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 Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

nachricht The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>