CP-1 exhibits balanced, dual-nanomolar inhibitory activity against PD-L1 and CD73 and displays potent immunomodulatory effects at the cellular level and serves as a promising lead candidate for developing novel bifunctional agents to advance tumor immunotherapy.
Abstract
Objectives This work aims to design and characterize a novel bifunctional small molecule that simultaneously targets PD-L1 and CD73 to enhance the therapeutic efficacy of tumor immunotherapy. Methods Multiple methodologies were integrated for compound screening and biological characterization, including computer-aided molecular docking, homogeneous time-resolved fluorescence (HTRF) binding assay, surface plasmon resonance (SPR), and PD-1/PD-L1 NFAT reporter cell assay. Results The lead compound CP-1 exhibited potent dual-target inhibitory activities. It blocked the PD-1/PD-L1 interaction with an IC50 of 10.27 nM and suppressed CD73 activity with an IC50 of 300.2 nM. Molecular docking simulations revealed that CP-1 stably binds to the functional domains of PD-L1 and CD73 via specific non-covalent interactions. Cellular functional assays further demonstrated that CP-1 effectively restored T cell function in the PD-1/PD-L1 reporter system, with an EC50 of 0.9 μM. Conclusions CP-1 exhibits balanced, dual-nanomolar inhibitory activity against PD-L1 and CD73 and displays potent immunomodulatory effects at the cellular level. It serves as a promising lead candidate for developing novel bifunctional agents to advance tumor immunotherapy.
PE-1 demonstrates dual-target inhibitory activity against the PD-1/PD-L1 immune checkpoint and EZH2, underscoring its potential as a lead compound for the development of next-generation bifunctional anticancer agents.
B. Guan, Binbin Cheng, Hongqiao Li· Frontiers in Immunology· 0 citations
Background/Objectives: Recent advances in immunotherapy have revolutionized cancer treatment, as exemplified by multiple monoclonal antibodies against programmed cell death protein 1 (PD-1) or programmed death-ligand 1 (PD-L1). Nevertheless, immunotherapeutic antibodies exhibit certain limitations, which drives the development of alternative approaches, such as small interfering RNA (siRNA)-based therapeutics. The aim of this study was to design and produce new biological PD-L1 siRNA (BioRNA/PD-L1-siRNA) molecules and further define their immunotherapeutic efficacy against non-small cell lung cancer (NSCLC) in vitro. Methods: A novel RNA molecular bioengineering platform was employed to produce new BioRNA/PD-L1-siRNA agents. The functions of BioRNA/PD-L1-siRNAs were determined by quantitative PCR, Western blot, immunofluorescence confocal imaging, flow cytometry, and PD-1/PD-L1 blockade assays in human NSCLC cells, alone and co-cultured with human peripheral blood mononuclear cells (PBMCs). Results: After heterologous overexpression and purification of five BioRNA molecules, one siRNA named BioRNA/PD-L1-siRNA-1 was identified as the most effective to selectively suppress human PD-L1 mRNA and protein levels in H460 and H1975 cells. Disruption of PD-1/PD-L1 interactions by BioRNA/PD-L1-siRNA-1 was further demonstrated via a PD-1/PD-L1 blockade bioassay. In addition, the immunomodulatory effectiveness of BioRNA/PD-L1-siRNA-1 was established in co-culture models, as indicated by the induction of T-cell and natural killer cell populations and an increase in specific cytokines and cytotoxic granules, and subsequent enhancement of apoptosis and greater inhibition of NSCLC cell viability. Conclusions: Overall, these findings demonstrate the potential of bioengineered PD-L1 siRNA entities for NSCLC immunotherapy.
N. Batra, Mei-Juan Tu, Su Guan et al.· Non-Coding RNA· 0 citations
Cell-based assays showed that SA13 can mediate the internalization of PD-L1 and strongly block hPD-1 and hPD-L1 interaction, demonstrating its effectiveness in biological events and indicating that SA13 is a promising and safe novel antitumor agent worthy of further development.
Jianwei Wang, Shenwei Yu, Liang Qian et al.· Journal of Medicinal Chemist...· 0 citations
Blocking the PD-1/PD-L1 (Programmed Cell Death Protein-1/Programmed Cell Death Ligand-1) pathway represents a pivotal approach in cancer immunotherapy, effectively promoting sustained antitumor immune responses while alleviating immunosuppressive mechanisms. Advancing novel technologies to enhance the efficacy of PD-1/PD-L1 blockade remains a critical focus in medical research. Nonetheless, challenges such as immune-related adverse effects, therapeutic resistance, and high treatment costs highlight the urgent need for innovative strategies that optimize clinical outcomes and accessibility. Aptamers are short, single-stranded oligonucleotides characterized by their high affinity and specificity for target molecules. Emerging as promising alternatives to traditional antibody-based therapies, they offer new avenues in cancer treatment. This review provides a comprehensive analysis of aptamer-driven strategies aimed at inhibiting the PD-1/PD-L1 immune checkpoint pathway. It summarizes recent advances in the design of PD-1/PD-L1-targeted aptamer systems and evaluates their potential to enhance therapeutic efficacy while addressing challenges related to immune resistance.
