Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alcohol increases hepatitis C virus in human cells

27.06.2003


Drinking may compromise treatment success



A team of NIH-supported researchers today report that alcohol increases replication of the hepatitis C virus (HCV) in human cells and, by so doing, may contribute to the rapid course of HCV infection. The researchers tested the actions of alcohol in HCV replicon--viral HCV-ribonucleic acid or HCV-RNAs that, when introduced into human liver cell lines, replicate to high levels. In separate laboratory experiments they showed that:

  • alcohol increases HCV replication at least in part by upregulating a key cellular regulator of immune pathways and function known as nuclear factor kappa B (NF-kappa B):

  • alcohol inhibits the anti-HCV effect of interferon-alpha (INF-alpha)therapy; and

  • treatment with the opioid antagonist naltrexone abolishes alcohol actions.


Wenzhe Ho, M.D., and Steven D. Douglas, M.D., Department of Pediatrics, University of Pennsylvania, and the Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, and colleagues in the Department of Psychiatry, University of Pennsylvania School of Medicine report their results in the July 2003 issue of Hepatology (Volume 38, Number 1, pages 57-65).

Speculating that alcohol somehow promotes HCV expression, the researchers relied on a recently available cellular system for studying the dynamics of virus replication (developed and provided to the investigators by Drs. C. M. Rice, The Rockefeller University, and Christoph Seeger, Fox Chase Cancer Center) to demonstrate for the first time that alcohol enhances HCV replicon expression at both the messenger RNA and protein levels. In the cell lines used for the study, the research team also showed that alcohol activation of NF-kappa B was responsible for increasing HCV expression. "Although the replicon system mimics only some aspects of HCV replication, we have identified at least a likely mechanism whereby alcohol increases viral load and thus may become an important cofactor in HCV severity," Dr. Douglas said.

"These findings are immediately useful to clinicians for counseling HCV-positive patients about alcohol use," said Ting-Kai Li, M.D., Director, National Institute on Alcohol Abuse and Alcoholism (NIAAA). "For clinical and basic scientists, they raise new research questions, many of which no doubt will be explored using the model and methods introduced today." NIAAA supported the experiments through a grant to Dr. Douglas, whose work also was supported by the National Institute of Mental Health and the National Institute on Drug Abuse (NIDA). The NIAAA and NIDA supported Dr. Ho’s work on the study.

HCV is an RNA virus of the flavivirus family that infects about 4 million U.S. residents and produces some 30,000 new infections each year. HCV typically escapes clearance by the immune system and leads to persistent, chronic infection in 70 to 85 percent of infected individuals, of whom fewer than 50 percent respond to IFN-alpha, the HCV therapy of choice. Over the long term, HCV infection can lead to cirrhosis, liver failure, and liver cancer. As a group, HCV-infected individuals are the major recipients of liver transplantation.

Clinicians have long observed a high incidence of HCV infection in heavy drinkers, including those without other risk factors such as intravenous drug abuse or history of blood transfusions. In addition, the virus is more likely to persist in heavy drinkers and to lead to such complications as cirrhosis and liver cancer. Suspected mechanisms for the latter effects include alcohol’s capacity to compromise immune function and enhance oxidative stress. The role of alcohol use in HCV acquisition has been more of a mystery.

During the 1990s, several studies reported higher blood levels of HCV in drinkers than abstainers and in habitual than infrequent drinkers. Further, drinking reduction was shown to diminish the number of virus particles in the blood. These observations led Dr. Douglas and his colleagues to pursue the role of alcohol in HCV replication.

Using the same replicon, Drs. Ho, Douglas and their colleagues also demonstrated that alcohol compromises IFN-alpha action against HCV and explored a plausible mechanism for alcohol’s role in HCV expression. Alcohol interferes with endogenous opiates, which have a key role in its addictive properties. The researchers found that the opiate receptor antagonist naltrexone, better known for its utility in helping alcoholism treatment patients to avoid relapse, not only blocked the promoting effect of alcohol on HCV expression but also diminished alcohol activation of NF-kappa B in these cells. "These data strongly suggest that activation of the endogenous opioid system is implicated in alcohol-induced HCV expression," the authors conclude.



For an interview with Dr. Douglas, please telephone 215-590-1978; for an interview with Dr. Ho, please telephone 215-590-4462. For an interview with NIAAA staff members, please contact the NIAAA Press Office. Publications and additional alcohol research information are available at http://www.niaaa.nih.gov.

The National Institute on Alcohol Abuse and Alcoholism, a component of the National Institutes of Health, U.S. Department of Health and Human Services, conducts and supports approximately 90 percent of U.S. research on the causes, consequences, prevention, and treatment of alcohol abuse, alcoholism, and alcohol problems and disseminates research findings to science, practitioner, policy making, and general audiences.

Ann Bradley | EurekAlert!
Further information:
http://www.niaaa.nih.gov/

More articles from Health and Medicine:

nachricht A 'half-hearted' solution to one-sided heart failure
24.11.2017 | Boston Children's Hospital

nachricht New study points the way to therapy for rare cancer that targets the young
22.11.2017 | Rockefeller University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>