TY - JOUR
T1 - Combined CD28 and 4-1BB costimulation potentiates affinity-tuned chimeric antigen receptor-engineered t cells
AU - Drent, Esther
AU - Poels, Renée
AU - Ruiter, Ruud
AU - van de Donk, Niels W. C. J.
AU - Zweegman, Sonja
AU - Yuan, Huipin
AU - de Bruijn, Joost
AU - Sadelain, Michel
AU - Lokhorst, Henk M.
AU - Groen, Richard W. J.
AU - Mutis, Tuna
AU - Themeli, Maria
N1 - Funding Information: The H2d-Rag2−/−gc−/− mice used in this study were originally obtained from the Amsterdam Medical Center (AMC, Amsterdam, the Netherlands). This work is in part financially supported by `Fonds Stimulans' the Netherlands (to E. Drent), the European Commission (Marie Curie Individual Fellowship, to M. Themeli), and Stichting VUmc CCA (to M. Themeli). Publisher Copyright: © 2019 American Association for Cancer Research. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Purpose: Targeting nonspecific, tumor-associated antigens (TAA) with chimeric antigen receptors (CAR) requires specific attention to restrict possible detrimental on-target/off-tumor effects. A reduced affinity may direct CAR-engineered T (CART) cells to tumor cells expressing high TAA levels while sparing low expressing normal tissues. However, decreasing the affinity of the CAR-target binding may compromise the overall antitumor effects. Here, we demonstrate the prime importance of the type of intracellular signaling on the function of lowaffinity CAR-T cells. Experimental Design: We used a series of single-chain variable fragments (scFv) with five different affinities targeting the same epitope of the multiple myeloma-associated CD38 antigen. The scFvs were incorporated in three different CAR costimulation designs and we evaluated the antitumor functionality and off-tumor toxicity of the generated CAR-T cells in vitro and in vivo. Results: We show that the inferior cytotoxicity and cytokine secretion mediated by CD38 CARs of very low-affinity (K d < 1.9 × 10 -6 mol/L) bearing a 4-1BB intracellular domain can be significantly improved when a CD28 costimulatory domain is used. Additional 4-1BB signaling mediated by the coexpression of 4-1BBL provided the CD28-based CD38 CAR-T cells with superior proliferative capacity, preservation of a central memory phenotype, and significantly improved in vivo antitumor function, while preserving their ability to discriminate target antigen density. Conclusions: A combinatorial costimulatory design allows the use of very low-affinity binding domains (K d < 1 mmol/L) for the construction of safe but also optimally effective CAR-T cells. Thus, very-low-affinity scFvs empowered by selected costimulatory elements can enhance the clinical potential of TAA-targeting CARs.
AB - Purpose: Targeting nonspecific, tumor-associated antigens (TAA) with chimeric antigen receptors (CAR) requires specific attention to restrict possible detrimental on-target/off-tumor effects. A reduced affinity may direct CAR-engineered T (CART) cells to tumor cells expressing high TAA levels while sparing low expressing normal tissues. However, decreasing the affinity of the CAR-target binding may compromise the overall antitumor effects. Here, we demonstrate the prime importance of the type of intracellular signaling on the function of lowaffinity CAR-T cells. Experimental Design: We used a series of single-chain variable fragments (scFv) with five different affinities targeting the same epitope of the multiple myeloma-associated CD38 antigen. The scFvs were incorporated in three different CAR costimulation designs and we evaluated the antitumor functionality and off-tumor toxicity of the generated CAR-T cells in vitro and in vivo. Results: We show that the inferior cytotoxicity and cytokine secretion mediated by CD38 CARs of very low-affinity (K d < 1.9 × 10 -6 mol/L) bearing a 4-1BB intracellular domain can be significantly improved when a CD28 costimulatory domain is used. Additional 4-1BB signaling mediated by the coexpression of 4-1BBL provided the CD28-based CD38 CAR-T cells with superior proliferative capacity, preservation of a central memory phenotype, and significantly improved in vivo antitumor function, while preserving their ability to discriminate target antigen density. Conclusions: A combinatorial costimulatory design allows the use of very low-affinity binding domains (K d < 1 mmol/L) for the construction of safe but also optimally effective CAR-T cells. Thus, very-low-affinity scFvs empowered by selected costimulatory elements can enhance the clinical potential of TAA-targeting CARs.
UR - http://www.scopus.com/inward/record.url?scp=85068349459&partnerID=8YFLogxK
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068349459&origin=inward
UR - https://www.ncbi.nlm.nih.gov/pubmed/30979735
U2 - https://doi.org/10.1158/1078-0432.CCR-18-2559
DO - https://doi.org/10.1158/1078-0432.CCR-18-2559
M3 - Article
C2 - 30979735
SN - 1078-0432
VL - 25
SP - 4014
EP - 4025
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 13
ER -