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Development of a fluorescent probe for the detection of hPD-L1
Xinyu Li1, Xiaoming Huang1, Liqian Zhang1
1Key Laboratory for Biological Medicine in Shandong Universities, Weifang Key Laboratory for Antibody Medicine, School of Life Science and Technology, Weifang Medical University, Weifang 261053, China.
Abstract:
Interaction of human programmed death factor-1 (hPD-1) of T cells and one of its ligands hPD-L1 which is expressed on cancer cells suppresses effector T cell functions. Studies showed that the hPD-1/hPD-L1 pathway is associated with killing mechanisms of tumor cells evading the immune system. Immunotherapy based on the checkpoint inhibitor on hPD-1 has been an important approach to treat cancer; however, not all cancer cells over-express hPD-L1. Detection of hPD-L1 over-expression in cancer cells may be a key factor for deciding on whether immunotherapy should be conducted. In the present study, we produced recombinant hPD-1 using Escherichia coli, and created a fluorescent probe termed quenched hPD-1 (QPD-1) for the detection of hPD-L1. We found that hPD-1 can quench fluorescence of carboxytetramethylrhodamine labeled on its N-terminal and QPD-1 is a convenient tool to rapidly detect hPD-L1 with a limit of detection of 10 nM and detectable range of 10 nM-1000 nM. QPD-1 may also function as a probe to screen for hPD-L1 over-expressing tumor cells and promote appropriate medical procedure through tumor immunotherapy.
Insights
A novel fluorescent probe, quenched human programmed death-1 (QPD-1), rapidly detects human programmed death-ligand 1 (hPD-L1) on cancer cells. This tool aids in identifying candidates for immunotherapy by detecting hPD-L1 overexpression.
Area of Science:
- Biotechnology
- Immunology
- Cancer Research
Background:
- The human programmed death-1 (hPD-1) and its ligand hPD-L1 pathway on T cells and cancer cells, respectively, suppresses anti-tumor immune responses.
- This immune evasion mechanism is a target for cancer immunotherapy, but efficacy depends on hPD-L1 expression levels in tumors.
Purpose of the Study:
- To develop a rapid and convenient method for detecting hPD-L1 expression on cancer cells.
- To create a tool that can assist in selecting patients for hPD-1 based immunotherapy.
Main Methods:
- Production of recombinant human programmed death-1 (hPD-1) using Escherichia coli.
- Development of a fluorescent probe, quenched hPD-1 (QPD-1), by labeling hPD-1 with carboxytetramethylrhodamine.
- Evaluation of QPD-1's detection limit and range for hPD-L1.
Main Results:
- QPD-1 successfully detected hPD-L1, utilizing the quenching ability of hPD-1 on its N-terminal label.
- The probe demonstrated a limit of detection of 10 nM and a detectable range of 10 nM to 1000 nM.
- QPD-1 proved to be a convenient tool for rapid hPD-L1 detection.
Conclusions:
- Quenched hPD-1 (QPD-1) is an effective fluorescent probe for detecting hPD-L1.
- QPD-1 can be used to screen for hPD-L1-overexpressing tumor cells, potentially guiding cancer immunotherapy decisions.
- This probe offers a valuable tool for advancing personalized cancer treatment strategies.
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