Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists observe how a close bond activates the immune system

18.11.2005


The immune system is highly complex. The cast of characters alone required to marshal an immune response to a foreign invader can number in the millions as the body’s soldiers, T cells, are called into action. What triggers this complex response begins when T cells and dendritic cells, another type of immune cell, form a kind of molecular embrace, or immunological synapse, to relay information about intruders.



The communication between these immune cells hasn’t been well understood because scientists had no suitable techniques to manipulate it. Now that problem has been solved. In a new study scientists at New York University School of Medicine and the University of California, Berkeley, report that they have observed the exchange of information between immune cells that is required to spark a body wide response to infection.

"This is the first time that anyone has been able to physically manipulate the immunological synapse and measure the effect on T cell signaling," says Michael L. Dustin, Ph.D., the Irene Diamond Associate Professor of Immunology and Associate Professor of Pathology at NYU School of Medicine, and one of the lead authors of the study.


The research by Dr. Dustin and Jay T. Groves of University of California, Berkeley, and their colleagues is a fusion of biology and nanotechnology--devices at the molecular scale. The study sheds new light on the workings of T cells, the body’s most specific and potent line of defense against viruses, bacteria, and other pathogens, says Dr. Dustin who is also an investigator in the molecular pathogenesis program at NYU’s Skirball Institute of Biomolecular Medicine.

The study, published in the November 18, 2005, issue of Science, reveals how T cells analyze and react to the signals of infection at the immunological synapse.

Every T cell wears a unique molecule, called a T cell antigen receptor, on its surface that it uses to detect pieces of foreign proteins called antigens. These receptors exist in astonishing, and for all practical purposes, unlimited variety--allowing the body to recognize any pathogen it might encounter.

Just as police need evidence of a crime to begin an investigation, T cells must recognize a specific antigen before they start to fight an infection. Dendritic cells constantly scour the body for antigens and present these to T cells for review in the lymph nodes. It is a demanding job. "Just 10 dendritic cells can show viral antigens to over a million T cells in a day," says Dr. Dustin.

Once a T cell’s antigen receptor finds an antigen match, the T cell forms an immunological synapse with a dendritic cell through which it queries the dendritic cell for additional information about the antigen and its source in the body. Is the antigen a danger or simply a harmless food protein? The interrogation may last hours, and if the antigen is deemed a threat the T cell starts multiplying, eventually producing thousands of copies of itself. These T cell clones are capable of killing invaders outright and marshaling other cells to destroy them.

In the new study, Gabriele Campi, a graduate student in Dr. Dustin’s laboratory, and Kaspar Mossman, a graduate student of Dr. Groves’s, created a synthetic dendritic cell using purified antigen and adhesion molecules (molecules that the cell can grip) in a thin fluid coating on a glass surface. In prior studies the antigen was free to move over the entire glass surface, but in this study they set up miniscule chrome barriers, allowing them to modify the pattern of T-cell antigen receptor clusters in the immunological synapse.

Previous research has shown that T cell receptors cluster in a bull’s eye-pattern at the interface between the T cell and the synthetic dendritic cell but the significance of this arrangement has been unknown. Thanks to the chrome barriers, Dr. Dustin and his colleagues discovered that the T cell receptor signal is strongest when they are physically held in the outer ring of the bull’s eye rather than the center.

"We locked the receptors in the periphery and saw enhanced signaling over a prolonged period of time. It was quite a surprise," says Dr. Dustin. Researchers had speculated that the concentrated bull’s eye structure somehow allowed T cells to maintain their state of activation. But the new work shows that it is actually the outer edge of immunological synapse that boosts activation, not the center.

Dr. Dustin’s group is now conducting additional experiments to see if dendritic cells actively present proteins to T cells in patterns that stimulate the periphery of the bull’s eye in the immunological synapse, using molecular organization to provide information about the precise nature of the threat associated with the antigen.

Pam McDonnell | EurekAlert!
Further information:
http://www.nyumc.org

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>