Related Experiment Video

Updated: Feb 16, 2026

In Vitro Assay to Study Tumor-macrophage Interaction
08:36

In Vitro Assay to Study Tumor-macrophage Interaction

Published on: August 1, 2019

8.1K

Inactivation of M111 Protein Gene Modifies Streptococcus Pyogenes Interactions with Mouse Macrophages In Vitro

M A Suvorova1, T A Kramskaya2, A N Suvorov2

  • 1Institute of Experimental Medicine, St. Petersburg, Russia. maria_suvorova@mail.ru.

Bulletin of Experimental Biology and Medicine
|January 9, 2018
PubMed

Insights

Streptococcus pyogenes protein M111 suppresses host immune defenses by inhibiting macrophage responses and promoting bacterial evasion. This protein prevents reactive oxygen species (ROS) generation and stimulates anti-inflammatory cytokine IL-10 production.

Area of Science:

  • Microbiology
  • Immunology
  • Bacterial Pathogenesis

Background:

  • Streptococcus pyogenes utilizes various virulence factors to evade host immune responses.
  • Protein M is a key surface protein in S. pyogenes, known for its role in pathogenesis.

Purpose of the Study:

  • To investigate the immunomodulatory effects of S. pyogenes protein M111 on macrophage function.
  • To determine how protein M111 influences the host's innate immune response to bacterial infection.

Main Methods:

  • Incubation of mouse resident peritoneal macrophages with S. pyogenes Gurov strain and its isogenic M protein mutant.
  • Quantification of reactive oxygen species (ROS) including nitroxide and superoxide anions.
  • Measurement of cytokine production, specifically IL-6, IL-10, and IL-17.

Main Results:

  • Protein M111 demonstrated antiphagocytic activity, hindering macrophage engulfment of bacteria.
  • M111 prevented the formation of reactive oxygen species (ROS) by macrophages.
  • The presence of M111 significantly stimulated the production of the anti-inflammatory cytokine IL-10.

Conclusions:

  • S. pyogenes protein M111 acts as a virulence factor by modulating macrophage activity.
  • This protein contributes to bacterial immune evasion by suppressing key host defense mechanisms.
  • Protein M111 facilitates pathogen survival by dampening the inflammatory response and promoting escape from immune surveillance.
Keywords:
M proteinStreptococcus pyogenescytokinesmacrophagessuperoxide radicals

More Related Videos

Generation of a Gene-disrupted Streptococcus mutans Strain Without Gene Cloning12:06

Generation of a Gene-disrupted Streptococcus mutans Strain Without Gene Cloning

Published on: October 23, 2017

8.2K
Purification of a High Molecular Mass Protein in Streptococcus mutans09:51

Purification of a High Molecular Mass Protein in Streptococcus mutans

Published on: September 14, 2019

6.3K

Related Concept Videos

X-Inactivation01:58

X-Inactivation

The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results.
42.7K
Activation and Inactivation of G Proteins01:22

Activation and Inactivation of G Proteins

Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
11.7K
Proteins: From Genes to Degradation02:11

Proteins: From Genes to Degradation

Within a biological system, the DNA encodes the RNA, and the nucleotide sequence in the RNA further defines the amino acid sequence in the protein. This is referred to as “The Central Dogma of Molecular Biology” - a term coined by Francis Crick.  Central dogma is a firm principle in biology that defines the flow of genetic information within any life form. The two fundamental steps in central dogma are - transcription and translation.
Transcription is the synthesis of RNA...
14.6K
Proteins: From Genes to Degradation02:11

Proteins: From Genes to Degradation

4.6K
Gene-Environment Interactions01:20

Gene-Environment Interactions

Gene expression is a dynamic process that is significantly influenced by environmental factors. This interaction underlies the complex nature of biological development and the phenotypic differences observed among individuals, even among those with identical genetic makeups. Factors such as radiation, temperature, behavior, nutrition, and stress play pivotal roles in determining how genes are expressed. The concept of the reaction range is central to understanding this interaction. It posits...
1.3K
In-vitro Mutagenesis01:16

In-vitro Mutagenesis

To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes.
16.7K