Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


"Self-recovery" from Hepatitis C Infection Linked to Genes


In a study to be published in Science online Aug. 6, researchers at Johns Hopkins have found that genes involved in suppressing the body’s defensive "killer" immune cells are a potential key factor in spontaneous recovery from hepatitis C. The viral infection of the liver can lead to cirrhosis, cancer and even death. This genetic factor was found in people assumed to be exposed to a low dose of virus at the time of infection.

"Our findings may help explain why some of the 20 percent of people infected with hepatitis C manage to recover on their own, while the remaining 80 percent remain infected and may need treatment," said one of the study’s lead authors, infectious disease specialist Chloe Thio, M.D., assistant professor of medicine at The Johns Hopkins University School of Medicine.

In determining how some patients self-recover, the scientists hope one day to develop a vaccine and improve therapies for hepatitis C.

"Hepatitis C infection is a serious disease with few treatments, and it takes a heavy toll among disadvantaged Americans, including those who have weakened immune systems and are HIV positive," said Thio. "Our results were surprising in that self-recovery is not so much a function of speeding up the body’s immune system to attack the hepatitis C virus as it is about taking the foot off the brakes so the body’s killer immune cells can take off."

Using a DNA analysis of the blood from more than 1,000 patients infected with hepatitis C, of whom 350 recovered on their own without therapy, the researchers were able to determine what genetic characteristics were more common in those who self-recovered than in those who did not.

They found that the genes for a key protein, a receptor called KIR2DL3, in combination with genes for its key ligand, or attaching molecule called HLA, were more common in patients who self-recovered from hepatitis C. This combination was active only in those patients who were homozygous for this KIR2DL3-HLA, meaning two copies of the gene, one from each parent, were required for self-recovery to happen. Among those who received a presumed low viral dose, two copies of the KIR2DL3-HLA receptor-ligand combination were found in 20 percent who self-recovered from their infection, while it was present in just 10 percent who did not self-recover.

An important function of the KIR receptors is suppressing the action of the body’s killer immune cells, serving as a chemical signal to not attack otherwise healthy cells. Conversely, when the KIR receptors are not suppressing the immune system, the killer immune cells can be activated and turned on to rid unwanted cells from the body, such as bacteria and viruses like hepatitis.

The researchers focused their efforts on the genes involved with killer immune cells because earlier studies in animals had shown that natural killer cells were more active in those who self-recovered from hepatitis C infection than in those who did not.

"It remains to be explained how these genes and viral dose at the time of infection interact in determining self-recovery from hepatitis C," added Thio. "It can only be hypothesized at this point that high-dose infections possibly overwhelm the body’s killer immune system, whereas low-dose infections do not."

"This study puts the spotlight on activating or not activating the inhibitory signals of the innate immune response," said a senior study author and infectious disease specialist David Thomas, M.D., professor of medicine at Hopkins. "Whether it is possible to manipulate these very specific signals to promote recovery from hepatitis C remains to be seen. In the meantime, this finding is an important step forward in our understanding of hepatitis C recovery."

Funding for this multinational study was provided by the National Institutes of Health, the Centers for Disease Control, Hope Charity and the Medical Research Council, National Health Service, United Kingdom.

Other investigators in this research, led by Mary Carrington at the National Cancer Institute, were Salim Khakoo, Collin Brooks and William Rosenberg, Southhampton University, U.K.; Maureen Martin, Xiaojian Gao, Jie Cheng, James Goedert, and Stephen O’Brien, also from the National Cancer Institute; David Vlahov, New York Academy of Medicine; Margaret Hilgartner, New York Presbyterian Hospital-Cornell Medical Center; Steven Cox and Ann-Margaret Little, The Royal Free Hospital, London, U.K.; Graeme Alexander, University of Cambridge, U.K.; Matthew Cramp, Derriford Hospital, Plymouth, U.K.; and Jacquie Astemborski, also from Hopkins.

Hepatitis C is the leading cause of liver disease in the United States and the most serious form of hepatic infection. It affects more than 4 million people in the United States, with an estimated 10,000 to 12,000 deaths each year. Hepatitis C is transmitted by contact with blood and other body fluids of an infected person, through sexual activities, injection drug use, sharing of personal care items or direct contact.

| newswise
Further information:

More articles from Life Sciences:

nachricht How Does Friendly Fire Happen in the Pancreas?
21.10.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Strong, steady forces at work during cell division
20.10.2016 | University of Massachusetts at Amherst

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Innovative technique for shaping light could solve bandwidth crunch

20.10.2016 | Physics and Astronomy

Finding the lightest superdeformed triaxial atomic nucleus

20.10.2016 | Physics and Astronomy

NASA's MAVEN mission observes ups and downs of water escape from Mars

20.10.2016 | Physics and Astronomy

More VideoLinks >>>