Featured Research

from universities, journals, and other organizations

Immune Cell Communication Key To Hunting Viruses

Date:
October 26, 2006
Source:
Thomas Jefferson University
Summary:
Immunologists have used nanotechnology to create a novel "biosensor" to solve in part a perplexing problem in immunology: how the immune system's killer T-cells hunt down invading viruses. They have found that surprisingly little virus can turn on killer T-cells, thanks to some complicated communication among "antigen presenting" proteins that recognize and attach to the virus, making it visible to the immune system. Presenting proteins cooperate, spreading a signal among receptors and boosting T-cell response.

Immunologists at the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia have used nanotechnology to create a novel “biosensor” to solve in part a perplexing problem in immunology: how immune system cells called killer T-cells hunt down invading viruses.

Related Articles


They found that surprisingly little virus can turn on the killer T-cells, thanks to some complicated communication among so-called “antigen presenting” proteins that recognize and attach to the virus, in turn, making it visible to the immune system. T-cell receptors then “see” the virus, activating the T-cells.

The researchers, led by Yuri Sykulev, M.D., Ph.D., associate professor of microbiology and immunology at Jefferson Medical College of Thomas Jefferson University, showed that different types of presenting proteins cooperate, spreading a signal among only a few T-cell receptors and boosting the T-cell response. This helps explain how only a few virus-infected cells can cause a killer T-cell response. They report their findings this week in an online edition of the Proceedings of the National Academy of Sciences.

Understanding how the immune system responds to viral threats, says Dr. Sykulev, is critical to finding better ways to manipulate it and could have implications for improved vaccine development.

To better understand how proteins are recognized by killer T-cells, Dr. Sykulev and his co-workers created a biosensor out of semiconductor nanoparticles called quantum dots. These served as a unique scaffold to carry presenting proteins (called Major Histocompatibility Complex (MHC) proteins) and the attached virus portion, mimicking the clustering of MHC proteins on the surface of target cells. The researchers were able to place many MHC complexes, both with virus and non-virus fragments, and compared what was recognized by specific T-cell receptors on killer T-cells.

What they found surprised them. While the nanoparticle specifically bound to the surface of T-cells with receptors recognizing the viral-MHC complex, the control – a biosensor that carried the same MHC protein with a different peptide not recognized by the T-cells – unexpectedly also binded almost as strongly. “When we have such an arrangement of MHC proteins, we were able to see something no one had seen before – a very strong contribution of non-viral peptide-MHC interaction with a co-receptor,” he says. “Such cooperativity we think can be achieved when MHC complexes are close to each other.

“We’ve shown that when we try to mimic the positioning of MHC protein on quantum dots, which we believe is similar to what it is on the cell membrane, we have this very strong binding. An important message is that a single virus-MHC complex recognized in the context of self-MHC complexes is sufficient to activate a T-cell response, which is amazing,” he says. “That’s the power of killer cells.

“We always suspected that recognition of other peptide MHCs, like self-peptide MHCs derived from normal proteins, could facilitate recognition, but it was not clear until now how this happened.” Dr. Sykulev notes that this finding is not only relevant to viral infected cells, but to tumor cells as well. Both usually express very low levels of proteins that killer cells recognize.


Story Source:

The above story is based on materials provided by Thomas Jefferson University. Note: Materials may be edited for content and length.


Cite This Page:

Thomas Jefferson University. "Immune Cell Communication Key To Hunting Viruses." ScienceDaily. ScienceDaily, 26 October 2006. <www.sciencedaily.com/releases/2006/10/061025170034.htm>.
Thomas Jefferson University. (2006, October 26). Immune Cell Communication Key To Hunting Viruses. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2006/10/061025170034.htm
Thomas Jefferson University. "Immune Cell Communication Key To Hunting Viruses." ScienceDaily. www.sciencedaily.com/releases/2006/10/061025170034.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins