CD4+ and CD8+ T cells were isolated by negative selection from WT or EGR4-/-mice. (A) CD4+ and CD8+ T cells were loaded with Fura-2AM and plated on poly-D-lysine (2 hrs) before treating with biotinylated anti-CD3ε, followed by streptavidin where indicated. The average response of the majority of CD4+ (WT 74.2±3.2%; EGR4-/- 77.8±2.9%) and CD8+ (WT 79.4±3.5%; EGR4-/- 78.2±2.5%) cells that responded to streptavidin crosslinking of CD3 (mean±SEM; 40-60 cells/coverslip; 7 to 8 separate experiments). 