Female c57bl 6

Female Swiss Webster mice (6-8 weeks of age) were purchased from the Jackson Laboratory (Bar Harbor, ME), and female C57BL/6 were purchased from Taconic Farms (Germantown, NY). C.129S4(B6)-Il12b^tm1Lky/J (IL-12p40-YFP) mice were obtained from the Jackson Laboratory and maintained as a breeding colony at Cornell University College of Veterinary Medicine. Infections were initiated in 8-12 week old mice by oral inoculation of 30 cysts of the T. gondii type II ME49 strain or 40 cysts of the type II Prugniaud-RFP OVA (Pru-RFP) strain. Cysts were generated by an initial intraperitoneal injection of 100 tachyzoites into Swiss Webster mice to establish chronic infection. Cysts were subsequently harvested from chronically infected Swiss Webster mice by homogenizing whole brain in PBS.

Female C57BL/6 and BALB/c mice were purchased from Taconic Farms and were used at an age of 12 weeks. PD-1 KO C57BL/6 mice were provided by L. Chen (Yale University, New Haven, Connecticut, USA) with the permission of T. Honjo (Kyoto University, Kyoto, Japan). The Bcl2l11^−/− (Bim KO) mice on a C57BL/6 background were purchased from Jackson Laboratory. Mice were maintained under pathogen-free conditions and used at 8 to 12 weeks of age. PD-L1 WT or KO tumor cells were isolated from WT breast cancer NeuT mice provided by L. Pease (Mayo Clinic, Rochester, Minnesota, USA) or from PD-L1 KO NeuT mice (Mayo Clinic, Rochester, Minnesota, USA). B16 or B16-OVA murine melanoma cells were provided by R. Vile (Mayo Clinic, Rochester, Minnesota, USA). All cell lines were free of Mycoplasma contamination (Mycoplasma Detection kit; Roche Diagnostics). Tumor cells were cultured in RPMI 1640 medium (Cellgro) with 10% FBS (Life Technologies), 1 U/ml penicillin, 1 μg/ml streptomycin, and 20 mM HEPES buffer (all from Mediatech).

Female Swiss Webster mice (6–8 weeks of age) were purchased from the Jackson Laboratory (Bar Harbor, ME), and female C57BL/6 were purchased from Taconic Farms (Germantown, NY). C57BL/6-Tg (TcraTcrb)425Cbn/J (OT-II) mice were obtained from the Jackson Laboratory and maintained as a breeding colony at Cornell University College of Veterinary Medicine. The β-catenin Ex3^fl/fl mice were kindly provided by M. M. Taketo (Kyoto University) and were maintained as breeding colonies crossed to CD11c-cre expressing mice at the Transgenic Mouse Core Facility at the Cornell University College of Veterinary Medicine. Cre⁺ offspring (Ex3^DC−/− mice) were identified by PCR amplification of the Cre gene from genomic DNA isolated from tail snips. Infections were initiated in 8–12 week old mice. T. gondii infections were performed by intraperitoneal inoculation of 25 cysts of the type II ME49 strain. Cysts were isolated from chronically infected Swiss Webster mice by homogenization of whole brain in sterile PBS. Alternatively, mice were inoculated with 2×10⁵ pfu of recombinant vaccinia virus expressing MHCI-restricted HSV gB_498-505 (VACV-gB) by intraperitoneal injection (17 (link)). VACV-gB was maintained in 143B cells for the generation of viral stocks.