Anti-PD-L1 × anti-CD3 bispecific T-cell engager-armed T cells can overcome immunosuppression and redirect T cells to kill breast cancer cells expressing PD-L1

• Published in: International immunopharmacology 2023-11, Vol.124, p.111012-111012, Article 111012
• Main Authors: Luangwattananun, Piriya, Sangsuwannukul, Thanich, Supimon, Kamonlapat, Thuwajit, Chanitra, Chieochansin, Thaweesak, Sa-nguanraksa, Doonyapat, Samarnthai, Norasate, O-Charoenrat, Pornchai, Junking, Mutita, Yenchitsomanus, Pa-thai
• Format: Article
• Language: English
• Subjects: Adoptive cell therapy; Bispecific T-cell engager-armed T cells; Breast cancer; PD-L1; PD1
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2023.111012

•Anti-PD-L1 × anti-CD3 bispecific T-cell engagers (BTEs) were produced from CHO cells.•The BTEs were used to arm T cells to generate BTE-armed T cells (BATs).•BATs allow blockage of PD-L1/PD-1 and redirect T cells to kill PD-L1 + cancer cells.•Cryopreserved BATs retained stability, supporting their use and transportation. T cell-based immunotherapy has transformed cancer treatment. Nonetheless, T cell antitumor activity can be inhibited by an immune checkpoint molecule expressed on cancer cells, program death ligand 1 (PD-L1), which interacts with the PD-1 on T cells. We generated αPD-L1 × αCD3 bispecific T-cell engager-armed T cells (BATs) to prevent PD-L1/PD-1 interaction and hence to redirect T cells to kill cancer cells. αPD-L1 × αCD3 bispecific T-cell engagers (BTEs) were produced from Chinese hamster ovary (CHO) cells to arm human primary T cells. Flow cytometry was used to investigate BTE binding to BATs. The cytotoxicity of BATs against PD-L1-expressing breast cancer (BC) cell lines was assessed in 2-dimensional (2D) and 3-dimensional (3D) culture models. The binding stability of BTE on BATs and their efficacy after cryopreservation were also examined. The CHO cell BTE expression yield was 3.34 mg/ml. The binding ability on T cells reached 91.02 ± 4.2 %. BATs specifically lysed PD-L1-expressing BC cells, with 56.4 ± 15.3 % HCC70 cells and 70.67 ± 15.6 % MDA-MB-231 cells lysed at a 10:1 effector-to-target ratio. BATs showed slight, nonsignificant lysis of PD-L1-negative BC cells, MCF-7, and T47D. Moreover, BATs significantly disrupted MDA-MB-231 3D spheroids expressing PD-L1 after 48 and 72 h of coculture. Cryopreserved BATs maintained BTE binding stability, cell viability, and anticancer activity, comparable to fresh BATs. αPD-L1 × αCD3 BATs induced the cytolysis of PD-L1-expressing BC cells in 2D and 3D coculture assays. BATs can be prepared and preserved, facilitating their use and transportation. This study demonstrates the potential of αPD-L1 × αCD3 BATs in treating cancers with positive PD-L1 expression.