Enrichment of TCR/CD3 complex and of p56^lck at the T cell/PCMC_IFN-γ/IL-4 contact site. IFN-γ/IL-4–primed PCMCs were pulsed or not with 10 μg/mL OVAp. After washing, APCs were cocultured with effector OT-II T cells for 10 minutes. Cells were settled onto polylysine-coated slides, fixed, and stained for mast cell granules with avidin-sulforhodamine 101 (red), CD3ϵ (green), and p56^lck (blue). (A) Representative staining for CD3ϵ (green), and p56^lck (blue) of a PCMC_IFN-γ/IL-4/OT-II T-cell conjugate. Staining is represented merged with DIC images; p56^lck staining is also shown as pseudocolor intensity. (B) OT-II T cell/PCMC conjugates were randomly selected and scored for the recruitment of p56^lck to the cell-cell contact site either alone or in combination with CD3ϵ. indicates conjugates exhibiting recruitment of p56^lck alone; ■, conjugates exhibiting polarization of both p56^lck and CD3ϵ; □, conjugates exhibiting neither p56^lck nor CD3 polarization. Approximately 100 conjugates were analyzed per experiment. Histograms represent means ± SEM of 3 independent experiments. Bar = 5μm.