Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

EBV-derived microRNAs silence immune alarm signals of the host cell

05.10.2016

Epstein-Barr virus (EBV) prevents infected cells from being attacked by the immune system. The virus drives production of small molecules, so-called microRNAs, that suppress alarm signals sent out by the infected cell. Scientists at Helmholtz Zentrum München have elucidated this previously unknown mechanism.

The EBV virus, first described by the English virologists Michael Epstein and Yvonne M. Barr, is found in the majority of the world’s population, but is usually held in check by the immune system. Nevertheless, the body is unable to eliminate this pathogen completely.


The Epstein-Barr virus (EBV) prevents infected cells from being attacked by the immune system.

Source: Prof. Georg Bornkamm / Helmholtz Zentrum München

The team of scientists led by Prof. Wolfgang Hammerschmidt, head of the Research Unit Gene Vectors at Helmholtz Zentrum München and a member of the German Center for Infection Research (DZIF), is striving to find out the reasons behind this.

Hide-and-seek: EBV makes itself invisible

“Our new studies show that by means of microRNAs, the virus prevents the infected cell from alerting the immune system,” said Hammerschmidt, summarizing the findings. EBV usually hides in B cells, a class of white blood cells. If they are infected by EBV, the virus induces the cells to proliferate and thus to expand the reservoir of viruses. The B cells usually respond with an alarm signal to the immune system: They present molecules of the virus on their surface and secrete inflammatory cytokines to attract immune cells.

“It's just this alarm signal that's suppressed by microRNAs made by the virus,” said Manuel Albanese, a scientist in the Research Unit Gene Vectors. His colleague Takanobu Tagawa added: “The microRNAs block production of the proteins that would ring this alarm.” The two doctoral students share the lead authorship of the two publications in the Proceedings of the National Academy of Sciences and in the Journal of Experimental Medicine.*

New approach may be promising for cancer therapy

Since the EBV virus drives division of B cells and thereby causes particular forms of cancer, the researchers are considering how to apply these findings to cancer therapy. “The mechanism we discovered renders killer T cells and helper T cells inactive, even when they directly face the infected cell,” said study leader Hammerschmidt.** “If it were possible to disrupt this blockade, this could be an interesting approach to treat cancer: the immune system could then better fight tumors that are triggered by EBV.“ For other diseases, clinical studies on active substances that shut off specific microRNAs have already started, the authors say.

Further Information

* microRNAs (miRNAs) are noncoding RNAs that play an important role in gene regulation and especially in the silencing of genes. Generally, they have a size of 21 to 23 nucleotides and are very short – hence the name.

** Killer T cells (also known as CD8 T cells) can destroy the infected cells, thus preventing the virus from multiplying. Helper T cells (also called CD4 T-cells) support them and also ensure the production of antibodies against the virus.

Background:
About a year ago, scientists of the Gene Vectors Research Unit at Helmholtz Zentrum München discovered another mechanism the EBV virus uses to hide in human cells. Here the LMP2A protein plays a crucial role: http://www.helmholtz-muenchen.de/en/press-media/press-releases/2015/press-releas...

Original Publications:
Tagawa, T. & Albanese, M. et al. (2016): Epstein-Barr Viral miRNAs Inhibit Antiviral CD4+ T Cell Responses Targeting IL-12 and Peptide Processing. Journal of Experimental Medicine, doi: 10.1084/jem.20160248

Albanese, M. & Tagawa, T. et al. (2016): Epstein-Barr virus miRNAs inhibit immune surveillance by virus-specific CD8+ T cells. Proceedings of the National Academy of Sciences (PNAS), doi: 10.1073/pnas.1605884113

The Helmholtz Zentrum München, the German Research Center for Environmental Health, pursues the goal of developing personalized medical approaches for the prevention and therapy of major common diseases such as diabetes and lung diseases. To achieve this, it investigates the interaction of genetics, environmental factors and lifestyle. The Helmholtz Zentrum München is headquartered in Neuherberg in the north of Munich and has about 2,300 staff members. It is a member of the Helmholtz Association, a community of 18 scientific-technical and medical-biological research centers with a total of about 37,000 staff members. http://www.helmholtz-muenchen.de/en

The Research Unit Gene Vectors studies EBV's molecular functions to understand how the virus contributes to different types of disease. The scientists analyse the immune system of virus carriers to find out how EBV and other herpes viruses are kept in check, and why immune control has failed in patients with disease. They also investigate the origins of cancers of the immune system - lymphoma and leukaemia. Their ultimate goal is to develop new drugs, vaccines and cell-based therapies in order to efficiently treat or – preferentially – prevent infectious diseases and cancer. http://www.helmholtz-muenchen.de/en/agv

At the German Center for Infection Research (DZIF), over 500 scientists from 35 institutions nationwide jointly develop new approaches for the prevention, diagnosis and treatment of infectious diseases. Their aim is to translate research results into clinical practice rapidly and effectively. With this, the DZIF paves the way for developing new vaccines, diagnostics and drugs in the fight against infections. http://www.dzif.de.

Contact for the media:
Department of Communication, Helmholtz Zentrum München - German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg - Tel. +49 89 3187 2238 - Fax: +49 89 3187 3324 - E-mail: presse@helmholtz-muenchen.de

Scientific Contact at Helmholtz Zentrum München:
Prof. Dr. Wolfgang Hammerschmidt, Helmholtz Zentrum München - German Research Center for Environmental Health, Research Unit Gene Vectors, Marchioninistraße 25, 81377 München - Tel. +49 89 3187 1506, E-mail: hammerschmidt@helmholtz-muenchen.de

Sonja Opitz | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

Further reports about: B cells EBV Environmental Health Helmholtz T cells diseases immune system miRNAs

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton 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: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>