Cells help viruses during cell entry

An intact cell membrane is essential for any cell to function. The external cell membrane can be damaged by mechanical stress, for example in muscle cells, or by pathogens, such as viruses and bacteria. Membrane damage can result in small pores, which lead to loss of valuable substances from the cell.

The cell can quickly repair such injuries to its membrane. Human adenoviruses also cause small pores in the cell membrane, as a team of cell biologists headed by Urs Greber, a professor at the Institute of Molecular Life Sciences at the University of Zurich, has now discovered.

These pores are too small for the virus to get directly into the cell but are large enough for the cell to recognize them as a danger signal and repair them in a matter of seconds. The adenovirus uses this very repair mechanism to trigger an infection.

Certain lipids help the virus to enter the cell

During this repair process, lipids – in particular ceramide lipids – are formed, which enable the virus to enter the cell more rapidly. The ceramide lipids cause the membrane to bend and endosomes to form.

Endosomes are small bubbles of lipids and proteins and they engulf extracellular material, such as nutrients, but also viruses. With the aid of the ceramide lipids, the virus increases the size of the membrane lesions, and can leave the endosome before the endosome becomes a lysosome and degrades the virus.

The virus then multiplies in the nucleus and subsequently infects other cells. “We have identified particular cellular lipids as key components for the virus to enter into cells, which is surprising as lipids have important roles in biology, but these roles are difficult to identify,” explains Stefania Luisoni, the first author on the study and a doctoral student at the Institute of Molecular Life Sciences.

The scientists identified a connection between the formation of a membrane pore by the virus and a cellular repair mechanism. These events form a positive feedback loop, which is part of the explanation for the high infection efficiency of the adenoviruses, which scientists have known for some time.

The work also identified a new inhibitor against the adenoviruses, which inhibits the cellular protein “lysosomal acid sphingomyelinase“, and blocks the formation of ceramide lipids in the plasma membrane. “Our results are potentially interesting for the development of new anti-viral agents, and they increase our understanding in how the adenovirus works in vaccination and gene therapy” concludes Greber.

Literature:

Stefania Luisoni, Maarit Suomalainen, Karin Boucke, Lukas B. Tanner, Markus R. Wenk, Xue Li Guan, Michal Grzybek, Ünal Coskun, Urs F. Greber. Co-option of Membrane Wounding Enables Virus
Penetration into Cells. Cell Host & Microbe, July 8, 2015. http://www.sciencedirect.com/science/article/pii/S1931312815002541

http://www.mediadesk.uzh.ch

Media Contact

Nathalie Huber Universität Zürich

All latest news from the category: Life Sciences and Chemistry

Articles and reports from the Life Sciences and chemistry area deal with applied and basic research into modern biology, chemistry and human medicine.

Valuable information can be found on a range of life sciences fields including bacteriology, biochemistry, bionics, bioinformatics, biophysics, biotechnology, genetics, geobotany, human biology, marine biology, microbiology, molecular biology, cellular biology, zoology, bioinorganic chemistry, microchemistry and environmental chemistry.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors