Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Firefly light illuminates course of herpes infection in mice

05.11.2002


Researchers are using a herpes virus that produces a firefly enzyme to illuminate the virus’s course of infection in mice and to help monitor the infection’s response to therapy. The work is published by scientists at Washington University School of Medicine in St. Louis in the December issue of the Journal of Virology.



"This study demonstrates the feasibility of monitoring microbial infections in living animals in real time," says study leader David A. Leib, Ph.D., associate professor of ophthalmology and visual sciences and of molecular microbiology. "The technique enables us to follow an infection over time as it progresses and resolves, and we can do this repeatedly using the same animal."

This technology may solve several problems in studying herpes infections and the genes that control them. To investigate the progress of an infection over a course of days, for example, researchers normally must sacrifice infected mice each day and analyze their tissues to determine the level of virus present. The process is further complicated by the fact that individual mice respond differently to infection.


"One must make a leap of faith that a mouse sacrificed on day three of an infection is responding to the virus in the same way as a mouse sacrificed on day two of the infection," says Leib.

This new technology, an imaging method known as in vivo bioluminescence, enables investigators to track changes in the viral population in the same animal day after day. The device is located in the Molecular Imaging Center at the University’s Mallinckrodt Institute of Radiology.

"This technology can be used to explore questions about this virus that are possible only by studying entire living animals over time," says Gary D. Luker, M.D., an assistant professor of radiology with the Molecular Imaging Center and first author of the paper.

"This is an excellent example of the unique information and new collaborations that are generated when we examine fundamental biological processes with molecular imaging tools," says David Piwnica-Worms, M.D., Ph.D., professor of radiology and of molecular biology and pharmacology and director of the Molecular Imaging Center.

The investigators first added a gene for luciferase, an enzyme produced by fireflies, to a strain of herpes simplex type 1 virus. After determining that the modified virus behaves in cells like the normal virus, they injected the modified virus into several locations in mice, including the brain and abdominal cavity.

Daily for nine days, the mice were injected with luciferin, a compound also produced by fireflies that emits light when exposed to luciferase. They then were anesthetized, placed in a light-free box and photographed using a charged-coupled device, or CCD camera. The camera captures light emitted through the tissues of the mouse by the actively replicating virus. The image produced by the camera shows the location and amount of virus in a mouse as areas of color, ranging from blue (low levels) to red (high levels), superimposed on a photograph of the anesthetized animal. Light produced by the luciferase-luciferin reaction is known as bioluminescence because it is generated by biological chemicals.

This imaging method enabled the investigators to monitor the infection as it spread and receded over nine days. In a second experiment, mice infected with the modified virus were treated with the antiviral drug valacyclovir. The investigators found that decreases in bioluminescence correlated with the decline in the amount of virus present.

The method works in part because bioluminescence produced by fireflies contains a significant amount of red light, which penetrates tissues more effectively than other wavelengths of light. This effect can be seen by shining a flashlight through a finger; it is red light that penetrates the finger.

The investigators next will use the imaging technique to study the course of herpes infection in mice lacking certain elements of the immune system to determine how different elements of the immune system influence the course of an infection.


Luker GD, Bardill JP, Prior JL, Pica CM, Piwnica-Worms D, Leib DA. Noninvasive bioluminescence imaging of Herpes simplex virus type 1 infection and therapy in living mice. Journal of Virology, 76(23), 12149-12161, Dec. 2002.

Funding from the National Institutes of Health, Research to Prevent Blindness and a Robert E. McCormick Scholarship supported this research.

Darrell E. Ward | EurekAlert!
Further information:
http://medinfo.wustl.edu/

More articles from Health and Medicine:

nachricht NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)

nachricht High speed video recording precisely measures blood cell velocity
15.11.2017 | ITMO University

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: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>