Figure 2.

CD26^high CD8⁺ T cells are an early effector memory subset, as characterized by analysis of intracellular cytotoxic granules. Purified CD8⁺ T cells from peripheral blood mononuclear cells were stained with CD26, CD28, perforin (PRF), granzyme A (GzmA) and granzyme B (GzmB) monoclonal antibodies, and analysed by flow cytometry. Following gating for whole CD8⁺ population (brown lines in a), CD8⁺ CD26^high population (red lines in b), CD8⁺ CD26^int population (green lines in c), CD8⁺ CD26⁻ CD28⁺ population (blue lines in d), or CD8⁺ CD26⁻ CD28⁻ population (purple lines in e), each subset was analysed for the expression of PRF, GzmA or GzmB. The data are shown as histograms of PRF (i), GzmA (ii), or GzmB (iii) intensity among each subset, representative of eight independent donors. The black lines in each histogram show the data of isotype control.