Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Experimental vaccine protects mice against deadly 1918 flu virus

19.10.2006
Federal scientists have developed a vaccine that protects mice against the killer 1918 influenza virus. They also have created a technique for identifying antibodies that neutralize this virus, a tool that could help contain future pandemic flu strains.

These findings are important, the researchers say, to understanding and preventing the recurrence of the H1N1 influenza virus that caused the 1918 pandemic and to protecting against virulent flu strains in the future, including the H5N1 avian flu virus. Details of the research are available online this week in Proceedings of the National Academy of Sciences.

Gary J. Nabel, M.D., Ph.D., director of the Vaccine Research Center (VRC) at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), led the research team in developing the experimental vaccines and conducting the immunological studies in mice. Terrence Tumpey, Ph.D., of the Centers for Disease Control and Prevention (CDC) conducted vaccine studies in mice involving the live, reconstructed 1918 flu virus in a biosafety level 3-enhanced laboratory at the CDC in Atlanta--one of four types of specialized biosafety labs where scientists study contagious and potentially deadly materials under high-level safety and contamination precautions designed to protect the researchers and prevent microorganisms from entering the environment.

"Understanding why this influenza virus was so deadly is an extremely important question," says NIAID Director Anthony S. Fauci, M.D. "By building upon earlier research where scientists successfully reconstructed the 1918 pandemic flu strain, Dr. Nabel and his colleagues have demonstrated that this virus is vulnerable to intervention. This knowledge will help further our continued efforts to develop treatments and vaccines to protect us against another deadly flu pandemic."

... more about:
»DNA »H5N1 »Nabel »Vaccine »immunized »neutralizing »pandemic

The 1918-1919 influenza pandemic was the most deadly flu outbreak in modern history, killing 50 million or more people worldwide.

"A key to containing pandemic flu viruses is to understand their vulnerabilities and determine whether they can evade immune recognition," says Dr. Nabel. "What we learn about the H1N1 virus that caused the 1918 pandemic is pertinent to other pandemic viruses and to the development of effective and universal vaccines."

Using the genetic sequence information for the 1918 flu virus, Dr. Nabel and his VRC colleagues created plasmids--small strands of DNA designed to express specific characteristics--carrying genes for the virus' hemagglutinin (HA) protein, the surface protein found in all flu viruses that allows the virus to stick to a cell and cause infection. The researchers created two types of plasmids: one to reflect the HA found in the original 1918 flu virus; the other an altered HA protein designed to attenuate (weaken) the virus.

Mice were then injected with a DNA vaccine containing both types of plasmids to determine whether they would generate immune responses to the 1918 virus. The researchers found significant responses both in terms of production of T-cells, the white blood cells critical in the immune system's battle against invading viruses, as well as the production of neutralizing antibodies.

To determine the vaccine's protective effects, the CDC's Dr. Tumpey intranasally exposed a group of mice to live, reconstructed 1918 virus 14 days after they were immunized with the experimental DNA vaccine. All 10 vaccinated mice survived the challenge with the deadly virus. To explore how the vaccine protected the animals, the researchers first depleted other mice of T-cells; however, this had no effect on the immunity of the vaccinated mice to the 1918 virus. In contrast, the researchers discovered that transferring antibody-rich immunoglobulin (IgG) from immunized mice to non-immunized mice resulted in antibody levels in the animals at levels only slightly lower than those that were immunized. Further, when the animals were exposed to the reconstructed 1918 flu virus, 8 of 10 mice that received antibodies from the immunized mice survived; none of the 10 mice that received IgG from the unvaccinated control group survived.

"By using an existing pandemic flu strain, this research will provide the basis for design of alternative vaccines against influenza viruses with enhanced virulence," says Dr. Tumpey.

Although the researchers are not discounting the potential role T-cells may have in combating flu viruses, they concluded that in this study, the experimental DNA vaccine protected the mice by stimulating antibodies capable of neutralizing the 1918 flu virus.

"Who would have imagined five years ago that we'd be able to create a vaccine that protects against one of the deadliest forms of influenza the world has ever seen?" adds Dr. Nabel. "It's because the 1918 flu virus has been reconstructed that we are now able the further understand it. Hopefully, this virus will help us to develop effective vaccine strategies for current pandemic influenza virus threats."

To evaluate the vaccine's antibody-inducing capabilities while minimizing exposure of lab personnel to the 1918 flu virus, Dr. Nabel and his VRC colleagues also created artificial viruses, or pseudoviruses, featuring the HA of the 1918 flu virus but stripped of the ability to cause infection. The pseudoviruses were then incubated with antibody-containing blood samples from the mice immunized with the DNA vaccine and those that were not. The researchers found that the antibodies from the immunized mice neutralized the pseudoviruses while the blood samples from the mice that were not immunized had no effect. This method was also effective in identifying neutralizing antibodies to the H5N1 avian flu virus and could be used to screen for monoclonal antibodies that may be used as an antiviral treatment, according to Dr. Nabel.

"This technique would be very useful in defining evolving serotypes of flu viruses like H5N1 to develop immune sera and neutralizing monoclonal antibodies that may help to contain pandemic flu," says Dr. Nabel.

The study authors indicate that further testing will be needed to determine whether DNA vaccination can confer immune protection in people similar to that seen in the study mice. Additionally, the use of DNA-based vaccines are being explored as a potential strategy for creating vaccines to protect against the H5N1 avian flu virus.

Kathy Stover | EurekAlert!
Further information:
http://www.nih.gov
http://www.niaid.nih.gov

Further reports about: DNA H5N1 Nabel Vaccine immunized neutralizing pandemic

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>