Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Coat of proteins makes viruses more infectious and links them to Alzheimer's disease

27.05.2019

New research from Stockholm University and Karolinska Institutet shows that viruses interact with proteins in the biological fluids of their host which results in a layer of proteins on the viral surface. This coat of proteins makes the virus more infectious and facilitates the formation of plaques characteristic of neurodegenerative diseases such as Alzheimer's disease.

Are viruses dead or alive? Well... both. Viruses can only reproduce inside living cells and exploit the cellular machinery of their host to their benefit. However, before entering a host cell, viruses are just nanometer-sized particles, very similar to artificial nanoparticles used in medical applications for diagnosis and therapy.


Proteins in the fluid surrounding the target cell bind to a virus and can make it more infectious. The virus can also accelerate the formation of threadlike amyloid fibrils that play a part in Alzheimer's disease.

Credit: E. Wikander/Azote/Stockholm University

Usage Restrictions: Image may be used in connection with news articles related to Stockholm University.

Scientists from Stockholm University and Karolinska Institutet have found that viruses and nanoparticles share another important property; they both become covered by a layer of proteins when they encounter the biological fluids of their host before they find their target cell. This layer of proteins on the surface influence their biological activity significantly.

"Imagine a tennis ball falling into a bowl of milk and cereals. The ball is immediately covered by the sticky particles in the mix and they remain on the ball when you take it out of the bowl. The same thing happens when a virus gets in contact with blood or lung fluids that contain thousands of proteins. Many of these proteins immediately stick to the viral surface forming a so-called protein corona", Kariem Ezzat of Stockholm University and Karolinska Institutet explains.

Kariem Ezzat and his colleagues studied the protein corona of respiratory syncytial virus (RSV) in different biological fluids. RSV is the most common cause of acute lower respiratory tract infections in young children worldwide, leading up to 34 million cases and 196,000 fatalities each year. "The protein corona signature of RSV in the blood is very different from that in lung fluids.

It is also different between humans and other species such as rhesus macaque monkeys, which also can be infected with RSV", Kariem Ezzat says. "The virus remains unchanged on the genetic level. It just acquires different identities by accumulating different protein coronae on its surface depending on its environment. This makes it possible for the virus to use extracellular host factors for its benefit, and we've shown that many of these different coronae make RSV more infectious."

The researchers from Stockholm University and Karolinska Institutet have also found that viruses such as RSV and herpes simplex virus type 1 (HSV-1) can bind a special class of proteins called amyloid proteins. Amyloid proteins aggregate into plaques that play a part in Alzheimer's disease where they lead to neuronal cell death.

The mechanism behind the connection between viruses and amyloid plaques has been hard to find till now, but Kariem Ezzat and his colleagues found that HSV-1 is able to accelerate the transformation of soluble amyloid proteins into thread-like structures that constitute the amyloid plaques. In animal models of Alzheimer's disease, they saw that mice developed the disease within 48 hours of infection in the brain. In absence of an HSV-1 infection the process normally takes several months.

"The novel mechanisms described in our paper can have an impact not only on understanding new factors determining how infectious a virus is, but also on devising new ways to design vaccines. In addition, describing a physical mechanism that links viral and amyloid causes of disease adds weight to the increasing research interest in the role of microbes in neurodegenerative disorders such as Alzheimer's disease and opens up new avenues for treatments.", Kariem Ezzat of Stockholm University and Karolinska Institutet says.

###

The article

"The Viral Protein Corona Directs Viral Pathogenesis and Amyloid Aggregation" by Ezzat et al is published in Nature Communications. DOI: 10.1038/s41467-019-10192-2. The project is a collaboration between researcher from Stockholm University, Karolinska Institutet and University of Eastern Finland and others.

More information

Kariem Ezzat, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University and Department of Laboratory Medicine, Karolinska Institutet. Phone: + 46 8 16 14 37, mobile: +46 720 39 09 93, e-mail: kariem.ezzat@su.se

Anna-Lena Spetz, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University. Phone: +46 8 16 42 05, Mobile phone +46 707 47 13 03, e-mail: anna-lena.spetz@su.se

Media Contact

Kariem Ezzat
kariem.ezzat@su.se
46-081-61437

http://www.su.se/english 

Kariem Ezzat | EurekAlert!
Further information:
http://dx.doi.org/10.1038/s41467-019-10192-2

More articles from Life Sciences:

nachricht Monitoring biodiversity with sound: how machines can enrich our knowledge
18.06.2019 | Georg-August-Universität Göttingen

nachricht Uncovering hidden protein structures
18.06.2019 | Universität Konstanz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Uncovering hidden protein structures

18.06.2019 | Life Sciences

Monitoring biodiversity with sound: how machines can enrich our knowledge

18.06.2019 | Life Sciences

Schizophrenia: Adolescence is the game-changer

18.06.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>