Preclinical evaluation of chimeric antigen receptor T cells targeting the carcinoembryonic antigen as a potential immunotherapy for gallbladder cancer

ABSTRACT

Gallbladder cancer (GBC) is commonly diagnosed at late stages when conventional treatments achieve only modest clinical benefit. Therefore, effective treatments for advanced GBC are needed. In this context, the administration of T cells genetically engineered with chimeric antigen receptors (CAR) has shown remarkable results in hematological cancers and is being extensively studied for solid tumors. Interestingly, GBC tumors express canonical tumor-associated antigens, including the carcinoembryonic antigen (CEA). However, the potential of CEA as a relevant antigen in GBC to be targeted by CAR-T cell-based immunotherapy has not been addressed. Here we show that CEA was expressed in 88% of GBC tumors, with higher levels associated with advanced disease stages. CAR-T cells specifically recognized plate-bound CEA as evidenced by up-regulation of 4-1BB, CD69 and PD−1, and production of effector cytokines IFN-γ and TNF-α. In addition, CD8⁺ CAR-T cells up-regulated the cytotoxic molecules granzyme B and perforin. Interestingly, CAR-T cell activation occurred even in the presence of PD-L1. Consistent with these results, CAR-T cells efficiently recognized GBC cell lines expressing CEA and PD-L1, but not a CEA-negative cell line. Furthermore, CAR-T cells exhibited in vitro cytotoxicity and reduced in vivo tumor growth of GB-d1 cells. In summary, we demonstrate that CEA represents a relevant antigen for GBC that can be targeted by CAR-T cells at the preclinical level. This study warrants further development of the adoptive transfer of CEA-specific CAR-T cells as a potential immunotherapy for GBC.

KEYWORDS:

• Gallbladder cancer
• Chimeric antigen receptor
• CAR
• Carcinoembryonic antigen
• CEA

Acknowledgments

This work was funded by: Centro Ciencia & Vida, FB210008, Financiamiento Basal para Centros Científicos y Tecnológicos de Excelencia from ANID - Agencia Nacional de Investigación y Desarrollo; Grants 1212070 and 11190897 from FONDECYT - Fondo Nacional de Desarrollo Científico y Tecnológico. Grants ID16I20369 and ID22I10070 from FONDEF - Fondo de Fomento al Desarrollo Científico y Tecnológico.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contributions

EL, SH, ER and JG performed CAR-T related experiments and analyzed the data. ES and CC performed the histological examination of GBC samples. CC and FSO analyzed and interpreted the GBC patient data. CHT, RP and MVG provided key material for carrying out the project. VB and AL supervised the project and interpreted the data. EL, VB and AL wrote the manuscript. All authors read and approved the final manuscript.

Data availability statement

The data that support the findings of this study are available from the corresponding author, [AL], upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/2162402X.2023.2225291

Additional information

Funding

The work was supported by the Agencia Nacional de Investigación y Desarrollo [FB210008]; Fondo Nacional de Desarrollo Científico y Tecnológico [FONDECYT 1212070]; Fondo Nacional de Desarrollo Científico y Tecnológico [FONDECYT 11190897]; Fondo de Fomento al Desarrollo Científico y Tecnológico [ID16I20369]; Fondo de Fomento al Desarrollo Científico y Tecnológico [ID22I10070].