Fig. 6

Expression of CARs with mutated CH2–CH3 domains. a Schematics of the CARs with different CH2–CH3 variants. An FMC63-based scFv with a signal peptide from CD33 was fused via a linker containing the amino acids GGGGSGGGGS (2 × G4S) and different CH2–CH3-spacer domains to a CD28/C3zeta-based CAR signaling backbone. The mutations are indicated (positions according to Uniprot IDs P01857 and P01861 of human IgG1 and IgG4, respectively). b Expression of the different CARs in anti-CD3/CD28-expanded T cells 1 day after electroporation of the respective mRNAs. Expression was detected via an anti-human-IgG antibody and analyzed by flow cytometry