Generation of OX40.ADR T cells and their activity in vitro. (A) Schematic of OX40.ADR structure. (B) Surface expression of OX40.ADR on primary human T cells on day 8 post transduction. Mean ± SD values are shown. Each dot represents data from an individual donor. (C) Ex vivo expansion kinetics of OX40.ADR T cells compared with donor-matched Ctrl T cells. Mean ± SD values from 6 individual donors are shown. P values were calculated using 2-way ANOVA followed with Sidak correction. Only P values < .05 (days 10 and 14) are shown. (D) Normalized residual counts of resting (left) or activated (right) primary human T cell targets after 48 hours of coculture with autologous Ctrl or ADR T cells. Mean ± SD values are shown. Each dot represents data from an individual donor. P values were calculated using 2-way ANOVA followed with Holm-Sidak correction. Not significant (ns), P ≥ .05. (E) Schematic of the MLR model for panels F-G. (F-G) Absolute cell counts of (F) CD3⁺ PBMC or (G) T cell receptor–edited (TCR^KO) T cells measured at indicated time points. Mean ± SD values are shown. P values were calculated using 2-way ANOVA followed with Sidak correction. Ctrl, control nontransduced T cells; ADR, OX40.ADR.