Abolfazl Marvizadeh, Elham Sameiyan, Amir Teymour Najjarkar et al.· International Journal of Bio...· 0 citations
Background/aim: Targeted therapies with monoclonal antibodies provide cancer patients with better prognosis and diseasefree survival. The blockade of immune checkpoints, including programmed cell death protein-1 (PD-1) and its ligand PD-L1, with monoclonal antibodies may boost immune responses against tumors and is regarded as an effective strategy in cancer immunotherapy. We describe the generation of anti-PD-L1 monoclonal antibodies with high affinity and specificity, and we assess their potential for therapeutic use in cancer.
Materials and methods: Hybridomas were selected for PD-L1 specificity and cross-reactivity with other immune checkpoint proteins and PD-L1 orthologs using indirect ELISA. Immunofluorescence and Western blotting assays were conducted for further characterization of the antibodies. The affinities of the antibodies for PD-L1 were determined using surface plasmon resonance. Receptor blocking activities were examined through competitive ELISA and cell-based luciferase reporter assays. Sequences of variable regions of the selected antibodies were determined by Sanger sequencing and subjected to BLAST analysis.
Results: A total of 25 PD-L1-specific monoclonal antibodies were generated. While most clones reacted with PD-L1 from cynomolgus monkeys, none of the antibodies displayed cross-reactivity with other checkpoint proteins. Immunofluorescence assays showed that the selected clones stained PD-L1-expressing cell membranes specifically, but not those of PD-L1-negative cells. Western blotting revealed that most of the clones recognized both glycosylated and nonglycosylated PD-L1, and a few reacted with the glycosylated form only. Only two clones with subnanomolar affinity for human PD-L1 were effective at blocking PD-1/PD-L1 and CD80/PD-L1 interactions. Sequence analysis of their variable regions revealed their unique specificity.
Conclusion: Of the 25 monoclonal antibodies produced in this study, only one was identified as a potential therapeutic drug candidate thanks to its high capacity for checkpoint blockade and affinity, as well as its unique sequence specificity. These properties are comparable to those of anti-PD-L1 antibodies currently used in clinical practice.
Nurşah Ersezen, Maide Şeker, Arzu Aysan et al.· Turkish Journal of Biology· 0 citations
To address challenges such as the complex manufacturing of CAR-T and the immunosuppressive tumor microenvironment (TME), CAR-NK cells offer greater potential as an “off-the-shelf” therapy. To broaden tumor recognition and reduce the risk of immune escape associated with single-target approaches, we developed a single-promoter-driven multicistronic CAR-NK92 system that employs NKG2D for broad recognition of stress ligands and combines a PD1-CAR to reverse PD-L1 inhibitory signaling, thereby significantly enhancing antitumor efficacy. A multicistronic construct co-expressing PD1-CAR and NKG2D-CAR was generated using a P2A peptide under the control of a single CMV promoter and introduced into NK92 cells. The expression of PD-L1 and MICA/B was screened across multiple tumor cell lines, and the functional robustness of PN-CAR-NK92 cells was evaluated in all models through in vitro cytotoxicity and cytokine secretion assays. The in vivo translational efficacy was further validated using an H1299 xenograft model, with a direct comparison between PN-CAR-NK92 cells and NK92 cells. The multicistronic design enabled stable surface co-expression of both receptor modules, providing a structural basis for dual-target functionality. In vitro cytotoxicity assays demonstrated that PN-CAR-NK92 cells maintained robust antitumor activity across tumor cell lines with distinct PD-L1 and MICA/B expression profiles, whereas single-target CAR-NK92 cells displayed more restricted target specificity. These findings suggest that dual-target CAR engineering broadens antigen recognition coverage and may help reduce the limitations associated with single-target antigen dependence. Furthermore, PN-CAR-NK92 cells demonstrated significantly enhanced tumor suppression in the H1299 xenograft model compared with control groups. Dual-target PD1/NKG2D CAR-NK92 cells exhibit broadened antitumor activity across tumor cells with distinct ligand-expression profiles and may represent a promising strategy to reduce the limitations associated with single-target CAR therapies.
Xinru Jin, Mingfeng Li, Mengjun Wang et al.· Journal of Translational Med...· 0 citations