Application Notes
Quantitative Live-Cell Imaging to Analyze Immune Cell Secretion Activity and Gene Expression
March 2025
Single-cell RNA sequencing (scRNA-seq) has revolutionized our understanding of cellular heterogeneity by identifying distinct cell types and states at the molecular level. However, its destructive nature limits insights into dynamic cellular processes. While conventional live-cell imaging can visualize cell morphology, motility, and the dynamics of a few pre- labeled molecules, it has limitations in capturing the dynamic functions of intact cells.
To overcome these limitations, researchers led by Dr. Yoshitaka Shirasaki (Research Center for Advanced Science and Technology, The University of Tokyo) and Dr. Mai Yamagishi (Live Cell Diagnosis, Ltd.) developed Live Cell Imaging of Secretion Activity (LCI-S), which combines Total Internal Reflection Fluorescence Microscopy (TIRFM) with FluoroSpot technology to enable real-time visualization and quantification of secreted proteins at the single-cell level. They further developed Time-Dependent Cell-State Selection (TDCSS), enabling selective isolation of cells in specific secretory states detected by LCI-S for subsequent scRNA-seq analysis. Using the Nikon Perfect Focus System (PFS), they achieved stable long-term imaging over five days, allowing them to capture rare cellular events and identify previously uncharacterized gene expression profiles associated with immune cell activation. This application note highlights their findings on the dynamic secretory activities and rapid gene expression changes upon activation in immune cells achieved with LCI-S and TDCSS. The collaborative research effort involves the laboratories of Dr. Shirasaki and Dr. Yamagishi, Dr. Kazuyo Moro from Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Dr. Koichi Fukunaga from Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine and Dr. Sotaro Uemura from Department of Biological Sciences, Graduate School of Science, The University of Tokyo.
Keywords: Live-cell imaging, Dynamic analysis, Secretory activity, Single-cell RNA sequencing, Immune cells