Figure 2.
(A) Decay of TCR from T cells upon conditional Cα deletion. Flow cytometric determination of TCRβ expression on CD4+ (Left) and CD8+ (Right) peripheral blood T cells. Days after the injection of pI/pC and percentages of T cells with down-regulated TCRβ are indicated. (B) Simultaneous decay of CD3 complex with TCRβ on Cα-deleted T cells. Dot plot represents CD5-gated peripheral blood lymphocytes on day 15 after injection of pI/pC. Cells were analyzed for surface CD3ɛ and TCRβ expression by flow cytometry. (C) Southern blot analysis of TCR+ and TCR− T cells. TCR+ and TCR− subsets of CD4+ and CD8+ T cells isolated from the spleen of Cαfl/− mice 10 days after the injection of pI/pC were sorted, and genomic DNA was analyzed for Cα deletion. BamHI-digested DNA was hybridized with probe A (see Fig. 1A). Bands indicate TCRα−/− (6.9 kb), Cα-deleted (CαΔ, 6.7 kb), and Cαfl (10.9 kb) alleles.