Figure 8.

Agonistic activity of an anti-VSTM3 mAb inhibits T-cell responses. mAb were coupled to beads (anti-CD3 at the indicated percentage of bead capacity and anti-VSTM3 mAb or an isotype-matched control antibody each at 80%) and the beads incubated at a bead: cell ration of 1:1 with purified T cells. Proliferation was judged by CFSE dilution on T cells (gated as indicated in the Supporting Information Fig. 5C) for anti-CD3 plus isotype control (left hand panels) or anti-CD3 plus anti-VSTM3 (center panels). Upregulation of CD25 was also assessed by FACS (right panels) using the beads coated with anti-CD3 plus the isotype control (dark line) or anti-CD3 plus anti-VSTM3 (grey line). Profiles shown are gated on CD4⁺ T cells (Supporting Information Fig. 5B), but similar results were obtained examining the same parameters on CD8⁺ cells in the same cultures. Results are representatives of at least three experiments.