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Updated: Sep 27, 2025
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Visualizing the Actin and Microtubule Cytoskeletons at the B-cell Immune Synapse Using Stimulated Emission Depletion STED Microscopy
Published on: April 9, 2018
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A B-cell actomyosin arc network couples integrin co-stimulation to mechanical force-dependent immune synapse
Jia C Wang1, Yang-In Yim1, Xufeng Wu2
1Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, United States.
Elife
|April 11, 2022
Summary
Integrin LFA-1 interactions promote B-cell immune synapse formation by creating an actomyosin network. This network, driven by myosin, is crucial for antigen centralization and B-cell receptor signaling.
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- B-cell activation and immune synapse (IS) formation are actin-dependent.
- Integrin LFA-1 binding to ICAM-1 enhances IS formation, especially with limited antigen.
- The specific role of the actin cytoskeleton in integrin-dependent IS formation is unclear.
Purpose of the Study:
- To investigate the role of the actin cytoskeleton in integrin-dependent immune synapse formation in B cells.
- To elucidate the mechanism by which LFA-1 co-stimulation promotes B-cell activation and IS formation.
Main Methods:
- Super-resolution imaging of primary mouse B cells.
- Investigating the formation and dynamics of actomyosin networks.
- Inhibiting myosin function to assess its impact on synapse formation and signaling.
Main Results:
- LFA-1:ICAM-1 interactions induce an actomyosin network that dominates the B-cell IS.
- This network is formed by mDia1 and organized into contractile arcs by myosin 2A.
- Inhibiting myosin impairs IS formation, antigen centralization, BCR signaling, and protein distribution.
Conclusions:
- A contractile actomyosin arc network is essential for LFA-1 co-stimulation to promote B-cell activation and IS formation.
- The actomyosin network actively drives antigen cluster centralization within the IS.
- These findings reveal a novel mechanism linking integrin signaling to cytoskeletal dynamics in B cells.
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