Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists replicate hepatitis C virus in laboratory

23.02.2005


New in vitro model system will allow study of therapeutics and virus life cycle



For the first time, scientists have replicated hepatitis C virus (HCV) in the laboratory. The ability to replicate HCV in cell culture will allow researchers to better study the life cycle and biology of this virus and to test potential antiviral compounds, which may lead to new therapies for the liver disease that results from infection with HCV. Scientists at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), one of the National Institutes of Health (NIH), conducted the study, which appears in the Feb. 15, 2005 issue of Proceedings of the National Academy of Sciences (PNAS).

"Until recently, research on this infectious disease has suffered from the lack of a robust in vitro model system," says T. Jake Liang, M.D., Chief of the Liver Diseases Branch of the NIDDK and co-author of the study. "Our model system produced viral particles that have all the properties of the whole virus. This evidence together with an analysis of the replicated viral RNA supports a conclusion of viral replication and production."


The NIDDK group used a strain of HCV that would have applications to the greatest number of people – genotype 1, the major type of HCV of human infections worldwide and the type most resistant to current therapies. They constructed an HCV replica using a DNA copy of the original HCV single-strand RNA genome. They placed the DNA copy between two ribozymes, RNA molecules that have enzymatic function and can cleave RNA sequence at specific locations. These two ribozymes were designed to generate the correct ends of the HCV genome and to act as start and stop buttons to gene activity. The construct was "naked," meaning that it contained only nucleic acids, the genetic material of the virus, and did not have the HCV viral envelope, a protective shell of lipids and proteins that surrounds the viral RNA in fully-formed HCV. The naked HCV construct was then placed into human liver cells in a cell culture medium.

The NIDDK scientists found evidence of HCV proteins and HCV RNA within the human liver cells in the culture. Electron microscopy showed evidence of high levels of viral particles resembling fully-formed HCV outside of the human liver cells in the culture medium. The researchers believe that the HCV construct contained within the human liver cells behaved like a true HCV infection by producing fully formed copies of the virus and releasing them from the host cell into the culture medium. Further testing is needed before the researchers can determine if the viral particles produced in this system are in fact infectious. Also, this system only represents the tail end of the viral life cycle – viral replication, assembly and release from host cells. Another HCV model system is needed to show the beginning stages of the viral life cycle – viral entry into host cells and viral activity in the host cell before replication.

"With this cell-based system, we can screen compounds with a cell-based assay to look for inhibitors of virus replication," says Liang. "We can also apply this technique to develop model systems for other similar viruses."

HCV is a small, enveloped, single-stranded RNA virus in the family Flaviviridae. HCV is a major cause of liver disease in the United States and the world. One in a series of hepatitis viruses, HCV accounts for about 15 percent of acute hepatitis cases, 60 to 70 percent of chronic hepatitis cases, and up to 50 percent of cases of cirrhosis, end-stage liver disease, and liver cancer. Almost 4 million Americans, or 1.8 percent of the U.S. population, have antibodies to HCV indicating ongoing or previous infection with the virus. Approximately 10,000 to 12,000 deaths each year in the United States are due to HCV.

Marcia Vital | EurekAlert!
Further information:
http://www.nih.gov

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>