Related Experiment Video

Updated: Jul 16, 2026

Visualizing the Early Stages of Phagocytosis
08:04

Visualizing the Early Stages of Phagocytosis

Published on: February 3, 2017

Biogenesis of Afipia-containing phagosomes in non-professional phagocytes

Christian Schueller1, Bianca Schneider, Volkhard A J Kempf

  • 1Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Strasse 61a, 53121 Bonn, Germany.

Microbes and Infection
|February 20, 2007
PubMed

Insights

Afipia felis efficiently invades various mammalian cells, utilizing actin for entry. This bacterium

Area of Science:

  • Microbiology
  • Cell Biology
  • Infectious Diseases

Background:

  • Afipia felis is a Gram-negative bacterium causing cat scratch disease (CSD).
  • Its interaction with non-phagocytic host cells is not well understood.
  • Afipia species are also implicated as amoeba pathogens.

Purpose of the Study:

  • To investigate the ability of Afipia felis to invade non-professional phagocytic mammalian cells.
  • To characterize the cellular mechanisms and intracellular trafficking of A. felis entry.
  • To compare the intracellular fate of A. felis in different cell types.

Main Methods:

  • Co-incubation of A. felis with various mammalian cell lines (CHO, EA.hy926, HeLa, INT407, HMEC-1, HUVEC, L929).
  • Assessment of bacterial uptake and dependence on host cell cytoskeleton (actin, microtubules).
  • Immunofluorescence microscopy to track bacterial location and phagosome maturation markers (EEA1, LAMP1, proton-pumping ATPase).

Main Results:

  • A. felis efficiently invaded multiple non-professional phagocytes, unlike other Afipia species.
  • Bacterial entry was dependent on the actin cytoskeleton.
  • A. felis resided in LAMP1-positive phagosomes in non-professional phagocytes, indicating phagolysosome maturation, but in a non-canonical compartment in macrophages.

Conclusions:

  • Afipia felis demonstrates efficient invasion of diverse non-professional phagocytes.
  • Intracellular trafficking of A. felis differs significantly between macrophages and non-professional phagocytes.
  • These findings provide insights into the pathogenesis of A. felis and CSD.

More Related Videos

"Phagosome Closure Assay" to Visualize Phagosome Formation in Three Dimensions Using Total Internal Reflection Fluorescent Microscopy (TIRFM)10:07

"Phagosome Closure Assay" to Visualize Phagosome Formation in Three Dimensions Using Total Internal Reflection Fluorescent Microscopy (TIRFM)

Published on: August 26, 2016

Study of Phagolysosome Biogenesis in Live Macrophages08:06

Study of Phagolysosome Biogenesis in Live Macrophages

Published on: March 10, 2014

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.
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...
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). Many immune system cells, including...
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...
Autophagy01:27

Autophagy

Autophagy is a self-digesting process by which a cell protects itself from threats both within and outside the cell, ranging from abnormal proteins to invading bacteria. In this process, obsolete components of the cell and invading microbes are degraded by hydrolytic enzymes active in an acidic environment of the lysosomal lumen.
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
Delivery Pathways to the Lysosome01:36

Delivery Pathways to the Lysosome

Eukaryotic cells use different mechanisms to eliminate toxic waste obsolete and worn-out substances. Lysosomes play a pivotal role in this, and hence, these substances are carried to the lysosome from other parts of the cell and extracellular space through different pathways. The most elaborately studied pathways to the lysosome are the endocytic pathways.
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...