Fig. 5.

Classical cytotoxic T lymphocytes (CTL) bearing CD8 and αβTCR are the main cytotoxic cells against Sézary cells in the Sézary syndrome (SzS) patient. (a) The representative CTL clone generated from cultured CD8⁺ cells at a time point A was phenotyped by flow cytometric analysis using fluorescein-conjugated anti-αβTCR (- - - -), -CD4 (… …), -CD8 (– - − - –), and control mouse IgG MoAbs (–. −. –). (b) Cytotoxicities of eight CTL clones were assayed by ⁵¹Cr-release of labelled Sézary cells at the indicated effector/target ratio. Data are dot-plotted as average of the results of duplicated experiments. (c) Cytotoxicity inhibition assays of representative CTL clone using anti-αβTCR, -pan HLA class I, -CD4 and -CD8 MoAbs were performed. Cytotoxicity was assayed by ⁵¹Cr-release of labelled Sézary cells at an effector/target ratio of 1. Anti-αβTCR (▪), -pan HLA class I (•), -CD4 (○) and -CD8 (□) MoAbs were added at the start of the cytotoxic assay at the indicated concentrations. Mouse IgG MoAb (Δ) was used as a control antibody. Data are expressed as mean ± s.e.m. of the results of duplicate experiments.