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A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
16:10

A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins

Published on: March 22, 2012

Intraflagellar transport is required for polarized recycling of the TCR/CD3 complex to the immune synapse

Francesca Finetti1, Silvia Rossi Paccani, Maria Giovanna Riparbelli

  • 1Department of Evolutionary Biology, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy.

Nature Cell Biology
|October 27, 2009
PubMed

Insights

Intraflagellar transport (IFT) proteins, like IFT20, regulate immune synapse assembly in T cells. This study reveals IFT20

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Biology

Background:

  • Primary cilia, sensory organelles in eukaryotic cells, are assembled via intraflagellar transport (IFT).
  • IFT involves protein complexes and molecular motors, crucial for ciliary structure and function.
  • Lymphoid and myeloid cells, typically lacking primary cilia, also express IFT proteins.

Purpose of the Study:

  • To investigate the role of IFT proteins in T-lymphocytes, particularly in the context of immune synapse formation.
  • To determine if IFT20 has functions beyond ciliogenesis in cells lacking primary cilia.
  • To explore the involvement of IFT in membrane trafficking and immune signaling.

Main Methods:

  • Immunofluorescence microscopy to observe IFT20 localization in T-lymphocytes.
  • Analysis of IFT20's role in immune synapse formation using antigen-specific conjugates.
  • Knockdown of IFT20 to assess its impact on T-cell receptor/CD3 (TCR/CD3) clustering and signaling.
  • Co-immunoprecipitation to study complex formation between IFT components and TCR.

Main Results:

  • IFT20 localizes to the microtubule organizing centre (MTOC), Golgi, and post-Golgi compartments in T-lymphocytes.
  • IFT20 translocates to the immune synapse upon T-cell activation.
  • IFT20 knockdown impairs TCR/CD3 clustering and signaling due to defective polarized recycling.
  • IFT20 is essential for the assembly of a complex involving IFT57, IFT88, and the TCR.

Conclusions:

  • IFT20 is identified as a novel regulator of immune synapse assembly in T cells.
  • This study provides the first evidence for IFT's role in membrane trafficking in cells without primary cilia.
  • The findings broaden the understanding of IFT function beyond its established role in ciliogenesis.

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