Cell-based surface plasmon resonance approach for monitoring the inhibitory effect of Evasin-3 on Interleukin-8

Surface plasmon resonance (SPR) is a widely utilized technique for measuring the kinetics of molecular interactions. However, in dynamic living systems, the kinetics of target-ligand interactions may differ. Additionally, most cellular assays rely on end-point measurements, lacking the ability to monitor cellular interactions in real-time. In this study, a real-time cell-based SPR method was developed to investigate the inhibitory effect of small protein evasin-3 on the interaction between G protein-coupled receptors (GPCRs) and chemokine interleukin-8 (CXCL8). The interaction between CXCL8 and evasin-3 was first measured via a traditional SPR kinetic study. Their interaction was then confirmed and characterized using mass spectrometry, providing detailed insights into the complex formation of these two proteins. Endothelial EA.hy926 cells were immobilized on the SPR gold sensor, and real-time SPR response signals were monitored during stimulation with CXCL8, evasin-3 and their mixture. The results demonstrated the inhibitory effect of evasin-3 on the interaction between CXCL8 and GPCRs on EA.hy926 cells. This cell-based SPR method provides a valuable, physiologically relevant approach for studying inhibitory effects in living cells, presenting an effective alternative for analyzing complex molecular interactions.