APC conditioning by high- and low-avidity T cells. (A) GAD-pulsed B cells were incubated for 12 hours with sorted Ann-V^- high- or low-avidity T cells that had been previously treated with either control TMr (dashed lines) or GAD TMr (black lines). B cells were subsequently gated and analyzed by flow cytometry. (B) The same experiment was performed with unpulsed B cells. (C) GAD-pulsed DCs were incubated as described with sorted Ann-V^- high- or low-avidity T cells that had been previously treated with either control or GAD TMr, as indicated. Flow cytometry analysis of gated DCs incubated with the indicated T cells (black lines) is shown in comparison with gated DCs cultured alone (dashed lines).