Related Experiment Video

Updated: Jul 9, 2026

Visualizing the Actin and Microtubule Cytoskeletons at the B-cell Immune Synapse Using Stimulated Emission Depletion (STED) Microscopy
11:00

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CD19 is essential for B cell activation by promoting B cell receptor-antigen microcluster formation in response to

David Depoil1, Sebastian Fleire, Bebhinn L Treanor

  • 1Lymphocyte Interaction Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.

Nature Immunology
|December 7, 2007
PubMed

Insights

The B cell antigen receptor (BCR) signalosome

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Biology

Background:

  • B cell activation is crucial for adaptive immunity.
  • Early signaling events dictate B cell responses.

Purpose of the Study:

  • To elucidate the spatiotemporal organization of the BCR signalosome during early B cell activation.
  • To define the role of CD19 in BCR-dependent signaling.

Main Methods:

  • High-resolution imaging of mouse B cells.
  • Analysis of receptor and signaling molecule dynamics.
  • Genetic deficiency models (CD19-deficient B cells).

Main Results:

  • BCR microclusters form upon ligand stimulation, recruiting Syk and associating with CD19.
  • CD19-deficient B cells show impaired signaling initiation, effector accumulation, and cell spreading.
  • Microcluster formation was reduced in CD19-deficient B cells.

Conclusions:

  • CD19 plays an essential, costimulatory molecule CD21-independent role in amplifying early B cell activation.
  • The study defines the dynamics of BCR signalosome assembly and highlights CD19's critical function.

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