The related report by Lázaro et al, "Hepatitis C virus replication in transfected and serum-infected cultured human fetal hepatocytes," appears in the February issue of The American Journal of Pathology.
Hepatitis C virus (HCV) infection affects approximately 170,000,000 people worldwide. HCV liver disease, which may induce liver inflammation, cirrhosis, and/or hepatocellular carcinoma, represents the foremost reason for liver transplantation in much of the U.S.
Study of HCV replication within liver cells, or hepatocytes, has been hampered by a lack of adequate virus culture systems. Some systems allow the virus to infect cells but do not permit prolonged replication and production of virus, while other systems rely on derivatives of permissive virus isolates for efficient replication in transformed (mutated) cell lines. Still lacking has been a system to sustain replication of novel virus isolates from patients using nontransformed hepatocytes.
Nelson Fausto of the University of Washington School of Medicine has crossed this hurdle using a human fetal hepatocyte culture system that was previously developed in his lab. Using this system, his group has demonstrated sustained replication and production of virus particles for at least 2 months, with these virus particles able to infect new cells.
In their first experiments, Fausto and colleagues transfected hepatocyte cultures with HCV genomic RNA and found replication of HCV RNA genomes and production of core protein (for virus particle formation). Release of infectious virus particles was confirmed, as media from these cells were able to infect naive hepatocytes. Finally, virus particles were examined by electron microscopy and shown to possess the expected size and shape of HCV virus particles.
Once the system was established, the group examined whether sera from patients carrying HCV could infect the human fetal hepatocytes. When sera from patients infected with different HCV strains were added to the hepatocyte culture system, viral replication occurred and new virus particles were produced.
In both transfection and infection models, virus particles were released in a cyclical manner, with bursts of virus produced every 10-14 days. This is similar to what has been reported during clinical HCV infection, possibly due to the host's natural defenses. Interestingly, cultured hepatocytes responded to viral replication by displaying signs of distress and cell death and by expressing interferon-beta, a cellular antiviral, in an effort to control the infection.
This culture system provides a breakthrough in studying HCV replication in nontransformed hepatocytes, the natural target of the virus. By allowing infection by patient serum containing a wide array of virus strains, this system may allow better understanding of the differences between different strains, further improving treatment strategies.
Audra Cox | EurekAlert!
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences