Related Experiment Video

Updated: Jun 20, 2026

Expression, Purification, and Antimicrobial Activity of S100A12
11:10

Expression, Purification, and Antimicrobial Activity of S100A12

Published on: May 13, 2017

Bacterial surface protein L binds and inactivates neutrophil proteins S100A8/A9

Bo Akerström1, Lars Björck

  • 1Department of Clinical Sciences, Division of Infection Medicine, Lund University, BMC, B14, Solvegatan 19, Lund SE-22184, Sweden. bo.akerstrom@med.lu.se

Journal of Immunology (Baltimore, Md. : 1950)
|September 16, 2009
PubMed

Insights

Finegoldia magna, an opportunistic pathogen, uses its surface protein L to evade immune defenses. Protein L binds both immunoglobulins and S100A8/A9 antibacterial proteins, protecting the bacteria from innate and adaptive immunity.

Area of Science:

  • Microbiology
  • Immunology
  • Bacterial Pathogenesis

Background:

  • Finegoldia magna is a commensal bacterium and opportunistic pathogen.
  • Certain F. magna isolates express protein L, which binds immunoglobulins (Igs) via Ig light chains.
  • S100A8/A9 are antibacterial proteins found in neutrophils and extracellularly during inflammation.

Purpose of the Study:

  • To investigate the interaction between F. magna protein L and S100A8/A9.
  • To determine if protein L influences bacterial susceptibility to S100A8/A9.

Main Methods:

  • Protein L domain analysis.
  • Co-immunoprecipitation assays.
  • Bacterial killing assays.

Main Results:

  • The N-terminal A domain of protein L binds S100A8/A9.
  • F. magna expressing protein L are protected against S100A8/A9-mediated killing.
  • Protein L binds Igs and S100A8/A9 independently.

Conclusions:

  • F. magna protein L actively manipulates both adaptive (Ig) and innate (S100A8/A9) immune mechanisms.
  • This interaction confers bacterial resistance to host defense proteins.

More Related Videos

Studying Interactions of Staphylococcus aureus with Neutrophils by Flow Cytometry and Time Lapse Microscopy10:40

Studying Interactions of Staphylococcus aureus with Neutrophils by Flow Cytometry and Time Lapse Microscopy

Published on: July 17, 2013

Purification of Human S100A12 and Its Ion-induced Oligomers for Immune Cell Stimulation12:55

Purification of Human S100A12 and Its Ion-induced Oligomers for Immune Cell Stimulation

Published on: September 29, 2019

Related Concept Videos

Determinants of Bacterial Pathogenicity and Virulence01:20

Determinants of Bacterial Pathogenicity and Virulence

Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...
Bacterial Toxins01:12

Bacterial Toxins

Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
Antimicrobial Proteins01:23

Antimicrobial Proteins

Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
Selectins01:25

Selectins

Cell adhesion is  an essential aspect of multicellularity. While stable cell interactions usually occur between cells of the same type, transient cell interactions occur between cells of different tissue types, such as between neutrophils and endothelial cells. Selectins are one class of cell adhesion molecules (CAMs) that bind carbohydrate ligands to form transient cell adhesion. They are rod-like proteins with a long extracellular part of variable length ending with the lectin domain, which...
Complement System01:27

Complement System

The complement system is a group of approximately 20 plasma proteins that strengthen the body's defenses against infections through opsonization, inflammation, and cell lysis. Opsonization involves coating pathogens with complement proteins, making them more recognizable and facilitating phagocyte engulfment. Certain complement proteins induce inflammation that attracts immune cells to the site of infection. Cell lysis involves the destruction of pathogens through the formation of a membrane...