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 A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

nachricht CWRU researchers find a chemical solution to shrink digital data storage
22.06.2017 | Case Western Reserve University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>