Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Emory scientists track down immune sentinel cells with gene gun

01.09.2003


Dendritic cells monitor foreign substances in the body and communicate whether they present a danger to the rest of the immune system. Emory immunologists have developed a sensitive method to detect and follow dendritic cells by marking them with a change in their DNA, and have discovered that they are more numerous and longer lived than other scientists had previously observed. Their research uses a gene gun, which shoots DNA into the skin using microscopic gold pellets, and could lead to a faster and simpler way to vaccinate against emerging diseases like West Nile virus, SARS, or hepatitis C.



The research was published online August 10, and will appear in the journal Nature Immunology in September. Lead authors are Sanjay Garg PhD, postdoctoral fellow, and Joshy Jacob, PhD assistant professor of microbiology and immunology at Emory University School of Medicine and the Yerkes National Primate Research Center. Both are members of the Emory Vaccine Center.

Dendritic cells, the security cameras of the immune system, derive their name from their finger-like projections. They continually capture external proteins, digest the proteins into fragments, and display those fragments on their surfaces. T cells, the police who watch the cameras, have the ability to examine the fragments on the dendritic cells’ surfaces and sound the alarm to the rest of the immune system if they determine that those fragments are dangerous. Although other kinds of cells also have the ability to present fragments of foreign proteins to the immune system, dendritic cells are the most proficient, and immunologists call them "professional" antigen-presenting cells.


Dendritic cells migrate between the skin, where one might expect to first encounter an intruder, and the lymph nodes, where T cells and other white blood cells congregate. Dr. Jacob’s group used transgenic mice engineered with a marker gene that can be easily detected by staining, but only when that gene is rearranged by an external signal. They shot the trigger signal – DNA encoding a specialized bacterial enzyme - into the skin of the mice. All the cells in the skin received the trigger signal, but only the dendritic cells migrated to the draining lymph nodes.

Dr. Jacob estimates that there are 1,000 dendritic cells for every square millimeter of skin. His group found that the number of dendritic cells that migrate into the lymph nodes is 100 times higher than previously thought, and that they live for two weeks, rather than just a few days. The scientists were able to observe the dendritic cells more accurately because the cells were marked permanently.

"This research resolves a long-standing puzzle," says Dr. Jacob. "T cells that will recognize a given foreign protein are quite rare, so it was hard to imagine how the T cells and dendritic cells would ever meet. It is still remarkable that they do."

The gene gun used to send the DNA into the skin uses gold pellets coated with the DNA. The pellets have a diameter of one micrometer and are driven with the force of a bullet. Dr. Jacob suggests that the DNA provides just enough of a signal to induce the dendritic cells, which are activated by inflammation or physical trauma, then migrate to the lymph nodes.

The gene gun could present an attractive alternative to conventional ways of making vaccines, Dr. Jacob notes. "Usually, you have to figure out how to grow a virus, then inactivate it so that it doesn’t actually cause an infection. This new methodology could take advantage of the immunizing capabilities of abundant, long-lived dendritic cells."

Holly Korschun | EurekAlert!
Further information:
http://www.emory.edu/

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>