Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Common Cold Virus Can Cause Polio In Mice When Injected Into Muscles

07.09.2004


Virologists at Duke University Medical Center have discovered that, under the right conditions, a common cold virus closely related to poliovirus can cause polio in mice.

The researchers injected a cold virus called Coxsackievirus A21 into mice that were engineered to be susceptible to this particular virus. However, instead of developing a cold, the mice unexpectedly displayed paralytic symptoms characteristic of polio. The researchers determined that administering the virus directly into muscles, instead of the virus’s normal home in the nasal cavity, was critical for development of polio.

The findings challenge traditional views as to what defines a poliovirus, said Matthias Gromeier, M.D., a Duke virologist and senior author of the study. "In principle, Coxsackieviruses could cause polio in humans," said Gromeier. "We are in the process of eradicating polio worldwide, but if we eliminate the poliovirus and cease polio vaccinations, our immune systems wouldn’t produce antibodies against polio, and Coxsackievirus could theoretically fill the niche of eradicated polio" he said. Results of the study will be published in the Sept. 6, 2004, issue of the Proceedings of the National Academy of Sciences.



Until now, it has been widely accepted that Coxsackievirus and poliovirus cause distinct illnesses because they bind to different docking sites, called receptors, on host cell surfaces. The current study turned that belief on its head, said Gromeier. Poliomyelitis has long been regarded as the signature of poliovirus, a virus that recognizes and binds to the CD155 receptor. However, the mice were genetically engineered to have only the Coxsackie A21 receptor, called ICAM-1, and they did not have the poliovirus receptor. Still, when the mice were injected with Coxsackievirus, it initiated infection through the ICAM-1 receptor, and caused symptoms of polio.

The manner in which the mice were infected with Coxsackievirus facilitated its unusual behavior inside the body, the study showed. The mice were injected with Coxsackievirus into their calf muscles, an unusual route of entry. Following the injection, the mice began to display symptoms of polio, including an abnormal gait, dropfoot, and lower hind limb paresis. The researchers were left wondering how this intramuscular portal of entry could affect the virus’s ability to access the types of cells normally infected by polio.

In studying the virus’ action within infected mice, they found that the virus traveled from the calf muscle where it was injected to the central nervous system along "motor neuron axons." Such axons extend from the central nervous system to muscles throughout the body and convey commands for muscle movement. The site in the muscle where axons physically attach is called a neuromuscular junction. These junctions likely served as the cold virus’ portal of entry into the nervous system.

"We gave the coxsackievirus a distinct advantage by injecting it directly into muscle, where it had direct access to the kinds of nerve cells polio normally attacks," said Gromeier. "The resulting polio symptoms were milder than those caused by the poliovirus, but it was polio nonetheless."

Such a subtle change in entry mode significantly changed the virus’ behavior, and therein lies one of the greatest dangers associated with viruses, said Gromeier. Viruses are extremely adaptable and they can alter themselves dramatically based upon their environment. Coxsackievirus A21 is one of a large group of cold viruses that are genetically very similar to polioviruses. "Our study reveals how similar these viruses actually are," he said. "It is fascinating that a minor change such as injection site may cause a harmless cold virus to attack the central nervous system."

Gromeier’s team is now collaborating with the Centers for Disease Control to test numerous Coxsackievirus samples from patients around the world. Their goal is to determine which genetic features of the Coxsackievirus induce polio and under what conditions.

Becky Levine | EurekAlert!
Further information:
http://www.mc.duke.edu

More articles from Life Sciences:

nachricht Fine organic particles in the atmosphere are more often solid glass beads than liquid oil droplets
21.04.2017 | Max-Planck-Institut für Chemie

nachricht Study overturns seminal research about the developing nervous system
21.04.2017 | University of California - Los Angeles Health Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>