Related Experiment Video

Updated: Nov 7, 2025

Quantification of Cytosolic vs. Vacuolar Salmonella in Primary Macrophages by Differential Permeabilization
09:25

Quantification of Cytosolic vs. Vacuolar Salmonella in Primary Macrophages by Differential Permeabilization

Published on: July 28, 2015

11.1K

PRAK Promotes the Pathogen Clearance by Macrophage Through Regulating Autophagy and Inflammasome Activation

Ligu Mi1,2, Yan Wang1, Hui Xu3

  • 1Department of Immunology, School of Basic Medical Sciences, National Health Commission (NHC) Key Laboratory of Medical Immunology, Peking University, Beijing, China.

Frontiers in Immunology
|May 3, 2021
PubMed

Insights

The p38 regulated/activated protein kinase (PRAK) is crucial for macrophage function in fighting infections. PRAK deficiency impairs bacterial clearance and increases susceptibility to pathogens like Listeria monocytogenes.

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Biology

Background:

  • p38 regulated/activated protein kinase (PRAK) is a downstream kinase of p38MAPK.
  • The role of PRAK in macrophage function remains largely unexplored.

Purpose of the Study:

  • To investigate the function of PRAK in macrophages.
  • To determine PRAK's role in host defense against intracellular pathogens.

Main Methods:

  • Generated myeloid-specific Prak-deficient mice.
  • Assessed macrophage populations, phenotype, and function.
  • Infected mice with Listeria monocytogenes and evaluated host survival, bacterial load, and cytokine levels.
  • Investigated ROS production, inflammasome activation, and autophagy in Prak-deficient macrophages.

Main Results:

  • Myeloid-specific Prak deletion reduced peritoneal macrophages (F4/80+CD11b+) with decreased MHC-II and CD80 expression.
  • Prak-deficient mice exhibited increased mortality, higher bacterial burden, and elevated proinflammatory cytokines after L. monocytogenes infection.
  • Prak-deficient macrophages showed impaired bactericidal activity, defective ROS production, inflammasome activation, and autophagy.

Conclusions:

  • PRAK is essential for macrophage-mediated clearance of intracellular pathogens.
  • PRAK influences multiple macrophage functions, including phagocytosis, bacterial killing, ROS generation, inflammasome activation, and autophagy.
  • PRAK plays a critical role in the innate immune response to bacterial infection.
Keywords:
autophagymacrophagep38-regulated/activated protein kinasepathogenphagocytosis

More Related Videos

Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages06:52

Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages

Published on: May 21, 2018

11.0K
High Throughput Fluorometric Technique for Assessment of Macrophage Phagocytosis and Actin Polymerization09:22

High Throughput Fluorometric Technique for Assessment of Macrophage Phagocytosis and Actin Polymerization

Published on: November 27, 2014

14.9K

Related Concept Videos

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...
6.8K
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,...
5.2K
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...
8.3K
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...
4.2K
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
1.7K
Cells of the Innate Immune Response01:28

Cells of the Innate Immune Response

The innate immune response is an immediate and non-specific response against pathogens, acting swiftly to prevent the spread of infections. The primary cells involved in this response are phagocytes and natural killer (NK) cells.
Phagocytes
Phagocytes police the peripheral tissues by removing cellular debris and responding to the invasion of foreign substances or pathogens. Many phagocytes attack and remove microorganisms even before lymphocytes detect them. The human body has two general...
7.4K