Fig. 4: Anti-TACI CARs are functional against BCMA negative multiple myeloma but lose efficacy against TACI negative tumor.
From: Anti-TACI single and dual-targeting CAR T cells overcome BCMA antigen loss in multiple myeloma
a BCMA and TACI flow cytometry staining of MM1S Cas9+ WT and BCMA KO cells. b Luciferase-based cytotoxicity assay of MM1S BCMA KO cell line targeted by anti-TACI or BCMA CAR T cells at the indicated E:T ratios after 18 h of coculture (n = 3ND+/– SEM in biological triplicate, unpaired t tests at each ratio where **=0.005797 between anti-BCMA and anti-TACI H-L and 0.001331 between anti-BCMA and anti-TACI L-H and 0.001224 between anti-TACI H-L and anti-TACI L-H at a 10:1 E:T and **=0.002689 between anti-TACI H-L and anti-TACI L-H at a 3:1 E:T). Calculated as a percentage of luminescence of tumor only wells. c Schematic of MM1S BCMA KO curative model treated with 5e6 CAR+ cells. d BLI imaging of c. e Quantified BLI of c (5 mice per group +/– SEM, experiment representative of 3 separate experiments each treated with a different ND, unpaired t test to Untransduced at day 31 where **=0.002040 for anti-TACI H-L and **=0.005764 for anti-TACI L-H). f BCMA and TACI flow cytometry staining of TACI KO MM1S Cas9+ cells. g Luciferase-based cytotoxicity assay of MM1S Cas9+ TACI KO cell line targeted by anti-TACI or BCMA CAR T cells at the indicated E:T ratios after 18 h of coculture (n = 3ND+/– SEM in biological triplicate, unpaired t tests at each ratio where *=0.045779). Calculated as a percentage of luminescence of tumor only wells. Raw data is provided in the Source Data file. All tests are two-sided. p = ****<0.0001.
