Navigation Links
Immune exhaustion driven by antigen in chronic viral infection
Date:5/13/2009

A main reason why viruses such as HIV or hepatitis C persist despite a vigorous initial immune response is exhaustion. The T cells, or white blood cells, fighting a chronic infection eventually wear out.

Researchers at Emory Vaccine Center have demonstrated that exhaustion is driven by how the immune system detects infecting viruses.

To recognize the presence of a viral infection, T cells must be presented with bits of viral protein in a molecular frame supplied by other cells in the body -- called MHC (major histocompatibility complex) class I molecules.

In mice infected by lymphocytic choriomeningitis virus (LCMV), T cells became more or less exhausted depending on how much properly framed viral protein was available.

Insights from the research could guide efforts to revive the immune system in people with chronic viral infections. The results are published online this week in the Proceedings of the National Academy of Sciences.

Working with Vaccine Center director Rafi Ahmed, PhD, postdoctoral fellow Scott Mueller, PhD, examined the effects of limiting what kind of cells could display the viral antigens.

Ahmed is professor of microbiology and immunology at Emory University School of Medicine and a Georgia Research Alliance Eminent Scholar.

By performing bone marrow transplants on genetically engineered mice, Mueller created mice with MHC class I molecules on blood and immune system cells but missing from other cells such as nerve cells and connective tissue. LCMV infects both cells that come from bone marrow and cells that don't. But the roles each type of cell plays in communicating the infection to the immune system is different.

"We were trying to sort out which of several factors contribute to T cell exhaustion, such as viral antigen, inflammation and where the immune system encounters the virus," Mueller says. "What came out of these experiments allowed us to answer a broad question: the role of antigen in driving exhaustion."

When injected with LCMV, the altered mice had more energetic and responsive T cells early during the infection. But later, the altered mice had much higher levels of virus and more exhausted T cells. This contrast demonstrates how the level of antigen present is the motor behind immune exhaustion during the chronic infection.

"Early on, the T cells were healthier because they saw less antigen, and only saw it on cells that came from bone marrow," Mueller says. "But later, the immune system had trouble getting rid of the virus because the T cells couldn't recognize infection in cells that were not able to present the viral antigens."


'/>"/>

Contact: Holly Korschun
hkorsch@emory.edu
404-727-3990
Emory University
Source:Eurekalert

Related medicine news :

1. Penn study finds pro-death proteins required to regulate healthy immune function
2. Immune deficiency linked to a type of eye cancer
3. Tumors use enzyme to recruit regulatory T-cells and suppress immune response
4. Melanoma drug revs immune cells but cancer cells ignore it
5. Study identifies key player in the bodys immune response to chronic stress
6. MedImmune Resolves FDA Observations Regarding Manufacturing Process for FluMist(R)
7. UVA researchers find important clue to immune infertility
8. M.D. Anderson-led team reports possible key to autoimmune disease
9. Their immune cells, fighting your cancer
10. MedImmune Licenses Reverse Genetics Technology to GlaxoSmithKline for Use in Influenza Vaccine Development and Production
11. Occupational exposures may be linked to death from autoimmune disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/28/2017)... ... March 28, 2017 , ... Oily skin is a common and unwelcomed occurrence in people of ... a lot to offer to the discussion of dealing with excess skin oil. “Oily skin ... many home remedies that can help remove the oily shine while keeping the skin fresh ...
(Date:3/28/2017)... ... March 28, 2017 , ... “A Prophets Bones”: a thrilling adventure that reveals the ... , “There were things that his parents and teachers had asked of him that he ... he was going to defy the Almighty Creator. There were some who would have felt ...
(Date:3/27/2017)... FL (PRWEB) , ... March 27, 2017 , ... ... new patients for clear braces. People who want straight teeth without the extensive ... Invisalign® in Clearwater, FL, without acquiring a referral. A custom-designed series of ...
(Date:3/27/2017)... ... 2017 , ... Drs. Justin Kolnick, Kara Diamond, Randall Barton, Keith Hope and ... key role this treatment plays in protecting oral health, along with the benefits of ... who need a root canal in White Plains, NY or their second location in ...
(Date:3/27/2017)... (PRWEB) , ... March 27, 2017 , ... A study ... Buckingham MD, and his colleague, Sudeep Roy, MD, was recently published in the ... Electrocautery Efficacy in Rhytidectomy” details Drs. Buckingham and Roy’s study on the use of ...
Breaking Medicine News(10 mins):
(Date:3/27/2017)... 2017  Sanderling Ventures, portfolio company, Torax Medical, ... of Johnson & Johnson. Torax manufactures and markets the ... gastro-esophageal reflux disease (GERD). The LINK device is ... the procedure is currently available in the U.S. ... was founded by Sanderling Ventures, Mayo Medical Ventures ...
(Date:3/27/2017)... TEL AVIV, Israel , March 27, 2017 ... focused on oncology and immunology, announced today that AGI-134, an ... recently announced acquisition of Agalimmune Ltd., will be featured at ... Meeting in Washington, DC to ... ...
(Date:3/27/2017)... , March 27, 2017 The ... reach USD 16.0 billion by 2025, according to a ... prevalence of chronic diseases is anticipated to be responsible ... which thereby widens the scope for growth during the ... bariatric population, which is highly susceptible to chronic diseases, ...
Breaking Medicine Technology: