Figure 4.

Effects of the Zap70^mrt/mrt mutation on T cells with a defined T-cell receptor (TCR). (a) Flow cytometric analysis of thymocytes from 3A9 TCR transgenic mice (H2^k/b) carrying the Zap70^mrt mutation. (b) Representative histograms of TCR-β and CD5 expression on CD4⁺ CD8⁺ thymocytes from Zap70^mrt/+ (solid grey histograms) and Zap70^mrt/mrt transgenic mice (unfilled histograms) (n = 2). (c) Thymocytes were stimulated in vitro for 15 hr with irradiated B10.Br (H2^k/k) splenocytes in the presence or absence of hen egg lysozyme (HEL) peptide, and flow cytometry was performed to measure CD69 induction on CD4⁺ CD8⁺ thymocytes. Representative histograms (left) and graphs (right) indicate mean ± standard deviation of CD69⁺ cells after no stimulation (grey bars, n = 2) or HEL stimulation (white bars, n = 2). (d) Mice were injected intraperitoneally with PBS, or 1 mg HEL in PBS, and thymi were collected 15 hr later. Flow cytometry was performed as in (c). Grey bars represent PBS control stimulation (n = 1), white bars represent HEL stimulation (n = 2). Data are from one independent experiment.