Featured Research

from universities, journals, and other organizations

Model of viral lifecycle could help in finding a cure for hepatitis B

Date:
August 4, 2014
Source:
Massachusetts Institute of Technology
Summary:
A new technique sustains hepatitis B in liver cells, researchers have discovered, allowing for the study of immune response and drug treatments. Around 400 million people worldwide are infected with the hepatitis B virus (HBV); of those, one-third will go on to develop life-threatening complications, such as cirrhosis and liver cancer. Although there is an effective HBV vaccine, only around 50 percent of people in some countries where the disease is endemic are vaccinated. A complete cure for the disease is very rare, once someone has been chronically infected.

An electron micrograph shows the presence of hepatitis-B virus.
Credit: Courtesy of the Centers for Disease Control and Prevention

A new technique for studying the lifecycle of the hepatitis B virus could help researchers develop a cure for the disease.

Related Articles


In a paper published in the journal Proceedings of the National Academy of Sciences, Sangeeta Bhatia of MIT and Charles Rice of Rockefeller University describe using microfabricated cell cultures to sustain hepatitis B virus in human liver cells, allowing them to study immune responses and drug treatments.

Around 400 million people worldwide are infected with the hepatitis B virus (HBV); of those, one-third will go on to develop life-threatening complications, such as cirrhosis and liver cancer.

Although there is an effective HBV vaccine, only around 50 percent of people in some countries where the disease is endemic are vaccinated. A complete cure for the disease is very rare, once someone has been chronically infected.

"Once a liver cell is infected, the viral genome persists inside the nucleus, and that can reactivate later," says Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology and Electrical Engineering and Computer Science. "So although we have a vaccine, it's important to find a way to study this persistent form of the virus to try to identify treatments that could efficiently clear it."

'Finicky' Hepatocytes

To develop a treatment for HBV, researchers need to be able to study infected liver cells, known as hepatocytes, so they can understand how the virus interacts with them.

But while researchers have previously been able to infect cultures of human hepatocytes with HBV, the cells' limited lifespan has made it difficult to study the virus, says Bhatia, who is also a Howard Hughes Medical Institute investigator and a member of MIT's Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science.

"That's because the hepatocyte -- the main cell in the liver -- is unstable," she says. "It's a very finicky cell, and when you isolate it from the liver and try to culture it under conventional conditions, it rapidly loses its repertoire of liver functions."

So the team set out to develop a technique to keep the liver cells stable and functioning long enough to monitor their response to the virus and antiviral drugs.

They based their approach on a system they had previously developed for studying the hepatitis C virus, in which they were able to successfully infect human hepatocytes with the virus and use it to compare antiviral regimens.

The hepatocytes are first patterned onto surfaces dotted with tiny spots of collagen, and then surrounded by supportive tissue made up of stromal cells, which act as connective tissue and support the hepatocytes in carrying out their liver functions.

Two Complementary Systems

To apply the technique to infection with HBV, the researchers developed two complementary systems. One uses primary hepatocytes obtained from livers donated for transplant; the second uses stem cells derived from human skin samples and guided into hepatocyte-like cells, Bhatia says.

When they compared the relative merits of the two systems, they found that the primary liver cells had a stronger immune response when infected with the virus than the stem cell progeny. However, unlike the primary hepatocytes, the hepatocyte-like cells offer an unlimited supply of test cells, since the researchers can simply grow more as required, Bhatia says.

"But that being said, both systems were able to grow this persistent nuclear form [of HBV], so we think they offer complementary tools," she says.

To investigate whether the cell cultures could be used to test new treatments for the disease, the researchers monitored their response to two existing drugs. They found that the infected cultures responded to the drugs in the same way that liver cells inside the body are known to do. This means the systems could be used to help predict how effective new treatments will be in eradicating the virus from liver cells, Bhatia says.

Having developed the technique, the researchers now plan to begin using it to investigate new treatments for HBV. They also plan to use the model to study liver cells' natural antiviral response in more detail, and in particular to try to understand why cells from different donors have different immune responses to the disease.


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Helen Knight. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Shlomai, R. E. Schwartz, V. Ramanan, A. Bhatta, Y. P. de Jong, S. N. Bhatia, C. M. Rice. Modeling host interactions with hepatitis B virus using primary and induced pluripotent stem cell-derived hepatocellular systems. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1412631111

Cite This Page:

Massachusetts Institute of Technology. "Model of viral lifecycle could help in finding a cure for hepatitis B." ScienceDaily. ScienceDaily, 4 August 2014. <www.sciencedaily.com/releases/2014/08/140804151417.htm>.
Massachusetts Institute of Technology. (2014, August 4). Model of viral lifecycle could help in finding a cure for hepatitis B. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2014/08/140804151417.htm
Massachusetts Institute of Technology. "Model of viral lifecycle could help in finding a cure for hepatitis B." ScienceDaily. www.sciencedaily.com/releases/2014/08/140804151417.htm (accessed October 23, 2014).

Share This



More Health & Medicine News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Fears Keep Guinea Hospitals Empty

Ebola Fears Keep Guinea Hospitals Empty

AP (Oct. 23, 2014) Fears of Ebola are keeping doctors and patients alike away from hospitals in the West African nation of Guinea. (Oct. 23) Video provided by AP
Powered by NewsLook.com
Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
More People Diagnosed With TB In 2013, But There's Good News

More People Diagnosed With TB In 2013, But There's Good News

Newsy (Oct. 22, 2014) The World Health Organizations says TB numbers rose in 2013, but it's partly due to better detection and more survivors. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins