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Updated: May 15, 2026
A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
Published on: March 22, 2012
Super-resolution characterization of TCR-dependent signaling clusters
Eilon Sherman1, Valarie Barr, Lawrence E Samelson
1Laboratory of Cellular and Molecular Biology, CCR, NCI, NIH, Bethesda, MD 20892-4256, USA. samelsonl@helix.nih.gov
Insights
Immune cell activation relies on signaling microclusters formed by T-cell receptors (TCRs). Advanced microscopy reveals dynamic nanostructures within these clusters, offering new insights into T cell function.
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- Immune cell activation is initiated by multi-molecular signaling complexes.
- These complexes form microclusters at the plasma membrane of T cells upon T-cell receptor (TCR) engagement.
- The precise molecular composition, structure, formation, and function of these microclusters remain incompletely understood.
Purpose of the Study:
- To investigate the molecular content, fine structure, formation mechanisms, and function of signaling microclusters.
- To leverage recent advancements in super-resolution microscopy for studying these structures at the single-molecule level.
- To elucidate the role of novel nanostructures within signaling clusters in T cell activation.
Main Methods:
- Utilizing super-resolution microscopy techniques with resolution down to approximately 20 nm.
- Analyzing signaling microclusters at the plasma membrane of intact T cells.
- Combining advanced microscopy with established techniques.
Main Results:
- Characterized size distributions of signaling clusters on the plasma membrane.
- Provided insights into the formation mechanisms governing microcluster assembly.
- Identified dynamic and functional nanostructures within signaling clusters.
Conclusions:
- Super-resolution microscopy is crucial for understanding signaling microclusters at the single-molecule level.
- Novel nanostructures within signaling clusters play a role in T cell activation.
- Further research combining methodologies will illuminate the nature and function of these critical T cell signaling hubs.
Abstract:
Multi-molecular signaling complexes drive the earliest events of immune cell activation via immunoreceptors with unexplained specificity and speed. Fluorescence microscopy has shown that these complexes form microclusters at the plasma membrane of activated T cells upon engagement of their antigen receptors (TCRs). Although crucial for cell function, much remains to be learned about the molecular content, fine structure, formation mechanisms, and function of these microclusters. Recent advancements in super-resolution microscopy have enabled the study of signaling microclusters at the single molecule level with resolution down to approximately 20 nm. These techniques have now helped to characterize the size distributions of signaling clusters at the plasma membrane of intact cells and to shed light on the formation mechanisms that govern their assembly. Surprisingly, dynamic and functional nanostructures have been identified within the signaling clusters. We expect that these novel methodologies, combined with older techniques, will shed new light on the nature of signaling clusters and their critical role in T-cell activation.
