Related Experiment Video
Updated: Jul 10, 2026
16:10
A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
Published on: March 22, 2012
TCRζ-driven pre-signaling organization of Lck in Rab11⁺ endosomes shapes TCR activation
Konstantina Karpouzou1, Nikolaos Koutras1, Ioannis Tyritidis1
1Department of Biochemistry, School of Medicine, University of Patras, Patras, Greece.
Cellular & Molecular Biology Letters
|July 9, 2026
Summary
Vesicular T cell receptor (TCR) signaling components, like Lck and the zeta chain, form pre-assembled platforms. This coordinated trafficking enhances T cell activation sensitivity and persistence, with implications for immunotherapy.
Area of Science:
- Immunology
- Cell Biology
- Molecular Signaling
Background:
- T cell activation requires precise T cell receptor (TCR) signaling.
- Vesicular trafficking coordinates signaling molecule delivery at the immunological synapse.
- Endosomal pools of Lck and TCR zeta chain are linked to TCR signaling, but their trafficking is unclear.
Purpose of the Study:
- To investigate the mechanisms regulating and coordinating the trafficking routes of endosomal Lck and TCR zeta chain.
- To understand the role of vesicular trafficking in T cell receptor signaling competence.
Main Methods:
- Simultaneous tracking of endogenous Lck, zeta chain, and TCR endosomal localization.
- Utilized genetic modifications, confocal microscopy, and quantitative phospho-flow analysis.
- Biochemical assays and unpaired Student's t-tests for data analysis.
Main Results:
- Identified a novel plasma membrane-resident zeta chain pool independent of the TCR complex.
- This "standalone" zeta orchestrates Lck and CD45 mobilization into Rab11-positive compartments.
- Pre-assembled, signaling-primed platforms form, accommodating phosphorylated zeta and ZAP-70, dependent on endosomal Lck.
Conclusions:
- Coordinated trafficking of vesicular zeta and Lck pools is crucial for TCR activation.
- Vesicular pre-primed assemblies act as a reservoir, sustaining TCR signaling.
- Reveals a TCR-uncoupled zeta population seeding endosomal signaling platforms, advancing T cell activation models and offering immunotherapy insights.
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