Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UIC researchers discover how HIV rapidly infects immune cells

02.05.2003


Solving a longstanding scientific puzzle, researchers at the University of Illinois at Chicago have not only discovered how the body’s first line of defense against dangerous microbes inadvertently helps HIV rapidly infect the human immune system.



They’ve filmed the process as well.

In a remarkable series of movies created with images from time-lapse microscopy, UIC microbiologists Thomas Hope and David McDonald have documented how HIV enters human T cells, where it multiplies with abandon and eventually subverts the entire immune system, causing AIDS.


The movies show how HIV co-opts the very mechanism the body has evolved to defend itself against such pathogens.

"A picture is worth a thousand words," Hope said, quoting a colleague at a recent scientific meeting. "A video is worth a million."

The paper detailing the findings was accepted for publication in Science less than two weeks ago and was rushed to print in the May 1 online version of the journal called Science Express, which highlights scientifically important and newsworthy studies.

In the early stages of any infection, the dendritic cells of the immune system -- the first responders -- spring into action. These are the "garbage men of the body," as Hope calls them, constantly patrolling the neighborhood, looking for garbage to clean up.

Normally, when the dendritic cells find a piece of garbage -- a virus or other pathogen -- they pick it up and degrade it into tiny bits. They then show those bits to the T cells, alerting these executives of the garbage company to the potential danger.

The dendritic cells do this by making physical contact with the T cells, forming a tight interface, called an immunological synapse, through which the cells talk to one another via molecular signals.

If they make the right connection, the T cells then mobilize the rest of the immune system, sending out the trucks -- other immune cells -- to hunt for the garbage that the dendritic cells spotted, destroy the material, and save the body from disease.

While dendritic cells pick up HIV, however, they don’t destroy all the virus. Instead, scientists recently discovered, they inadvertently encourage infection, somehow helping HIV more rapidly infect the T cells.

McDonald said the "somehow" has now been answered.

Using a fluorescent dye that makes HIV particles glow green, Hope and McDonald photographed living dendritic cells with HIV particles inside. When the cells made contact with other cells, the HIV particles began streaming toward the juncture.

Not only that, but certain surface proteins on T cells necessary for infection by HIV also moved to the point of contact.

Further images clearly showed HIV particles transferring from the dendritic cells into the T cells through that same site -- the "infectious synapse," as the researchers call it.

Just as the immunological synapse signals the start of the immune response, so the infectious synapse jump-starts infection.

"HIV exploits the dendritic machinery for its own ends, taking advantage of the cells’ special relationship with T cells to gain entry and launch its assault," McDonald said. "Moreover, HIV doesn’t get destroyed in the process."

"What viruses do is try to find weak points in the immune system and take advantage of them," Hope said. "It’s a billion-year-old war: the body builds defenses against viruses, and the viruses find ways to thwart those defenses."

The researchers are particularly excited about their finding because it may apply to other pathogens. Recent studies have shown that Ebola virus, cytomegalovirus and the bacterium that causes tuberculosis all hitch rides on the dendritic cells just as HIV does.

"These pathogens appear to have discovered the same weak point in the immune system and exploited it," Hope said. "If true, then we may have discovered an important target for therapies that would combat not just HIV but many infectious diseases."

Sharon Butler | EurekAlert!
Further information:
http://www.uic.edu/

More articles from Health and Medicine:

nachricht Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>