Figure 4.

Intracellular staining for IFN-γ in immunized and tolerized DO.11 T cells. BALB/c recipients of DO.11 T cells were treated as in Fig. 2. CD4⁺ T cells were purified from lymph node cells. Lymph node cells were restimulated in vitro with 1 μg/ml OVA^323–339 peptide for 24 h, stained for expression of CD4, the DO.11, and intracellular IFN-γ as described in Materials and Methods, and analyzed by flow cytometry. The dot plots show expression of KJ-126 and IFN-γ in CD4⁺ T cells, and the histograms show the expression of IFN-γ in KJ-126⁺ CD4⁺ T cells (continuous black lines). Control stains are represented by the discontinuous grey lines.