Getting personal with hep B vaccines

December 19, 2013, Agency for Science, Technology and Research (A*STAR), Singapore
Getting personal with hep B vaccines
A personalized blood treatment could help to eliminate chronic hepatitis B virus infections. Credit: theasis/iStock

Therapeutic vaccines that boost antiviral immunity provide an attractive alternative to drug therapy for people who are infected with the hepatitis B virus (HBV). Yet, the large amount of genetic diversity found in circulating HBV strains has hindered the development of a 'one-size-fits-all' post-exposure vaccine.

A*STAR scientists from the Singapore Institute for Clinical Sciences (SICS) and the Singapore Immunology Network have now devised a more personalized approach to HBV therapeutic vaccination. In collaboration with researchers from Singapore and Europe, the A*STAR team isolated and manipulated a type of white blood cell known as a monocyte to produce an HBV-specific in cell culture. If this can be replicated in the body, the same transformation could form the basis of a simple and effective vaccine therapy for individuals infected by HBV.

To find cells that stimulate HBV-targeted immunity, the researchers investigated whether various immune cells that commonly capture and store viral proteins—a mechanism that enables the subsequent activation of virus-killing T cells through a process known as 'antigen presentation'— captured a particular protein called the hepatitis B surface antigen (HBsAg). They extracted six different types of 'antigen-presenting cells' (APCs) from 28 people chronically infected with HBV, all of whom carried large quantities of HBsAg in their bloodstreams. Of all the APCs, they found that only one distinct population of monocytes—CD14-expressing monocytes—tested positive for HBsAg.

Yet these monocytes did not activate HBV-specific T cells on their own; first, the researchers had to manipulate the HBsAg-containing monocytes to form another type of immune cell called a dendritic cell. The dendritic cells, when mixed together with patient-derived blood samples, then stimulated the expansion of virus-killing T cells. "This means that we may be able to directly stimulate the antigen-presenting of patients to start an immune response that can be beneficial to clear the virus infection," says team member Adam Gehring, now at the St Louis University Medical Center in the United States.

Achieving the same feat in the human body remains a challenge, however. In cell culture, the were differentiated using a combination of immune-stimulating proteins called cytokines. If taken by people, this cytokine combination could have undesired effects on the immune system, says Antonio Bertoletti from the SICS, who led the research. But a safer method that only uses cytokines to promote HBV-specific immunity could provide something akin to "therapeutic vaccination without the vaccine," Bertoletti notes.

Explore further: Exposure to hepatitis B virus activates immunity in young people, suggesting benefits for earlier treatment

More information: Gehring, A. J., Haniffa, M., Kennedy, P. T., Ho, Z. Z., Boni. C. et al. "Mobilizing monocytes to cross-present circulating viral antigen in chronic infection." The Journal of Clinical Investigation 123, 3766–3776 (2013). dx.doi.org/10.1172/JCI66043

Related Stories

Exposure to hepatitis B virus activates immunity in young people, suggesting benefits for earlier treatment

February 27, 2013
Infectious disease experts have long thought that children, teenagers and young adults who are chronically infected with the hepatitis B virus (HBV) lack the immune cells needed to fight this pathogen. As such, physicians ...

Earlier treatment for young patients with chronic hepatitis B more effective in clearing virus

September 6, 2012
Scientists from A*STAR's Singapore Institute for Clinical Sciences (SICS), together with clinical collaborators from London , discovered for the first time that children and young patients with chronic Hepatitis B Virus infection ...

Patient, heal thyself: Solution to personalised treatment for chronic infections could lie in patient's own blood

September 20, 2013
A recent discovery by scientists at A*STAR's Singapore Institute for Clinical Sciences (SICS), in close collaboration with researchers at the Singapore Immunology Network (SIgN), provides hope for a new personalised treatment ...

New drug stimulates immune system to kill infected cells in animal model of hepatitis B infection

April 26, 2013
A novel drug developed by Gilead Sciences and tested in an animal model at the Texas Biomedical Research Institute in San Antonio suppresses hepatitis B virus infection by stimulating the immune system and inducing loss of ...

Vaccination campaign doubles HBV mutations

October 7, 2013
A universal infant vaccination campaign in China has led the Hepatitis B virus (HBV) to more than double its rate of "breakout" mutations. These mutations may enable the virus to elude the vaccine, necessitating new vaccination ...

Recommended for you

A new theory on reducing cardiovascular disease risk in binge drinkers

January 23, 2018
A new study shows that binge drinkers have increased levels of a biomarker molecule—microRNA-21—that may contribute to poor vascular function.

Flu infection study increases understanding of natural immunity

January 23, 2018
People with higher levels of antibodies against the stem portion of the influenza virus hemagglutinin (HA) protein have less viral shedding when they get the flu, but do not have fewer or less severe signs of illness, according ...

New long-acting approach for malaria therapy developed

January 22, 2018
A new study, published in Nature Communications, conducted by the University of Liverpool and the Johns Hopkins University School of Medicine highlights a new 'long acting' medicine for the prevention of malaria.

Virus shown to be likely cause of mystery polio-like illness

January 22, 2018
A major review by UNSW researchers has identified strong evidence that a virus called Enterovirus D68 is the cause of a mystery polio-like illness that has paralysed children in the US, Canada and Europe.

Creation of synthetic horsepox virus could lead to more effective smallpox vaccine

January 19, 2018
UAlberta researchers created a new synthetic virus that could lead to the development of a more effective vaccine against smallpox. The discovery demonstrates how techniques based on the use of synthetic DNA can be used to ...

Study ends debate over role of steroids in treating septic shock

January 19, 2018
The results from the largest ever study of septic shock could improve treatment for critically ill patients and save health systems worldwide hundreds of millions of dollars each year.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.