In vitro characteristics of mLSTs. Leukemia TAA-directed activity of nonmanipulated donor lymphocytes (A) and ex vivo expanded mLSTs (B). Mean ± SEM. mLSTs did not kill normal recipient cells (C), but killed TAA-pulsed normal cells tested at E/T ratios from 80:1 to 5:1 (D). Mean ± SEM. Polyclonality of mLSTs, as assessed by TCR-vβ deep sequencing (E) and immunophenotyping (F). (C,E-F) Each symbol represents an individual product.