Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017

Autophagy allows cells to degrade and recycle their cellular components. Researchers at UZH have now demonstrated that the autophagy machinery in certain immune cells leads to the immune system attacking the central nervous system. The researchers are using these findings as a basis to look into new approaches to treating autoimmune diseases such as multiple sclerosis.

Autophagy refers to a fundamental recycling process of cells that occurs in yeast, fungi, plants, as well as animals and humans. This process allows cells to degrade their own components and thus activate energy resources to be able to adapt to nutritional needs.


In multiple sclerosis, the immune system attacks the myelin sheaths of the nerve fibres (white).

Image: Ralwel/iStockphoto

Quelle: University of Zurich

In addition, autophagy plays a central role in steering an organism’s immune response. Autoimmune diseases arise from an abnormal immune response to a normal body part such as the central nervous system in patients with multiple sclerosis.

No autoimmune reaction without autophagy proteins

Led by Jan Lünemann from the Institute of Experimental Immunology at the University of Zurich, a team of neuroimmunologists has now found evidence for another aspect of this cellular “self-digestion”: Autophagy proteins are responsible for triggering autoimmune processes in a mouse model of multiple sclerosis.

Upon genetically switching off the autophagy protein ATG5 in certain immune cells, the researchers observed significantly lower levels of pathological T cells in the central nervous system of the mice. As a consequence, the animals failed to develop inflammation in the brain and spinal cord comparable with inflammation that develops in multiple sclerosis.

Immune cells target nerve cells

The researchers have now demonstrated that the autophagy protein ATG5 has an essential function when myelin antigens are presented to immune cells during inflammation processes in the central nervous system. “This reactivation process is thought to play a decisive role in the development of autoimmune neuroinflammation,” says Christian Keller, lead author of the study. In multiple sclerosis – one of the most common autoimmune diseases – T cells attack the myelin sheaths of the body’s own nerve fibers.

The immune cells are activated as soon as they come into contact with antigen-presenting cells. Dendritic cells are responsible for antigen presentation. When the myelin sheath becomes defective, the dendritic cells digest the isolation membrane through autophagy and present parts of it to pathological T cells entering the site of the inflammation. “This means they promote the progression of the disease,” explains Keller.

The team plans to use the latest findings as a basis for investigating tissue samples of patients suffering from multiple sclerosis to find out whether autophagy is particularly active in certain immune cells. “In the long run, we want to see whether these new immunopathology findings can be used to develop new treatments for multiple sclerosis,” says Jan Lünemann.

Literature:
Christian W. Keller, Christina Sina, Monika B. Kotur, Giulia Ramelli, Sarah Mundt, Isaak Quast, Laure-Anne Ligeon, Patrick Weber, Burkhard Becher, Christian Münz, and Jan D. Lünemann. ATG-dependent phagocytosis in dendritic cells drives myelin-specific CD4+ T cell pathogenicity during CNS inflammation. PNAS. December 11, 2017. DOI: 10.1073/pnas.1713664114

Contact:
Prof. Jan D. Lünemann, MD
Institute of Experimental Immunology
University of Zurich
Phone +41 44 635 37 10
E-mail: jan.luenemann@uzh.ch

Weitere Informationen:

http://www.media.uzh.ch/en/Press-Releases/2017/autophagy.html

Kurt Bodenmüller | Universität Zürich

More articles from Life Sciences:

nachricht Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology

nachricht Scientists generate an atlas of the human genome using stem cells
24.04.2018 | The Hebrew University of Jerusalem

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Quantum Technology for Advanced Imaging – QUILT

24.04.2018 | Information Technology

AWI researchers measure a record concentration of microplastic in arctic sea ice

24.04.2018 | Earth Sciences

Complete skin regeneration system of fish unraveled

24.04.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>