Identifying PD-1/PD-L1 Inhibitors with Surface Plasmon Resonance Technology

I work in drug discovery, finding new cancer immune checkpoint inhibitors, like PD-1, PD-L1. My key question is how can we design a high throughput screen platform to speed this up? In recent years, biological drugs targeting PD-1, PD-L1 have made significant progress. While small molecule drugs are still in the early stages of development, we aim to develop small molecule drugs targeting PD-1, PD-L1.

Homogeneous time resolved fluorescence, HTIF, and the af-ah-ly-zer are two technologies with applications in PD-1, PD-L1 inhibitor screening. The solubility of small molecules and the buffer mismatch are the primary challenges in the current experiment.

We discovered that SPR can be developed not only for binding affinity measurements, but also as a screening platform for PD-1, PD-L1 inhibitors.

[Instructor] To begin, switch on the surface plasmin resonance or SPR instrument. Click on open or new wizard template and choose immobilization to set the immobilization method. Set the chip type to CM-5. Set the Amin method and the flow cells per cycle to one. Then check immobilize flow cell one and flow cell two as SA-40 micrograms per milliliter. Select SA biotin capture as the immobilization method. Set flow cell one for blank immobilization. For flow cell two, aim for an immobilized level with 10 micrograms per milliliter, PD-1, as the ligand, and a target of 4,000 response units. Then check prime before running. Place two bay containing the buffer inlets into the HBSEP positive running buffer solution. Eject the maintenance sensor chip and insert the CM-5 chip. Reopen the immobilization method. Then insert reagent rack two and verify reagent positions. Run the method for the estimated duration. Place two bay into the HBSEP positive running buffer solution. Eject the maintenance sensor chip, and insert the SA chip. After reopening the immobilization method, insert reagent rack two and verify reagent positions. Run the method for the estimated duration. For the validation of PD-1, PD-L1 interactions, under general settings, set the data collection rate at 10 hertz. Detection is multi. Sample compartment temperature to 25 degrees celsius and concentration unit as micromolar. Under assay steps, set conditioning replicates to 10 times. Start up to kinetics with replicates at 10 times. Sample to kinetics with one replicate and temperature at 25 degrees Celsius. Then set the contact time to 60 seconds, dissociation time to 60 seconds, and flow rate to 30 microliters per minute. Under method variables, set property as a variable and select sample solution. Under evaluation variables, select evaluation purpose as kinetics affinity and select the predefined variables as concentration and MW. Set up run and select the flow path two to one and four to three. Input PD-L1 concentrations of zero micromolar, 0.037 micromolar, 0.111 micromolar, and 0.333 micromolar with a molecular weight of 51,300 Daltons. Prepare 200 milliliters of HBSEP positive running buffer solution and dilution of PD-L1 dilution in the running buffer. Place all reagents in the respective positions on the layout and run for the estimated duration. For the blockade assay, with small molecule inhibitor, use the same settings and flow rates as done for the validation testing. After setting up the run and choosing the flow paths, input the sample PD-L1 solution and the dilute BMS 1166 solutions. Assign well positions in the reagent rack two layout, as given. Then dissolve five milligrams of BMS 1166 in 77.99 microliters of DMSO to prepare a 100 millimolar stock solution. Arrange all reagents as given. The target response unit of 2000 response units was nearly achieved for streptavidin protein immobilization on flow cell one and flow cell two. Flow cell one showed a final response of 1902.3 response units, while flow cell two showed 1900.7 response units. The blank cell on flow cell one had a low response unit of minus 161, while flow cell two achieved the target of 4,000 response units with a final response of 3698.5. Among the tested glycine pH conditions, glycine pH 2.0 was identified as the most optimal for regeneration with a stable baseline response, indicating minimal PD-1 protein loss and successful removal of PD-L1. The binding interaction of PD-L1 at varying concentrations with PD-1 was quantified, yielding a measurable response. The blockade effect of PD-1, PD-L1 binding interaction was observed with BMS 1166 dilution between zero to 3.125 micromolar. The binding response unit decreased proportionally as the concentration of BMS 1166 increased.