Microfluidic devices for characterizing the agonist of formyl peptide receptor in RBL-FPR cells

The human formyl peptide receptor (FPR) plays an important role in inflammation and immunity. Finding of specific agonists and antagonists of FPR may provide potential therapeutic agents for FPR related disorders. The binding of agonist by FPR induces a cascade of G protein-mediated signaling events leading to neutrophil chemotaxis, intracellualr calcium mobilization, FPR ligand uptake and so on. This work proposed a microfluidic-based method to characterize FPR-related cellular events in response to small peptides, N-formyl-Met-Leu-Phe (fMLF), in rat basophilic leukemia cell line RBL-2H3 expressing human FPR (RBL-FPR). The results showed that fMLF triggered chemotaxis, calcium mobilization and FPR ligand uptake in RBL-FPR cells, indicating the potential role of FPR agonist. The chemotaxis index and the calcium mobilization intensity increased but the time course of calcium mobilization decreased, as the rising of fMLF concentration. The basic agreement between the microfluidic results and the previous studies demonstrated good feasibility of the microfluidic method for characterization of FPR agonist. Microfluidic technology displays significant advantages over traditional methods in terms of sample consumption and assay time. It also facilitates experimental process and real-time observation of cellular responses at single cell resolution.