Related Experiment Video
Updated: Dec 10, 2025
12:27
Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes
Published on: January 3, 2020
6.7K
Staphylococcus aureus Alpha-Toxin Limits Type 1 While Fostering Type 3 Immune Responses
Agnes Bonifacius1, Oliver Goldmann2, Stefan Floess1
1Department Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
Frontiers in Immunology
|August 28, 2020
Summary
Staphylococcus aureus alpha-toxin selectively kills CD4+ T helper 1 (Th1) cells while sparing Th17 cells. This finding reveals a novel immune evasion strategy and potential therapeutic targets for antibiotic-resistant bacterial infections.
Area of Science:
- Immunology
- Microbiology
- Infectious Diseases
Background:
- Antibiotic-resistant *Staphylococcus aureus* poses a significant global health threat.
- Alpha-toxin is a key virulence factor of *S. aureus*, disrupting host barriers and modulating immune cells.
- CD4+ T cell immunity is crucial for defense against *S. aureus* infections.
Purpose of the Study:
- To investigate the direct impact of *S. aureus* alpha-toxin on CD4+ T cell differentiation and function.
- To elucidate the mechanisms underlying alpha-toxin's immunomodulatory effects.
- To explore the therapeutic potential of targeting alpha-toxin's immune modulation.
Main Methods:
- Murine naive CD4+ T cells were differentiated into effector subsets *in vitro* in the presence of alpha-toxin.
- Cell viability, receptor expression (ADAM10), and caspase activation were assessed.
- *In vivo* studies examined T cell subset populations during *S. aureus* bacteremia.
Main Results:
- Alpha-toxin induced selective death of Th1-polarized CD4+ T cells but not Th17-polarized cells.
- Differential susceptibility to calcium-mediated activation-induced cell death may explain Th1 cell death.
- *In vivo*, alpha-toxin exposure led to a decrease in Th1 cells and an increase in Th17 cells during bacteremia.
Conclusions:
- *Staphylococcus aureus* utilizes alpha-toxin to directly modulate CD4+ T cell populations, favoring Th17 over Th1 responses.
- This immunomodulatory mechanism impacts both adaptive and innate immune cells, including lymphoid cells.
- Targeting alpha-toxin's effects on T cells offers a promising avenue for developing novel immune-based therapies against resistant *S. aureus*.
Related Concept Videos
01:27Allergic Drug Reactions
1.2K
Allergic reactions related to drugs are hypersensitivity responses driven by the immune system and bear no connection to the drug's therapeutic action. While drugs in isolation do not trigger an immune response, they can interact with endogenous proteins to form antigens. These antigens stimulate lymphocytes to produce antibodies. IgE-type antibodies attach themselves to mast cells. Upon subsequent exposure to the same stimulus, the antigen-antibody interaction is initiated, unleashing...
1.2K
01:31Defense Against Bacterial Pathogens
2.4K
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...
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...
2.4K
01:30Hypersensitivities
5.5K
Hypersensitivity, also known as a hypersensitivity reaction or allergic reaction, is a condition where the body's immune system reacts abnormally to a foreign substance. Such substances, that cause hypersensitivity are referred to as an allergen, could be something typically harmless to most people, like pollen or certain foods.
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...
5.5K
01:24T Cell Types and Functions
1.9K
When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
1.9K
01:36Types of Toxins
3.0K
Humans continually engage with an environment rich in potentially harmful chemicals. These are introduced to our bodies through inhalation, ingestion, or skin contact. These chemicals exist in various forms, such as air and environmental pollutants, agricultural chemicals, organic solvents, and heavy metals.
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
3.0K
01:27Cytotoxic T Cells-mediated Immune Response
6.2K
Cytotoxic T cells are a vital component of the immune system. They have the remarkable ability to identify and target antigens on infected or abnormal cells. These antigens often originate from intracellular pathogens such as viruses or abnormal proteins cancer cells produce.
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
6.2K