Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Emory scientists track down immune sentinel cells with gene gun


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:

More articles from Life Sciences:

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

nachricht Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Generation of a Stable Biradical

22.03.2018 | Life Sciences

Scientists develop a room temperature maser to amplify weak signals

22.03.2018 | Life Sciences

Jacobs University supports new mapping of Mars, Mercury and the Moon

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>