Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

OHSU researchers demonstrate how white blood cells cannibalize virus-infected cells

05.10.2006
Research helps explain how the human immune system works, possible new way to measure vaccine effectiveness

Researchers at the Vaccine and Gene Therapy Institute (VGTI) at Oregon Health & Science University have demonstrated how certain white blood cells literally eat virus-infected cells while fighting disease at the microscopic level. The research not only helps provide a clearer understanding of the body's immune system, it also offers hope of a new method for gauging vaccine effectiveness. The research is published in the current edition of the journal Nature Medicine.

CD8+ T-cells are specialized white blood cells that serve an important role in the body's immune system. The cells attack and destroy disease "invaders" such as viruses in the body. Previous studies indicated that T-cells may consume parts of cells with which they interact, but this new research shows this can happen in response to a systemic viral infection.

"If you use a fluorescent dye to stain infected cells, you can literally watch T-cells consume membranes and outer surfaces of diseased cells. As they destroy and cannibalize the fluorescently labeled cells, they become labeled with the fluorescent dye themselves," explained Mark Slifka, Ph.D., a researcher in the VGTI who led the research. Slifka is also a scientist in the Division of Pathobiology and Immunology at the Oregon National Primate Research Center and holds a concurrent appointment in the Department of Molecular Microbiology and Immunology in the OHSU School of Medicine.

"While we don't fully understand why this happens, one possibility is that the T-cell consumes virus-infected cells to fuel itself in the continued fight against an ongoing infection. It's sort of like invaders that pillage their defeated foe's supplies and then continue the fight."

The way in which Slifka and his colleague, Carol Beadling, made this discovery was quite serendipitous. The researchers were studying the interactions between virus-specific T-cells and fluorescently labeled infected cells when they noticed that the T-cells also began to glow with the fluorescent dye. Further investigation revealed that the CD8+ T-cells, often referred to as "killer" T-cells, were literally ingesting parts of the virus-infected cells that they were attacking.

Slifka and Beadling's findings follow a discovery by David Parker, Ph.D., a professor of Molecular Microbiology and Immunology in the OHSU School of Medicine. Parker and his colleague, Scott Wetzel, noted a similar behavior in CD4+ T-cells, often called "helper" T-cells, which are less aggressive T-cells but also an important aspect of the immune system.

"Another interesting finding for our lab is that in some ways, T-cells can be picky eaters," explained Slifka. "Although they will destroy almost any infected cell, they prefer to eat certain types of cells but not others. For instance, we noted that CD8+ T-cells consumed other white blood cells such as infected B-cells, but they were not fond of eating infected fibroblasts, a type of cell found in connective tissue. They're sort of like a 5-year-old who loves to eat cookies, but refuses to eat their brussels sprouts."

The researchers believe that these findings may be useful as a method for determining a vaccine's effectiveness during the process of immunization. Measuring the levels at which CD8+ T-cells respond to and consume a candidate vaccine could likely determine whether that vaccine is effective in educating the body's immune system as to what diseases to look for.

Jim Newman | EurekAlert!
Further information:
http://www.ohsu.edu

Further reports about: OHSU Slifka T-cell fluorescent virus-infected white blood cell

More articles from Life Sciences:

nachricht Ambush in a petri dish
24.11.2017 | Friedrich-Schiller-Universität Jena

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

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...

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

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>