Related Experiment Video

Updated: Jun 21, 2026

Analysis of Microglia and Monocyte-derived Macrophages from the Central Nervous System by Flow Cytometry
10:43

Analysis of Microglia and Monocyte-derived Macrophages from the Central Nervous System by Flow Cytometry

Published on: June 22, 2017

Bacterial infection reshapes monocyte and macrophage ontogeny at the CNS borders

Vitka Gres1, Florens Lohrmann1,2, Vidmantė Fuchs3,4

  • 1Institute for Infection Prevention and Control, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany.

Science Immunology
|June 19, 2026
PubMed

Insights

This study reveals how monocytes infiltrate the brain during meningitis, replacing resident macrophages in the dura and differentiating into specialized cells that aid in immune defense and recovery. Understanding these processes is key to developing new treatments for CNS infections.

Area of Science:

  • Neuroimmunology
  • Infectious Diseases
  • Cellular Biology

Background:

  • Macrophages in the meninges are crucial for central nervous system (CNS) immune defense.
  • Their specific origins and functions during CNS infections are not well understood.

Purpose of the Study:

  • To investigate the origin and function of meningeal macrophages during experimental streptococcal meningoencephalitis in mice.
  • To elucidate the dynamic changes in monocyte recruitment and differentiation across CNS borders during infection.

Main Methods:

  • Intravenous model of streptococcal meningoencephalitis in mice.
  • Analysis of bacterial distribution, monocyte infiltration, and macrophage populations in the leptomeninges, dura, and parenchyma.
  • Tracking of monocyte origins and differentiation pathways.

Main Results:

  • Bacteria were predominantly found in the leptomeninges and dura, while monocyte infiltration correlated with disease severity.
  • Infection led to activation and loss of resident dural macrophages, replaced by inflammatory monocytes.
  • Dural monocytes shifted from a CCR2-independent source to peripheral bone marrow recruitment during infection.
  • Monocyte differentiation was altered, increasing monocyte-dendritic cell progenitor-derived monocytes with enhanced MHC class II expression.

Conclusions:

  • Monocyte recruitment and differentiation are dynamically remodeled across CNS borders during bacterial meningoencephalitis.
  • These findings highlight compartment-specific responses within the meninges and CNS parenchyma.
  • Understanding these cellular dynamics is crucial for developing targeted therapies for CNS infections.

More Related Videos

Isolation and Culture of Rodent Microglia to Promote a Dynamic Ramified Morphology in Serum-free Medium12:00

Isolation and Culture of Rodent Microglia to Promote a Dynamic Ramified Morphology in Serum-free Medium

Published on: March 9, 2018

Rapid and Refined CD11b Magnetic Isolation of Primary Microglia with Enhanced Purity and Versatility07:54

Rapid and Refined CD11b Magnetic Isolation of Primary Microglia with Enhanced Purity and Versatility

Published on: April 13, 2017

Related Concept Videos

Bacterial Meningitis II: Pathophysiology01:26

Bacterial Meningitis II: Pathophysiology

Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...
Differentiation of Common Myeloid Progenitor Cells01:15

Differentiation of Common Myeloid Progenitor Cells

Common myeloid progenitors (CMPs) are oligopotent cells that can differentiate into granulocytes and macrophages. Granulocytes and macrophages are essential for protecting the body against bacterial, viral, or fungal infections. They migrate from the bone marrow into the circulating blood to reach specific tissue sites where they differentiate and help in immune surveillance. However, they survive only for a few days and must be continuously made available to the organism to maintain a robust...
Neurogenesis and Regeneration of Nervous Tissue01:15

Neurogenesis and Regeneration of Nervous Tissue

In the CNS, neurogenesis, the birth of new neurons from stem cells, is limited to the hippocampus in adults. In other regions of the brain and spinal cord, neurogenesis is almost non-existent due to inhibitory influences from neuroglia, especially oligodendrocytes, and the absence of growth-stimulating cues. The myelin produced by oligodendrocytes in the CNS inhibits neuronal regeneration. Furthermore, astrocytes proliferate rapidly after neuronal damage, forming scar tissue that physically...
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...
Bacterial Meningitis01:24

Bacterial Meningitis

Bacterial meningitis is a severe infectious disease involving inflammation of the meninges, the protective membranes surrounding the brain and spinal cord. It occurs when pathogenic bacteria cross the blood–brain barrier and enter the cerebrospinal fluid. Common causative organisms include Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b, Listeria monocytogenes, and Escherichia coli K1. The exact route of entry varies by pathogen and host condition.Routes of Entry...
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...