Extended Data Fig. 5: Persistence of β-Lac enzyme activity and Ceph-AMS prodrug activation in mouse intraperitoneal Raji tumor xenografts after SEAKER cell exhaustion in vivo.
From: Engineering CAR-T cells to activate small-molecule drugs in situ
(a) Experimental scheme for rescue of relapsed Raji xenograft by treatment with Ceph-AMS (3: 4 mg/kg, ip, bid, days 4–5, 3 doses total, then days 22–23 (gray bar), 3 doses total) after exhaustion of β-Lac-19BBz SEAKER cells. (b) Quantitation of tumor bioluminescence before and after second dosing period (median with s.d. of n = 4 mice per group; experiment was performed once). (c) Persistence of β-Lac enzyme activity in β-Lac-19BBz SEAKER cells extracted from two of the mice from the experiment in panel a at day 30 (day 28 post administration), in comparison to standard 19BBz CAR-T cell controls (flow cytometry analysis: β-Lac substrate = CCF2-AM).
