Related Experiment Video

Updated: May 28, 2026

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
11:32

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

Pneumococcus uses COMMD2 to alter host cellular immunity

Michael G Connor1, Lisa Sanchez2, Christine Chevalier3

  • 1Chromatin and Infection Laboratory, Institut Pasteur, Université Paris Cité, Paris, France. mconnor@pasteur.fr.

Nature Communications
|May 26, 2026
PubMed

Insights

Streptococcus pneumoniae uses COMMD2 to degrade the NF-κB (nuclear factor kappa B) protein p65, repressing host immunity during infection. This mechanism explains how pathogenic pneumococcus evades the immune response.

Area of Science:

  • Microbiology
  • Immunology
  • Cellular Biology

Background:

  • NF-κB (nuclear factor kappa B) signaling is crucial for cellular immunity against microbes.
  • Bacteria frequently target the NF-κB pathway during pathogenesis.
  • The role of NF-κB in epithelial responses to Streptococcus pneumoniae, from commensal to pathogenic, remains unclear.

Purpose of the Study:

  • To investigate how Streptococcus pneumoniae modulates NF-κB signaling in epithelial cells.
  • To compare the NF-κB interactome of a commensal-like strain (6B ST90) versus an invasive strain (TIGR4).
  • To elucidate the mechanism by which an invasive pneumococcal strain represses host inflammatory responses.

Main Methods:

  • Comparative mass spectrometry of the p65 interactome.
  • Analysis of host-pathogen interactions between Streptococcus pneumoniae strains and epithelial cells.

Main Results:

  • Invasive TIGR4 strain challenge induced the interaction of COMMD2 with p65 and p62.
  • This complex mediates the export and subsequent degradation of p65.
  • COMMD2 is essential for modulating host cellular immunity during pneumococcal infection.

Conclusions:

  • A novel bacterial pathogenesis mechanism involving COMMD2-mediated degradation of p65 was identified.
  • This mechanism serves to repress the host inflammatory response during Streptococcus pneumoniae infection.
  • The study presents a paradigm for divergent NF-κB responses to pneumococcal strains.

More Related Videos

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae09:12

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Published on: January 17, 2014

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness12:21

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness

Published on: September 28, 2022

Related Concept Videos

Pneumonia II: Pathophysiology01:29

Pneumonia II: Pathophysiology

The pathophysiology of pneumonia involves the following steps:
Cell-mediated Immune Responses01:40

Cell-mediated Immune Responses

Overview
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...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Pneumonia I: Introduction01:29

Pneumonia I: Introduction

Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...
Pneumonia I: Introduction01:30

Pneumonia I: Introduction

Pneumonia is an acute respiratory infection that targets the lungs, specifically the alveoli. These tiny air sacs, essential for oxygen exchange, become engorged with pus and fluid, severely hindering breathing, decreasing oxygen absorption, and causing significant pain and discomfort during respiration.
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...