Fig. 2. 4-1BB-based mCAR T cells specifically targeting the IGLV3-21^R110 neoepitope.

a NALM6 pre-B cells expressing luciferase were left untreated (Luc) or transfected with a lentiviral vector encoding for the IGLV3-21^R110 light chain (LC) (NALM-6 Luc-R110) or its wild-type non-pathogenic IGLV3-21^G110 counterpart (NALM-6 Luc-G110). Representative dot plots show expression of surface BCRs containing the transfected LCs. BFP, blue fluorescent protein. b Schematic representation of the 4-1BB-based anti-IGLV3-21^R110 murine CAR construct (αR110-mCAR2). scFv single chain variable fragment, TMD transmembrane domain, ICD intracellular domain. Created with BioRender.com. c Percentage of positive CAR T cells from one representative donor and (d) from several donors pooled (n = 5 HDs). e Percent tumor cell lysis based on a bioluminescence assay after 12 h co-culture of NALM-6 Luc expressing IGLV3-21^R110 or its non-pathogenic counterpart IGLV3-21^G110 in an effector to target (E:T) ratio of 5:1. (n = 4 HDs). f–h Expression of activation markers by CAR T cells alone or after 24 h of stimulation with the indicated target cells (1:1 ratio). (n = 3 HDs). UTDs untransduced T cells. Mock, T cells transduced with the same lentiviral vector but expressing only GFP (green fluorescent protein). All bar plots represent the indicated mean ± SD. n, indicates independent experiments/donors. Statistics: One-way ANOVA followed by t test with Welch’s correction. Source data are provided as a Source Data file.