Figure 3.

The frequency of double positive T cells does not increase following priming. Animals were primed i.p. with 2 mg alum-precipitated DNP–BSA in 0·5 ml PBS and were left for 1 week, unprimed animals received PBS alone. Mesenteric LN cells from unprimed (a–c) and primed (d–f) animals were triple labelled for TCRαβ (R73), CD4 (W3/25) and CD8α chain (OX8), CD8β chain (341) or a control mAb (OX21). R73⁺ cells were gated on and the expression of W3/25 against OX8, 341 or OX21 was analysed by flow cytometry. Numbers shown in the top right quadrants represent the percentage of T cells that were double labelled. Data are representative of two independent experiments.