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Updated: Jun 27, 2025

Direct Observation of Phagocytosis and NET-formation by Neutrophils in Infected Lungs using 2-photon Microscopy
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Nude blebs expose cells to phagocytes

Annalisa M VanHook1

  • 1Science Signaling, AAAS, Washington, DC 20005, USA.

Science Signaling
|April 30, 2024
PubMed

Insights

Macrophages recognize dying cells when their outer layer, the glycocalyx, is shed via membrane blebbing. This process is crucial for efficient cellular debris clearance.

Area of Science:

  • Cell biology
  • Immunology
  • Apoptosis research

Background:

  • The glycocalyx is a crucial cell surface layer involved in cell-cell interactions and protection.
  • Macrophages are key immune cells responsible for clearing apoptotic cells.
  • Mechanisms by which macrophages recognize and engulf dying cells are not fully understood.

Purpose of the Study:

  • To investigate the role of the glycocalyx and membrane blebbing in macrophage recognition of apoptotic cells.

Main Methods:

  • Utilized live-cell imaging to observe macrophage-apoptotic cell interactions.
  • Employing fluorescent microscopy to visualize glycocalyx and membrane dynamics.
  • Biochemical assays to assess phagocytosis efficiency.

Main Results:

  • Demonstrated that displacement of the glycocalyx on apoptotic cells is a prerequisite for recognition by macrophages.
  • Observed that membrane blebbing directly leads to glycocalyx shedding.
  • Showed that glycocalyx removal enhances the rate of apoptotic cell engulfment.

Conclusions:

  • Glycocalyx shedding via membrane blebbing is a critical signal for macrophage-mediated efferocytosis.
  • This finding provides new insights into the molecular mechanisms of apoptotic cell clearance.
  • Targeting glycocalyx dynamics could offer therapeutic strategies for inflammatory diseases.

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