Anti-CD19 CARs displayed at the surface of lentiviral vector particles promote transduction of target-expressing cells

Cordes, Nicole; Kolbe, Carolin; Lock, Dominik; Holzer, Tatjana; Althoff, Deborah; Schaefer, Daniel; Blaeschke, Franziska; Kotter, Bettina; Karitzky, Sandra; Rossig, Claudia; Cathomen, Toni; Feuchtinger, Tobias; Buerger, Iris; Assenmacher, Mario; Schaser, Thomas und Kaiser, Andrew D. (2021): Anti-CD19 CARs displayed at the surface of lentiviral vector particles promote transduction of target-expressing cells. In: Molecular Therapy-Methods & Clinical Development, Bd. 21: S. 42-53

Abstract

Recently, a rare type of relapse was reported upon treating a B cell acute lymphoblastic leukemia (B-ALL) patient with antiCD19 chimeric antigen receptor (CAR)-T cells caused by unintentional transduction of residual malignant B cells (CAR-B cells). We show that anti-CD19 and anti-CD20 CARs are presented on the surface of lentiviral vectors (LVs), inducing specific binding to the respective antigen. Binding of anti-CD19 CAR-encoding LVs containing supernatant was reduced by CD19-specific blocking antibodies in a dose-dependent manner, and binding was absent for unspecific LV containing supernatant. This suggests that LVs bind via displayed CAR molecules to CAR antigen-expressing cells. The relevance for CAR-T cell manufacturing was evaluated when PSPRINGER NATUREs and B-ALL malignant B cells were mixed and transduced with anti-CD19 or anti-CD20 CAR-displaying LVs in clinically relevant doses to mimic transduction conditions of unpurified patient leukapheresis samples. Malignant B cells were transduced at higher levels with LVs displaying anti-CD19 CARs compared to LVs displaying non-binding control constructs. Stability of gene transfer was confirmed by applying a potent LV inhibitor and long-term cultures for 10 days. Our findings provide a potential explanation for the emergence of CAR-B cells pointing to safer manufacturing procedures with reduced risk of this rare type of relapse in the future.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Sprache: Englisch