I-Cre (008766) mice were obtained from Jackson Labs. Ar^flox/flox mice were a gift from the laboratory of Dr. Xue Sean Li from Cedars-Sinai and were bred with the E8I-Cre mice to knockout AR within CD8⁺ T cells. FCG model involves manipulation of the Sry gene to create the following four “core” genotypes that can be used to investigate the contribution of sex chromosome complement and gonadal hormones to a given phenotype: XX (“XXF”), XY⁻ (“XYF”), XXSry (“XXM”) and XY⁻Sry (“XYM”) (65 (link)). 5-12 weeks old mice, maintained in a specific pathogen-free environment, were used for experiments. Experimental protocols that involved FCG mice were approved by the Institutional Animal Care and Use Committee (IACUC) at Boston Children’s Hospital. All remaining experiments were conducted under IACUC protocols approved by the Medical University of South Carolina and the Ohio State University.