Fig 5. Experimental design of cell survival assay.

PBMCs from each of 9 ATL patients with a dominant ATL clone detectable by TCRVβ staining were depleted of CD8⁺ T cells. The CD8⁻ PBMCs (CADM1⁺CD4⁺, purple; CADM1⁻CD4⁺, yellow) were cultured overnight either alone or in the presence of autologous CD8⁺ cells at a range of ratios, after which cells were stained with a viability stain and antibodies specific for CD3, CD4, CD8, CADM1 and the TCRVβ subunit which was most frequently used in that individual (‘TCRVβX’). Cells were then permeabilised, stained intracellularly with anti-Tax antibody, and analysed by flow cytometry. Absolute cell counts of CD3⁺, CD4⁺ and CD8⁺ cells were performed in parallel.