Related Experiment Video
Updated: Feb 13, 2026
06:58
Evaluation of LC3-II Release via Extracellular Vesicles in Relation to the Accumulation of Intracellular LC3-positive Vesicles
Published on: October 18, 2024
1.3K
Extracellular Vesicles Released from Mycobacterium tuberculosis-Infected Neutrophils Promote Macrophage Autophagy and
Violeta D Alvarez-Jiménez1, Kahiry Leyva-Paredes1, Mariano García-Martínez1
1Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Mexico City, Mexico.
Frontiers in Immunology
|March 10, 2018
Summary
Neutrophil-derived extracellular vesicles (EVs) combat tuberculosis by activating macrophages. These EVs promote the clearance of Mycobacterium tuberculosis (Mtb) through superoxide anion production and autophagy induction in macrophages.
Area of Science:
- Immunology
- Cell Biology
- Microbiology
Background:
- Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb).
- Neutrophils are key immune cells that interact with Mtb, releasing extracellular vesicles (EVs) involved in intercellular communication.
- The specific effects of Mtb-infected neutrophil-derived EVs (EV-TB) on macrophages remain incompletely understood.
Purpose of the Study:
- To characterize EVs released by human neutrophils under different stimulation conditions.
- To investigate the impact of EV-TB on macrophage activation and Mtb control.
- To elucidate the mechanisms by which EV-TB mediate macrophage responses.
Main Methods:
- Characterization of EVs from non-stimulated and stimulated human neutrophils (including Mtb-infected).
- Analysis of macrophage gene expression, cytokine production, and intracellular Mtb load after EV treatment.
- Assessment of autophagy markers (LC3-II) and superoxide anion production in macrophages.
Main Results:
- EVs from Mtb-infected neutrophils (EV-TB) differed in size and contained toll-like receptor (TLR) 2/6 ligands.
- EV-TB enhanced macrophage expression of CD80, CD86, TNF-α, and IL-6, while decreasing TGF-β.
- EV-TB reduced intracellular Mtb, increased superoxide anion production, and induced autophagy in macrophages, leading to reduced Mtb load.
Conclusions:
- Neutrophils release distinct EVs in response to various stimuli, including Mtb.
- EV-TB activate macrophages, promoting Mtb clearance via superoxide production and autophagy induction.
- Neutrophil-derived EVs play a novel role in the innate immune response against tuberculosis.
More Related Videos
Related Concept Videos
01:27Decreasing Function
312
A decreasing function describes a relationship where the output consistently declines as the input increases. This means that for any two input values, if one is greater than the other, the corresponding output is smaller. Mathematically, a function f is decreasing on an interval I if for every x1 < x2 in I, f (x1) > f (x2). This type of behavior is visually identified on a graph that slopes downward from left to right.The nature of a function can be analyzed by calculating...
312
01:27Autophagy
5.9K
Autophagy is a self-digesting process by which a cell protects itself from threats both within and outside the cell, ranging from abnormal proteins to invading bacteria. In this process, obsolete components of the cell and invading microbes are degraded by hydrolytic enzymes active in an acidic environment of the lysosomal lumen.
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
5.9K
01:42The Extracellular Matrix
89.5K
Overview
89.5K
01:29Decreased Body Temperature
1.1K
A decreased body temperature can occur in patients with hypothermia and frostbite. Heat loss with extended cold exposure overpowers the body's ability to create heat, resulting in hypothermia. Core temperature readings help classify hypothermia. Mild hypothermia is temperatures between 32 °C (89.6 °F) and 35°C (95 °F) and is caused by impaired thermoregulation. Moderate hypothermia is temperatures between 28 C (82.4 °F) and 32 °C (89.6 °F) caused by...
1.1K
01:14Decreased pulse rate
933
Bradycardia is a medical condition in which the heart rate is slower than normal. It occurs when the heart's natural pacemaker, the sinus node, generates slower electrical impulses than the standard rhythm. In adults, bradycardia is diagnosed when the pulse rate falls below 60 beats per minute, indicating a deviation from the normal heart rate range.
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with...
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with...
933
02:40The Eukaryotic Promoter Region
19.0K
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are...
19.0K