FIGURE 6.

IFNγ production by CD4 T cells is necessary for their antitumor effect. A, Sorted anti-H-Y CD4 T Marilyn cells infiltrating the H-Y–expressing tumor MB49 were stimulated in vitro with TAMs sorted from untreated mice and cytokines were measured in the supernatants 24 hours later. Data show one of two experiments done. B, Survival of tumor-bearing mice was followed in three groups of mice; untreated (dashed line) and treated with Marilyn CD4 T cells in the presence of either anti-IFNγ blocking antibody (gray circles), or control rat IgG1 antibody (pink circles). Representative experiment from two done. C, As in B, this time comparing untreated mice (discontinuous line) with mice treated with either wild-type (pink circles) or IFNγ KO (gray diamonds) Marilyn CD4 T cells. D–E, TAMs from untreated (open circles), or CD4-treated mice receiving either control IgG1 antibody (pink circles) or anti-IFNγ blocking antibody (gray circles) were purified and their phenotype and function measured as in Fig. 4. D, Mean fluorescent intensity of CD206 on TAMs measured by flow. Data pooled from two independent experiments. E, Sorted TAMs were cultured overnight and proteins measured in the supernatants. Included are TAMs from untreated or CD4-treated RAG/IFNγRdKO mice (triangles). Data pooled from three independent experiments. D–E, Individual circles represent TAMs from individual mice. Horizontal lines are the medians in each experimental group. B–C, *, P < 0.05; ***, P < 0.001, using log-rank test. D–E, *, P < 0.05; **, P < 0.01, using Kruskal–Wallis with Dunn as post-test.