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

Molecular Therapy: Methods & Clinical Development

Carolin Kolbe¹  Andrew D. Kaiser¹  Toni Cathomen¹  Franziska Blaeschke¹  Deborah Althoff¹  Iris Bürger¹  Sandra Karitzky¹  Dominik Lock²  Mario Assenmacher³  Thomas Schaser⁴  Daniel Schäfer⁴  Tatjana Holzer⁴  Tobias Feuchtinger⁴  Bettina Kotter⁴  Claudia Rossig⁴  Nicole Cordes⁴ 

[1] Co. KG, 51429 Bergisch Gladbach, Germany;Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany;Department of Pediatric Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Dr. von Hauner Children’s Hospital, University Hospital, LMU Munich, 80337 Munich, Germany;;Miltenyi Biotec B.V. &

关键词: CAR-T;    CAR-B;    immunotherapy;    lentiviral vector;    CAR display;    CAR-T cell resistance;   

DOI  :  

来源: DOAJ

【 摘 要 】

Recently, a rare type of relapse was reported upon treating a B cell acute lymphoblastic leukemia (B-ALL) patient with anti-CD19 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 PBMCs 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.

【 授权许可】

Unknown