Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A stepwise retreat: how immune cells catch pathogens

12.07.2007
Researchers discover dynamic properties of immune cells’ tentacles

To protect us from disease our immune system employs macrophages, cells that roam our body in search of disease-causing bacteria. With the help of long tentacle-like protrusions, macrophages can catch suspicious particles, pull them towards their cell bodies, internalise and destroy them. Using a special microscopy technique, researchers from the European Molecular Biology Laboratory (EMBL) now for the first time tracked the dynamic behaviour of these tentacles in three dimensions. In the current online issue of PNAS they describe a molecular mechanism that likely underlies the tentacle movement and that could influence the design of new nanotechnologies.

The long cell protrusions that macrophages use as tentacles to go fishing for pathogens are called filopodia. The internal scaffolds of these filopodia are long, dynamic filaments consisting of rows of proteins called actin. The filaments constantly grow and shrink by adding or removing individual actin building blocks. But the dynamic properties of the filopodia and the mechanical forces that they can apply are not fully understood. Using a special microscopy technique a team of researchers from the groups of Ernst Stelzer and Gareth Griffiths at EMBL could for the first time observe the tentacle dynamics in three dimensions and measure their properties to unprecedented detail.

“The filopodia stretch out from the cell surface and upon contact with a suspicious particle they attach to it and immediately retract to pull the particle towards the cell body,” says Holger Kress who carried out the research at EMBL and is now working at Yale University. “We expected the tentacles to move in a continuous, smooth process, but surprisingly we observed discrete steps of filopodia retraction.”

... more about:
»Dynamic »Myosin »filopodia »retraction »tentacle

Highly precise measurements allowed the scientists for the first time to determine the speed and the force of the retraction and revealed that each individual retraction step is 36 nanometres long. These parameters match the properties of a class of proteins called myosins suggesting them as the driving force of filopodia retraction. Myosins are motor proteins, proteins that move along actin filaments and transport cargo. Transporting the filopodia’s internal scaffold myosins help bringing about the retraction. Likely several copies of myosin proteins act in a synchronous fashion to bring about the tentacle motion.

“The insights we gained into the properties of filopodia retraction and the possible molecular mechanism underlying them could find applications in nanotechnology,” says Alexander Rohrbach a former member of Stelzer’s group who is now a professor at the University of Freiburg. “Future synthetic nano-machines must integrate themselves into a system and have to react flexibly to changes within the system. Precisely these properties we have now observed in filopodia retraction. The fascinating principles, which we are beginning to understand, will certainly influence the design of such machines.”

Anna-Lynn Wegener | alfa
Further information:
http://www.embl.org/aboutus/news/press/2007/09jul07/

Further reports about: Dynamic Myosin filopodia retraction tentacle

More articles from Life Sciences:

nachricht Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>