The innate immune system condemns weak cells to their death

The “survival of the fittest” principle applies to cells in a tissue – rapidly growing and dividing cells are the fit ones. A relatively less fit cell, even if healthy and viable, will be eliminated by its more fit neighbors. Importantly, this selection mechanism is only activated when cells with varying levels of fitness are present in the same tissue.

If a tissue only consists of less fit cells, then no so-called cell competition occurs. Molecular biologists from the University of Zurich and Columbia University are the first researchers to demonstrate in a study published in the scientific journal Science that this cellular selection process requires the innate immune system.

Innate immune system recognizes weaker cells

Using the fruit fly as a model the researchers demonstrate that during cell competition programmed cell death is activated in the weaker cells. This apoptosis is induced by the signaling protein “Spätzle” that docks onto Toll-related receptors. The Toll-related receptors are part of the ancient innate immune system and normally trigger a defense reaction to bacterial or fungal infection, but as shown by Meyer and colleagues it can also trigger apoptosis in relatively less fit cells.

“Less fit cells are recognized and eliminated with the help of the communication pathway in the innate immune system”, is how primary author Stefanie Meyer explains this astounding phenomenon. According to Professor Konrad Basler it is not yet clear whether the initial signal comes from the winner cells or the weaker loser cells. “We still don’t know whether this involves the voluntary or forced suicide of the less-fit cells.”

When the wrong ones win

Sometimes the stronger cell is not a healthy cell, for example during the development of a tumor cancer cells can “outcompete” their weaker neighbors. In this case it is the healthy cells that fall behind in terms of fitness and are consequently condemned to death by the cell competition mechanism.

“Cancer cells use the innate immune system to drive out the healthy cells”, sums up Laura Johnston from Columbia University. These new findings are of particular interest for cancer research and early detection of the disease. According to the researchers the innate immune system could serve to identify faster growing but not yet malignant cells – and thus represent a way to combat the disease at an early stage.

Further reading:
Stefanie Meyer, Marc Amoyel, Cora Bergantinos, Claire de la Cova, Claus Schertel, Konrad Basler, Laura Johnston, An ancient defense system operates in cell competition to eliminate unfit cells from developing tissues. Science. December 4, 2014. doi:10.1126/science.1258236

Contacts:
Claus Schertel
Institute of Molecular Biology
University of Zurich
E-Mail: claus.schertel@imls.uzh.ch
Tel. +41 44 635 31 92 / +41 77 460 38 47

Prof. Dr. Konrad Basler
Institute of Molecular Biology
University of Zurich
Tel. +41 44 635 31 10
Email: konrad.basler@imls.uzh.ch

Stefanie Meyer
Institute of Molecular Biology
University of Zurich
Email: stefanie.meyer@imls.uzh.ch

Bettina Jakob
Media Relations
University of Zurich
Tel. +41 44 634 44 39
Email: bettina.jakob@kommunikation.uzh.ch

Weitere Informationen:

http://www.mediadesk.uzh.ch

Media Contact

Bettina Jakob 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