Figure 7.
T reg cell depletion is mediated largely by FcγRIV. (A and B) Wild-type and γ−/− mice were challenged with B16-BL6 and treated as described in Fig. 2. Absolute cell numbers and Foxp3 expression by intratumoral CD4+CD45.1+ Trp1 (A) and CD4+CD45.1− endogenous polyclonal T cells (B). n = 9–10 mice per group. (C) SPR analysis of α–CTLA-4 clone 9H10 binding to FcγRI, FcγRIII, and FcγRIV. (D and E) Wild-type, FcγRIII−/−, and FcγRIV−/− mice were challenged with B16-BL6 and treated as described in Fig. 2. Absolute cell numbers and Foxp3 expression by intratumoral CD4+CD45.1+ Trp1 (D) and CD4+CD45.1− endogenous polyclonal T cells (E). (F) SPR analysis of three different α–CTLA-4 clones (4F10, 9D9, 9H10) binding to FcγRIV. n = 7–10 mice per group. *, P < 0.05; **, P < 0.01; ***, P < 0.001. Experiments were repeated three times and pooled.