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 A one-way street for salt
21.09.2018 | Julius-Maximilians-Universität Würzburg

nachricht Nerve cells in the human brain can “count”
21.09.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

 
Latest News

Fraunhofer ISE with over 60 Contributions at the European PV Solar Energy Conference and Exhibition

21.09.2018 | Trade Fair News

558 million-year-old fat reveals earliest known animal

21.09.2018 | Earth Sciences

Neutrons produce first direct 3D maps of water during cell membrane fusion

21.09.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>