Visualizing virus replication in three dimensions

May 07, 2009
This is the cover illustration of the newest issue of Cell Host & Microbes. In the background in gray is a normal, two-dimensional image of the virus on an electron microscope. The 3D model is superimposed. The tubules of the endoplasmic reticulum and inside them the balloon-like vesicles where the dengue virus replicates its genome can be seen. Credit: Hygiene Institute at Heidelberg University Hospital

Dengue fever is the most common infectious disease transmitted by mosquitoes - some 100 million people around the world are infected. Researchers at the Hygiene Institute at Heidelberg University Hospital were the first to present a three-dimensional model of the location in the human cell where the virus is reproduced.

Their research provides an insight into the exact process of and serves as a model for other viruses whose replication is still unclear, such as the . In addition, it offers new approaches for developing measures to prevent or treat dengue fever. Up to now, neither a vaccine nor a specific antiviral therapy exists.

Professor Dr. Ralf Bartenschlager, director of the Department of at the Heidelberg Hygiene Institute and his team, working in cooperation with colleagues from the European Molecular Biology Laboratory (EMBL) have published their study in the latest issue of the prestigious journal Cell Host & Microbes.

Viruses do not have a metabolism and cannot produce proteins from their genetic material (RNA or DNA) on their own. They can replicate only inside a host cell - but where and how exactly does this take place? The answer to this question is crucial for developing therapy.

Viruses transform human cell membranes for their purposes

Dengue viruses reproduce in what is known as the endoplasmic reticulum, a membrane network interconnected with the nuclear envelope; this is where proteins are synthesized. The dengue virus uses this membrane network and transforms it for its own use.

"We now know that viral RNA is replicated in vesicles in the endoplasmic reticulum and is secreted through tiny pores. We were also able to show that replication of the virus genome and its encapsulation in new virus particles are directly linked," said Professor Bartenschlager. The new virus genomes are secreted through pores into the intracellular space where they are incorporated into pre-stages of viruses and then penetrate the endoplasmic reticulum a second time. There they are enveloped in a membrane that disguises them for the cell so that they can be secreted like normal cellular material. The reproduction cycle can begin again.

More information: Sonja Welsch, Sven Miller, Ines Romero-Brey, Andreas Merz, Christopher Bleck, Paul Walther, Stephen D. Fuller, Claude Antony, Jacomine Krijnse-Locker, Ralf Bartenschlager, Composition and Three-Dimensional Architecture of the Dengue Replication and Assembly Sites, Cell Host & Microbes 2009, 5, 4.

Source: University Hospital Heidelberg (news : web)

Explore further: Research helps identify memory molecules

add to favorites email to friend print save as pdf

Related Stories

Penn researchers discover new mechanism for viral replication

Aug 16, 2007

Researchers at the University of Pennsylvania School of Medicine have identified a new strategy that Kaposi’s Sarcoma Associated Herpesvirus (KSHV) uses to dupe infected cells into replicating its viral genome. This allows ...

Recommended for you

Research helps identify memory molecules

17 hours ago

A newly discovered method of identifying the creation of proteins in the body could lead to new insights into how learning and memories are impaired in Alzheimer's disease.

Computer simulations visualize ion flux

18 hours ago

Ion channels are involved in many physiological and pathophysiological processes throughout the human body. A young team of researchers led by pharmacologist Anna Stary-Weinzinger from the Department of Pharmacology ...

Neutron diffraction sheds light on photosynthesis

18 hours ago

Scientists from ILL and CEA-Grenoble have improved our understanding of the way plants evolved to take advantage of sunlight. Using cold neutron diffraction, they analysed the structure of thylakoid lipids found in plant ...

DNA may have had humble beginnings as nutrient carrier

Sep 01, 2014

New research intriguingly suggests that DNA, the genetic information carrier for humans and other complex life, might have had a rather humbler origin. In some microbes, a study shows, DNA pulls double duty ...

Central biobank for drug research

Sep 01, 2014

For the development of new drugs it is crucial to work with stem cells, as these allow scientists to study the effects of new active pharmaceutical ingredients. But it has always been difficult to derive ...

User comments : 0