Figure 10.

TNFSF4/OX40L up-regulation in AZA-primed leukemia cells promotes CAR T cell function (continued). (A) Co-culture with target cells increased proportion of OX40⁺ CAR T cells. OX40 and CAR expression were analyzed in CD3⁺ gate (top panel). Proportions of OX40⁺ CAR T cells in 24-hour co-cultures with ALL-2 cells (bottom panel). (B) High OX40 expression in CAR T cells is associated with the increased proportion of activated FSC^high cells (right panel). Representative dot plot analysis of OX40 versus FSC T cells in the CD3⁺ gate is shown (left panel). CAR T cells co-cultured with leukemia cells at E:T = 20:1, 10:1, 1:1 (24 hrs). (C) Reduced proportion of OX40L⁺ CD10⁺ target cells following co-culture with CAR T cells. OX40L blockade increased the proportion of OX40L⁺ target cells preserved from CAR T cell killing. Representative flow cytometry analysis for each condition is shown (bottom panel). OX40L-blocking antibodies and the antibodies used for detecting OX40L expression bound to different OX40L epitopes.