Related Experiment Video

Updated: Sep 27, 2026

Assessing Microglial Phagocytosis of Myelin Debris in vitro Under Repeated Magnetic Stimulation
08:34

Assessing Microglial Phagocytosis of Myelin Debris in vitro Under Repeated Magnetic Stimulation

Published on: June 17, 2025

Complement-receptor-3 and scavenger-receptor-AI/II mediated myelin phagocytosis in microglia and macrophages

Fanny Reichert1, Shlomo Rotshenker

  • 1Department of Anatomy & Cell Biology, Hebrew University-Hadassah Medical School and the Eric Roland Center for Neurodegenerative Diseases, Jerusalem 91120, Israel.

Neurobiology of Disease
|March 1, 2003
PubMed

Insights

Microglia and macrophages use complement receptor-3 (CR3/MAC-1) and scavenger receptor AI/II (SRAI/II) to engulf myelin. Antibodies targeting CR3/MAC-1 significantly modulated this phagocytosis, revealing new regulatory mechanisms.

Area of Science:

  • Immunology
  • Neuroscience
  • Cell Biology

Background:

  • Microglia and macrophages are key immune cells in the central nervous system.
  • These cells express complement receptor-3 (CR3/MAC-1) and scavenger receptor AI/II (SRAI/II), which are involved in phagocytosis.
  • Myelin phagocytosis by these cells is crucial for tissue homeostasis and repair.

Purpose of the Study:

  • To investigate the role of CR3/MAC-1 in myelin phagocytosis by microglia and macrophages.
  • To determine how complement and specific antibodies modulate CR3/MAC-1-mediated myelin phagocytosis.
  • To compare the contribution of CR3/MAC-1 and SRAI/II to myelin phagocytosis.

Main Methods:

  • Utilized primary microglia and macrophages.
  • Employed complement and anti-CR3/MAC-1 monoclonal antibodies (mAbs) to modulate phagocytosis.
  • Quantified myelin phagocytosis using various anti-CR3/MAC-1 mAbs, including M1/70, 5C6, M18/2, and Game-46.
  • Assessed the combined effects of different mAbs and complement on phagocytic activity.

Main Results:

  • Complement significantly augmented CR3/MAC-1 mediated myelin phagocytosis.
  • Anti-alpha(M) mAbs (M1/70, 5C6) inhibited phagocytosis, while anti-beta(2) mAb (M18/2) augmented it.
  • Complement modulated the effects of these antibodies.
  • Combinations of anti-beta(2) mAbs showed potentiated augmentation, while combinations with anti-alpha(M) mAbs resulted in inhibition.
  • CR3/MAC-1 contributed two- to threefold more to myelin phagocytosis than SRAI/II when functioning together.

Conclusions:

  • CR3/MAC-1 plays a significant role in myelin phagocytosis by microglia and macrophages.
  • Complement and specific anti-CR3/MAC-1 antibodies can finely tune this phagocytic process.
  • These findings suggest potential therapeutic strategies targeting CR3/MAC-1 for myelin-related disorders.

More Related Videos

In vitro Quantitative Imaging Assay for Phagocytosis of Dead Neuroblastoma Cells by iPSC-Macrophages09:48

In vitro Quantitative Imaging Assay for Phagocytosis of Dead Neuroblastoma Cells by iPSC-Macrophages

Published on: February 14, 2021

In Vitro Phagocytosis of Myelin Debris by Bone Marrow-Derived Macrophages12:27

In Vitro Phagocytosis of Myelin Debris by Bone Marrow-Derived Macrophages

Published on: December 30, 2017

Related Concept Videos

Immune Surveillance by NK Cells and Phagocytes01:27

Immune Surveillance by NK Cells and Phagocytes

Immune surveillance is an integral part of the innate immune system, involving the continuous monitoring of peripheral tissues to detect and respond to pathogens, infected cells, or cancerous cells. This surveillance is conducted primarily by natural killer (NK) cells and phagocytes, which employ distinct but complementary mechanisms to identify and eliminate threats.
Natural Killer Cells: The Fast Responders
NK cells are large granular lymphocytes found in the blood and lymphatic system. These...
Phagocytosis of Apoptotic Cells01:17

Phagocytosis of Apoptotic Cells

Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or  immature dendritic cells. Non-professional phagocytes such as  epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes. 
Normal cells contain receptors that prevent them from being recognized by phagocytes.