hTERT-siTCR–transduced CD8⁺ T cells kill freshly isolated ATL cells and newly HTLV-I–infected CD4⁺ T cells, but not normal cells, in vitro. (A) Freshly isolated HLA-A*24:02⁺ (n = 3) or HLA-A*24:02⁻ (n = 3) ATL tumor cells overexpressing hTERT mRNA were used as targets in ⁵¹Cr-release assays with hTERT-siTCR–transduced CD8⁺ T cells at the indicated E/T ratios. (B) The same hTERT-siTCR–transduced CD8⁺ T cells used in panel A at the same E/T ratios were tested in ⁵¹Cr-release assays against newly generated HLA-A*24:02⁺ HTLV-I–infected CD4⁺ T cells (n = 2) representing HTLV-I carrier CD4⁺ T cells, original HLA-A*24:02⁺ normal CD4⁺ T cells (n = 2) representing the normal counterpart ATL tumor cells (corresponding number indicating cells from the identical donor), and HLA-A*24:02⁺ normal CB-CD34⁺ cells (n = 2) encompassing steady-state normal hematopoietic progenitor cells. Listed levels of expression of hTERT mRNA are those relative to the mean levels of expression across 6 PBMC samples from healthy donors determined by qRT-PCR and calculated by using the comparative threshold cycle method. Error bars represent SDs (* indicates less than detectable).