Featured Research

from universities, journals, and other organizations

Keeping viruses at bay: How our immunosensory system attacks viruses on a molecular level

Date:
August 11, 2014
Source:
Universität Bonn
Summary:
Our immunosensory system detects virus such as influenza via specific characteristics of viral ribonucleic acid. Previously, it was unclear how the immune system prevents viruses from simply donning molecular camouflage in order to escape detection. An international team of researchers has now discovered that our immunosensory system attacks viruses on a molecular level. In this way, a healthy organism can keep rotaviruses, a common cause of diarrheal epidemics, at bay.

In the laboratory: Marion Goldeck, Dr. Martin Schlee (sitting), Dr. Winfried Barchet, Thomas Zillinger and Prof. Dr. med. Gunther Hartmann, Director of the Institute of Clinical Chemistry and Clinical Pharmacology of the University of Bonn Hospital.
Credit: Claudia Siebenhüner/UKB

Our immunosensory system detects virus such as influenza via specific characteristics of viral ribonucleic acid. Previously, it was unclear how the immune system prevents viruses from simply donning molecular camouflage in order to escape detection. An international team of researchers from the University of Bonn Hospital and the London Research Institute have now discovered that our immunosensory system attacks viruses on a molecular level. In this way, a healthy organism can keep rotaviruses, a common cause of diarrheal epidemics, at bay. The results have been published in the renowned journal "Nature."

Related Articles


Every day our bodies are confronted with a variety of viruses and other pathogens. Our immune systems must constantly decide what is "foreign" and what is part of the body itself so that the body's own cells are not inadvertently attacked by its own defense troops. Viruses imitate the body's own structures and thus represent a special challenge for the immune system. In this way, the immune system works like a sensory organ which continuously detects dangers and initiates the appropriate defense mechanisms. This immunosensory system searches for viruses by surveilling the body's own ribonucleic acid (RNA) for RNA with characteristics typical of viruses. In RNA viruses, RNA is the carrier of the virus's genetic information. To reproduce, viruses must multiply their RNA, and this multiplication leads to the development of molecular patterns which are in turn used to detect the viruses themselves.

It has been known for some time that RIG-I-like receptors (RLRs) play a crucial role in the detection of RNA viruses. These receptors act as "fire alarms" within the immune system: When RNA molecules from viruses bind to these receptors, a signal chain is initiated that leads to the production of substances that can ultimately combat the viruses. "During amplification of viral RNA, a so-called triphosphate group, consisting of three phosphates, inevitably develops at one end of the newly formed RNA. A few years ago, we were the first to show that it is this triphosphate group which allows RIG-I to detect newly formed viral RNA. Previously, it was believed that viruses can elude this detection via simple deceptive molecular maneuvers," said Prof. Gunther Hartmann, Director of the Institute of Clinical Chemistry and Clinical Pharmacology of the University of Bonn Hospital.

RIG-I: A molecular attack against viruses

Together with scientists from the Immunobiology Laboratory of the London Research Institute in England, the scientists working with Dr. Martin Schlee and Prof. Dr. Gunther Hartmann at the University of Bonn Hospital investigated the immunorecognition of reoviruses. This family includes rotaviruses, which cause serious diarrheal illness and are responsible for the deaths of more than a million children worldwide every year. The immunorecognition of reoviruses was previously unclear since their RNA does not contain a triphosphate group. Now the researchers discovered that, surprisingly, an RNA structure with two phosphates at the end of the RNA double-strand in reoviruses can likewise trigger RIG-I and alarm the immune system.

"This finding has significance for the detection of RNA viruses that extends far beyond reoviruses: It is comparatively simple for a virus to molecularly change the triphosphate in the course of its development," said Dr. Schlee. The first step in this process is generally to split off the outermost phosphate of the triphosphate group, which leads to a diphosphate. This step is necessary for the virus to perform further modifications to its RNA and thus don a molecular cloak of invisibility. However, any form of further molecular camouflage is made extremely difficult for the virus due to the additional highly specialized RIG-I-mediated immunorecognition of the diphosphate. Thus, RIG-I attacks the virus on both fronts, significantly restricting its further development. "Without the investigation into reoviruses, we would not have discovered this universal mechanism of virus detection," said Prof. Hartmann. Since members of the reovirus family also contain a diphosphate group in their viral RNA, a healthy organism can also detect these viruses and curb these illnesses within a few days. However, malnourished children cannot summon these reserves, and the illness can become life-threatening.

The immune system: a sensory system for health

The researchers see a major application potential in the decoding of virus detection: "We are already currently developing artificially produced copies of viral RNA in order to alert our immune system to viruses in a targeted fashion," said Prof. Hartmann who is also director of the project "Novel Anti-infective Agents" at the German Centre for Infection Research (DZIF). Prof Hartmann is also currently speaker of the Cluster of Excellence ImmunoSensation, which is supported by a 28-million Euro grant from the German Research Foundation (DFG). The Cluster brings together experts from a variety of disciplines at the site and connects them to international research structures.


Story Source:

The above story is based on materials provided by Universität Bonn. Note: Materials may be edited for content and length.


Journal Reference:

  1. Delphine Goubau, Martin Schlee, Safia Deddouche, Andrea J. Pruijssers, Thomas Zillinger, Marion Goldeck, Christine Schuberth, Annemarthe G. Van der Veen, Tsutomu Fujimura, Jan Rehwinkel, Jason A. Iskarpatyoti, Winfried Barchet, Janos Ludwig, Terence S. Dermody, Gunther Hartmann, Caetano Reis e Sousa. Antiviral immunity via RIG-I-mediated recognition of RNA bearing 5′-diphosphates. Nature, 2014; DOI: 10.1038/nature13590

Cite This Page:

Universität Bonn. "Keeping viruses at bay: How our immunosensory system attacks viruses on a molecular level." ScienceDaily. ScienceDaily, 11 August 2014. <www.sciencedaily.com/releases/2014/08/140811124636.htm>.
Universität Bonn. (2014, August 11). Keeping viruses at bay: How our immunosensory system attacks viruses on a molecular level. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2014/08/140811124636.htm
Universität Bonn. "Keeping viruses at bay: How our immunosensory system attacks viruses on a molecular level." ScienceDaily. www.sciencedaily.com/releases/2014/08/140811124636.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) — Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) — A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) — Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins