Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists find mutations that let bird flu adapt to humans

16.11.2006
By comparing influenza viruses found in birds with those of the avian virus that have also infected human hosts, researchers have identified key genetic changes required for pandemic strains of bird flu.

The new work, reported in the Nov. 16 issue of the journal Nature, illustrates the genetic changes required for the H5N1 avian influenza virus to adapt to easily recognize the receptors that are the gateway to human cells.

"We identified two changes that are important," says Yoshihiro Kawaoka, the senior author of the Nature paper and a virologist at the University of Wisconsin-Madison School of Veterinary Medicine. "Both changes are needed for the H5N1 virus to recognize human receptors."

The new report provides a molecular blueprint for the genetic changes required to transform a virus that only infects birds to a virus capable of easily recognizing human receptors. Receptors are molecules on the surface of cells that permit the virus to dock with the cell and commandeer it to initiate a cascade of infection. By knowing what genetic changes are required for the virus to easily infect human cells, it may be possible to detect the emergence of pandemic strains earlier, providing public health officials and vaccine manufacturers with precious time to prepare for a global outbreak of highly pathogenic influenza. To be successful, a virus must be able to recognize and attach to a host cell. But human and avian influenza viruses recognize different cell receptors. Avian flu viruses have demonstrated an ability to evolve to easily infect humans by exchanging genes with human viruses that subsequently permit them to recognize human receptor molecules and gain easy access to cells, typically in the human respiratory system.

... more about:
»Kawaoka »Mutation »avian »flu »pandemic »receptor

The change is thought to occur when human patients are exposed at the same time to a human flu virus and an avian flu virus. Most viruses, including influenza, readily swap genes with one another.

In the new study, conducted by an international team of researchers, the viruses isolated from human patients in Vietnam and Thailand could recognize both human and avian cell receptors. By contrast, the viruses found in chickens and ducks could only recognize the receptors on avian cells.

The work helps flesh out the changes that have occurred in the worrisome strain of avian influenza virus known as H5N1, a strain some fear could be the organism that will trigger a pandemic of virulent human influenza. The avian virus has already changed dramatically from when it was first identified in 1997, says Kawaoka, who also holds an appointment at the University of Tokyo.

"There are big differences between the virus first found in 1997 and the virus we see now," Kawaoka explains. "We are watching this virus turn itself into a human pathogen."

The mutations found by Kawaoka's group have not yet conferred a complete ability on avian flu to easily recognize the topography of human cells, but they are key steps on that pathway. More mutations, says Kawaoka, will be required for the virus to fully adapt to humans, but it is not known how many mutations are needed for such a change.

However, if scientists are able to continue to monitor and secure viral isolates from humans infected with bird flu, they may be able to map a mutation trajectory that will help predict when the avian virus will cross the threshold to become a human pathogen.

The last two flu pandemics in 1957 and 1968 were caused by avian viruses that had accumulated enough genetic mutations to be considered hybrids of animal and human viruses, Kawaoka notes.

Yoshihiro Kawaoka | EurekAlert!
Further information:
http://www.vetmed.wisc.edu

Further reports about: Kawaoka Mutation avian flu pandemic receptor

More articles from Life Sciences:

nachricht Bioenergy cropland expansion could be as bad for biodiversity as climate change
11.12.2018 | Senckenberg Forschungsinstitut und Naturmuseen

nachricht How glial cells develop in the brain from neural precursor cells
11.12.2018 | Universitätsmedizin der Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

 
Latest News

Electronic evidence of non-Fermi liquid behaviors in an iron-based superconductor

11.12.2018 | Physics and Astronomy

Topological material switched off and on for the first time

11.12.2018 | Materials Sciences

NIST's antenna evaluation method could help boost 5G network capacity and cut costs

11.12.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>