Related Experiment Video

Updated: Aug 30, 2026

Experimental Analysis of Apoptotic Thymocyte Engulfment by Macrophages
06:47

Experimental Analysis of Apoptotic Thymocyte Engulfment by Macrophages

Published on: May 24, 2019

Phagocytosis induces superoxide formation and apoptosis in macrophages

Jae-Bong Park1

  • 1Department of Biochemistry, College of Medicine, Hallym University, Ockchon 1, Kangwon-do 200-702, Korea. jbpark@hallym.ac.kr

Experimental & Molecular Medicine
|December 4, 2003
PubMed

Insights

Phagocytosis by immune cells, crucial for innate immunity, involves actin assembly and Rho GTPases. This process triggers an oxidative burst via NADPH oxidase, potentially leading to leukocyte apoptosis.

Area of Science:

  • Immunology
  • Cell Biology
  • Biochemistry

Background:

  • Phagocytosis is a key innate immune mechanism for clearing pathogens and cellular debris.
  • This process relies on receptor-ligand interactions and cytoskeletal rearrangements, including actin assembly.
  • Rho GTPases (RhoA, Cdc42, Rac1) are essential regulators of phagocytic events.

Purpose of the Study:

  • To elucidate the role of Rho GTPases in phagocytosis.
  • To describe the formation and function of the NADPH oxidase complex during phagocytosis.
  • To investigate the link between phagocytosis-induced oxidative burst and leukocyte apoptosis.

Main Methods:

  • Studied phagocytosis mechanisms in inflammatory cells.
  • Investigated the involvement of Rho GTPases in actin assembly and phagosome formation.
  • Analyzed the assembly and activation of the NADPH oxidase complex.
  • Assessed oxidative burst and apoptosis markers like cytochrome c and caspase-3.

Main Results:

  • Rho GTPases are critical for actin assembly, pseudopod extension, and phagosome closure during phagocytosis.
  • Phagocytosis triggers an oxidative burst mediated by the assembled NADPH oxidase complex in leukocytes.
  • Leukocyte apoptosis is induced by IgG- and complement-opsonized particle uptake, potentially via oxidative burst, cytochrome c release, and caspase-3 activation.

Conclusions:

  • Phagocytosis is a complex process regulated by Rho GTPases and culminating in an oxidative burst.
  • The NADPH oxidase complex plays a central role in generating reactive oxygen species during phagocytosis.
  • Phagocytosis-induced oxidative stress contributes to leukocyte apoptosis, highlighting a mechanism of immune cell regulation.

More Related Videos

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Published on: December 27, 2016

Quantification of Efferocytosis by Single-cell Fluorescence Microscopy06:15

Quantification of Efferocytosis by Single-cell Fluorescence Microscopy

Published on: August 18, 2018

Related Concept Videos

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.
Autophagic Cell Death01:18

Autophagic Cell Death

Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
Immune Surveillance by NK Cells and Phagocytes01:25

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...
Phagocytosis00:41

Phagocytosis

Cells pull particles inward and engulf them in spherical vesicles in an energy-requiring process called endocytosis. Phagocytosis (“cellular eating”) is one of three major types of endocytosis. Cells use phagocytosis to take in large objects—such as other cells (or their debris), bacteria, and even viruses.The objective of phagocytosis is often destruction. Cells use phagocytosis to eliminate unwelcome visitors, like pathogens (e.g., viruses and bacteria). It is perhaps unsurprising, that many...
Cellular Injury V: Apoptosis and Autophagy01:22

Cellular Injury V: Apoptosis and Autophagy

Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...
Apoptosis01:30

Apoptosis

Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size reduction of the tissue.