Antibody association with HER-2/neu–targeted vaccine enhances CD8⁺ T cell responses in mice through Fc-mediated activation of DCs
J. Clin. Invest. Peter S. Kim, et al. 118:1700 doi:10.1172/JCI34333 [Go to this article.]

Figure 3
CD11c⁺ DCs take up vaccine cells most efficiently in mice treated with the neu-expressing, GM-CSF–secreting vaccine given concurrently with the intact 7.16.4 mAb. (A) neu-specific antibody increased the uptake of vaccine cells by CD11c⁺ DCs in an Fc-dependent manner. neu-targeted vaccine (3T3 neu/GM) or control vaccine (3T3/GM) cells were labeled with PKH67 and then injected s.c. (1 × 10⁶ cells) into each limb of the mouse, followed by an i.p. injection of intact 7.16.4 mAb, 7.16.4 F(ab′)₂, or a control IgG Ab. The VDLNs were harvested daily on days 1–5 following treatment, and DCs were isolated using the Miltenyi CD11c magnetic beads. Plotted are the mean percentages of PKH67-expressing CD11c⁺ DCs for 4–5 mice per group. A representative flow cytometric analysis is shown for the neu-targeted vaccine + intact 7.16.4 mAb, + 7.16.4 F(ab′)₂, and + mIgG groups. *P < 0.05 versus all other treatment groups, Mann-Whitney U test. The statistical analysis is shown in Table 1. (B) CD11c⁺ DCs isolated from the neu-targeted vaccine and intact 7.16.4 mAb–treated mice expressed higher levels of the maturation markers B7-1, B7-2, CD40, MHC-II, and PD-L1 when compared with CD11c⁺ DCs isolated from mice treated with the neu-targeted vaccine + 7.16.4 F(ab′)₂ or + control antibody. Shown is a representative flow cytometric analysis of CD11c⁺ DCs isolated from 1 mouse per group. This experiment was repeated 3 times with similar results.