Sign In

37.6 : 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. For example, red blood cells display CD47 receptors that block phagocytosis. Another marker, CD31, also known as platelet endothelial cell adhesion molecule-1, is expressed by normal cells, which prevents phagocyte attachment. During apoptosis, CD31 is not expressed, leading to phagocyte recognition and phagocytosis.

Apoptotic cells release 'find-me'signals such as lysophosphatidylcholine, sphingosine-1-phosphate, fractalkine, thrombospondin-1, ATP, and UTP to help phagocyte recognition. Once the phagocytes reach the location, the apoptotic cells display 'eat-me'signals, such as apoptotic cell-associated molecular patterns (ACAMP) and phosphatidylserine. When phagocytes attach to apoptotic cells, they release anti-inflammatory cytokines such as IL-10 and TGF-ꞵ, creating a non-inflammatory microenvironment. This prevents damage to neighboring cells. Once the apoptotic cells are internalized, they are broken down into nucleotides, amino acids, and sterols which are further recycled.

Tags
PhagocytosisApoptotic CellsMacrophagesDendritic CellsEpithelial CellsFibroblastsCD47CD31Find me SignalsEat me SignalsAnti inflammatory CytokinesIL 10TGF

From Chapter 37:

article

Now Playing

37.6 : Phagocytosis of Apoptotic Cells

Cell Death

2.9K Views

article

37.1 : Overview of Cell Death

Cell Death

5.1K Views

article

37.2 : Apoptosis

Cell Death

8.5K Views

article

37.3 : Caspases

Cell Death

10.9K Views

article

37.4 : The Extrinsic Apoptotic Pathway

Cell Death

5.0K Views

article

37.5 : The Intrinsic Apoptotic Pathway

Cell Death

5.1K Views

article

37.7 : Autophagic Cell Death

Cell Death

2.5K Views

article

37.8 : Necrosis

Cell Death

3.4K Views

JoVE Logo

Privacy

Terms of Use

Policies

Research

Education

ABOUT JoVE

Copyright © 2025 MyJoVE Corporation. All rights reserved