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:10/13/2017)... OBISPO, Calif. (PRWEB) , ... October 13, 2017 , ... ... or dementia. However, many long-term care insurance companies have a waiver for care if ... the 90-day elimination period, when the family pays for care, is often waived, so ...
(Date:10/13/2017)... ... , ... Yisrayl Hawkins, Pastor and Overseer at The House of Yahweh, has ... least understood books in the Holy Scriptures, Revelation. The Book of Revelation paints a ... centuries. Many have tossed it off as mere rubbish, but Yisrayl Hawkins says that ...
(Date:10/13/2017)... ... 13, 2017 , ... “America On The Brink”: the Christian history of the ... is the creation of published author, William Nowers. Captain Nowers and his wife, ... he spent thirty years in the Navy. Following his career as a naval ...
(Date:10/12/2017)... ... October 12, 2017 , ... The company has ... today’s consumer and regulatory authorities worldwide. From Children’s to Adults 50+, every formula ... the highest standard. , These products are also: Gluten Free, Non-GMO, Vegan, ...
(Date:10/12/2017)... ... October 12, 2017 , ... Information about ... intend to develop to enable prevention of a major side effect of chemotherapy ... especially in pediatric patients. For cisplatin, hearing loss is FDA listed on-label as ...
Breaking Medicine News(10 mins):
(Date:10/2/2017)... , Oct. 2, 2017  AllianceRx Walgreens Prime, ... formed by Walgreens and pharmacy benefit manager Prime Therapeutics ... new brand, which included the unveiling of new signage ... , as well as at a few other company-owned ... new brand to patients, some of whom will begin ...
(Date:9/27/2017)... -- Commended for their devotion to personalized service, SMP Pharmacy Solutions ... in the South Florida Business Journal,s 50 Fastest-Growing Companies, and ... the national specialty pharmacy has found its niche.  To that ... be honored by SFBJ as the 2017 Power Leader in ... receive his award in October, Bardisa said of the three ...
(Date:9/22/2017)... -- As the latest Obamacare repeal effort moves is debated, ... and Lindsey Graham (R-SC) medical device market ... is in an odd place.  The industry wants repeal ... on medical device sales passed along with the Affordable ... visits and hospital customers with the funding to invest ...
Breaking Medicine Technology: