Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Building better therapeutic vaccines for chronic infections

04.07.2005


Study finds that poor T cell responsiveness limits current approaches



In recent years, researchers have become increasingly interested in developing therapeutic vaccines. Most Americans are familiar with prophylactic, or preventive vaccines, which protect an individual from infections; examples include the common pediatric vaccines as well as the flu shot. But therapeutic vaccines are designed instead to be administered to patients who have already acquired chronic infections, such as HIV or hepatitis. These therapeutic vaccines aim to enhance the immune system’s ability to combat an infectious agent, such as a virus. Researchers are also developing therapeutic vaccines to treat a variety of cancers.

But many experimental therapeutic vaccines have thus far fallen short of expectations. Now, scientists at The Wistar Institute and Emory University offer details about what may prevent the immune system from responding effectively to a therapeutic vaccine during a state of chronic infection. Their findings suggest how scientists might alter therapeutic vaccination approaches to make the immune system respond better. Their work is published today in the Journal of Virology.


"In this study, we wanted to look at why therapeutic vaccines are generally less effective than prophylactic vaccines," says E. John Wherry, Ph.D., assistant professor in Wistar’s Immunology Program and lead author of the study. Wherry conducted the research as a postdoctoral fellow in the Emory University laboratory of Rafi Ahmed, Ph.D., before joining Wistar earlier this year. "What we found was that the T cells in the chronically infected mice responded poorly to the vaccine."

Specifically, Wherry says, the T cells failed to proliferate, or expand in number. This failure to proliferate seemed to correlate with a high viral load, which suggests several directions researchers might pursue in improving response to therapeutic vaccines.

"The ongoing stimulus to the immune system that occurs in chronic infection seems to prevent the immune cells from responding optimally to a therapeutic vaccine," Wherry says. "If we could lower viral load before therapeutic vaccination, we might be able to improve efficacy."

The next step for the research, Wherry says, will be to combine therapeutic vaccines with other modalities that either lower viral load or enhance T cell function, particularly the proliferative capacity of T cells. Possible examples include anti-virals that could be given prior to therapeutic vaccination, or a cytokine that might boost the proliferation or survival of responding cells.

Wherry’s group at Wistar is continuing to work on understanding at a fundamental level why the T cell proliferation is poor when a therapeutic vaccine is administered during a state of chronic infection. He is also planning to compare the immune response using different therapeutic vaccine platforms. While Wherry’s primary interest is in chronic infection, he notes that research in this area should inform the design of better therapeutic cancer vaccines as well because many of the deficiencies in immune response are similar whether the antigen confronting the immune system is a virus or a tumor.

In addition to Wherry and senior author Ahmed, the other co-author of the paper is Joseph N. Blattman, Ph.D., of Fred Hutchinson Cancer Research Center. Funding for the work was provided by the National Institutes of Health and the Cancer Research Institute.

Franklin Hoke | EurekAlert!
Further information:
http://www.wistar.org

More articles from Health and Medicine:

nachricht Correct connections are crucial
26.06.2017 | Charité - Universitätsmedizin Berlin

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

New 3-D model predicts best planting practices for farmers

26.06.2017 | Agricultural and Forestry Science

New research reveals impact of seismic surveys on zooplankton

26.06.2017 | Life Sciences

Correct connections are crucial

26.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>