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Identification of Mediators of T-cell Receptor Signaling via the Screening of Chemical Inhibitor Libraries
Published on: January 22, 2019
Screening of kinase inhibitors downregulating PD-L1 expression via on/in cell quantitative immunoblots
Yongli Xie1, Jiwei Ding2, Xiangling Cui1
1Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua 321004, P. R. China; Chinese Academy of Medical Science, Institute of Medicinal Biotechnology, Beijing, China.
Abstract:
The interaction of programmed death-1 (PD-1) and it's ligands (PD-L1) is an important immune checkpoint and blockade of PD-1/PD-L1 axis with antibodies against PD-L1 showed promising anti-tumor activity in clinical practice. However, only a small percentage of patients can benefit from PD-L1 mAbs. Small molecular kinase inhibitors have been widely used as antitumor drugs for many years, and several kinase inhibitors were recently reported to inhibit the expression of PD-L1. However, the connections between PD-L1 expression and kinase inhibitors were not thoroughly elucidated. Herein, we set up a novel and robust screening system to identify small molecular compounds which downregulate the PD-L1 level of tumor cell based on Odyssey on/in cell quantitative immunoblots technology. A collected kinase inhibitor library was screened and 14 hits were further confirmed by western blot and flow cytometry. System biological analysis and further bio-assay identified a synergy combination between KU-60019 and Vacquinol-1 in downregulation of PD-L1. Taken together, the work established a novel method to screen the PD-L1 down-regulators using kinase inhibitors library, thus providing new clues for the application of kinase inhibitors in cancer immunotherapy.
Insights
This study developed a new method to screen for compounds that reduce programmed death-ligand 1 (PD-L1) in tumor cells. This approach identified potential new cancer immunotherapies using kinase inhibitors.
Area of Science:
- Immunology
- Oncology
- Pharmacology
Background:
- The programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) axis is a critical immune checkpoint targeted in cancer immunotherapy.
- While PD-L1 blockade antibodies show promise, only a subset of patients benefit, necessitating alternative therapeutic strategies.
- Kinase inhibitors, established anticancer agents, have demonstrated potential in modulating PD-L1 expression, but the underlying mechanisms require further elucidation.
Purpose of the Study:
- To establish a novel and robust screening system for identifying small molecules that downregulate PD-L1 levels in tumor cells.
- To screen a kinase inhibitor library to identify compounds capable of reducing PD-L1 expression.
- To investigate synergistic combinations of compounds for enhanced PD-L1 downregulation.
Main Methods:
- Development of a screening system utilizing Odyssey on/in cell quantitative immunoblots technology.
- Screening of a kinase inhibitor library, followed by confirmation of hit compounds using western blot and flow cytometry.
- System biological analysis and bio-assays to identify synergistic drug combinations.
Main Results:
- A novel screening platform was successfully established for identifying PD-L1 down-regulators.
- Fourteen kinase inhibitors were identified as hits that downregulate PD-L1 expression.
- A synergistic combination of KU-60019 and Vacquinol-1 was identified for enhanced PD-L1 downregulation.
Conclusions:
- The study presents a new method for screening PD-L1 down-regulating compounds from kinase inhibitor libraries.
- The findings provide new insights into the application of kinase inhibitors for enhancing cancer immunotherapy.
- The identified synergistic combination offers a potential strategy for improving treatment efficacy in cancer patients.
