Figure S4. Effect of housing temperature and host Sdc1 on T cells within lung metastases. A subset of animals was moved to a housing environment with a thermo-neutral temperature of approximately 31 °C, 2 weeks prior to inoculation and maintained at that temperature throughout the duration of the experiment. The 4T1 mouse mammary carcinoma cells were inoculated into the mammary fat pad as described. Mice were killed after 30 days and sections of lung tissue were labeled with antibodies to CD4 and CD8. CD4+ and CD8+ intratumoral and normal lung lymphocytes were counted as described in “Methods”. (A, B) Photomicrographs of adjacent sections of small lung metastasis (M) next to vessel (V) labeled with antibodies to CD4 (A) and CD8 (B) (original magnification × 400). (C, D) Density of intratumoral lymphocytes in mice segregated by housing temperature expressed as number of cells per megapixel (MP) of metastasis tissue. (E, F) Density of intratumoral lymphocytes in mice segregated by housing temperature and Sdc1 genotype (same dataset as in C, D). (G, H) Density of lymphocytes in normal lung tissue at distance from any metastases. (TIF 2897 kb)