T cell responses in CCR2^−/− mice. (A) mRNA expression of iNOS and ARG1 in the tumor of WT or CCR2^−/− mice was analyzed by RT-PCR. (B) Percentage of CD4⁺ cells, CD8⁺ cells, and NK1.1⁺ cells in CD45⁺ leukocytes from tumors of WT or CCR2^−/− mice was analyzed by flow cytometry. (C) Number of CD4⁺ cells, CD8⁺ cells, and Foxp3⁺CD4⁺ cells in the draining LNs of WT or CCR2^−/− mice was analyzed by flow cytometry. (D) Ex vivo IFN-γ production of CD8 T cells from tumor-draining LNs and nondraining LNs of WT or CCR2^−/− mice was analyzed by flow cytometry. Dotted line indicates no-stimulation background. Graphs represent the mean (± SD) of 3 to 5 mice. *P < .05; **P < .01. Representative of 2 independent experiments.