Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New avenue of HIV damage found

10.10.2002


Researchers at the University of Minnesota have discovered a new process by which HIV damages the immune system. They demonstrated that the portion of lymph nodes called the T cell zone is significantly damaged by chronic inflammation, which causes fibrosis. This is important because the T cell zone is where a significant portion of the human immune response occurs. The finding of accumulation of scar tissue in this portion of the lymph node may explain why aggressive anti-retroviral therapy (ART) does not improve the immune system in some people with HIV-1 infection. The study findings will be published in the Oct. 16, 2002, issue of the Journal of Clinical Investigation. The paper can be found at www.jci.org.



"HIV infection ultimately depletes the body of CD4 T cells, making it impossible to mount an immune response," said Timothy W. Schacker, M.D., associate professor of medicine and author of the study. "For the first time, we show that one mechanism of this depletion is damage to the structure that these cells need to maintain a normal-sized population and to mount an immune response to other infections. In essence, the T cell home is destroyed."

Researchers enrolled 11 individuals at various stages of HIV/AIDS infection. Their goal was to understand the specific changes that happen in the population of cells most directly affected by HIV--the CD4 T cells. These cells are responsible for coordinating the immune response and are the primary target for HIV infection and replication. Researchers biopsied and examined the lymph node tissue before and during treatment for HIV. They have developed sensitive methods to precisely measure both the size of the CD4 population in lymphatic tissue and the amount of scar tissue accumulated in the T cell zone.


Researchers noted two significant findings. First, the size of the CD4 T cell population measured in peripheral blood (commonly done to stage the disease and determine the effects of treatment) does not accurately reflect the size of the population in lymph tissues. "You could have a reasonable peripheral count and a very poor count in lymph tissues," said Schacker.

Second, the amount of fibrosis and scar tissue in the T cell zone was significantly related to the size of the CD4 population in that space (i.e. the more scar tissue, the fewer cells) and the recovery of the CD4 population with therapy. The researchers suggest the process of destruction is analogous to what is seen in chronic active hepatitis.

"We knew that T cells are destroyed by direct viral replication," said Schacker, "but we now know that the population is unable to recover to a normal size because the environmental niche used to support the cells is destroyed. New CD4 T cells are unable to get into the space they need to be in to function, and there is no space for the cells to divide."

One implication of this discovery is that through testing of the lymph nodes (similar to what is done to stage cancer), physicians might accurately stage the disease and predict the response to standard therapies.

"This is essentially a new concept in how HIV infection causes damage to the human immune system," said Schacker. "Our observation may explain why up to 25 percent of people placed on HIV therapy may have good viral suppression but still have no significant increase in T cell count.

"Currently, most treatment strategies for HIV/AIDS focus on stopping the virus from replicating itself in the body, which is essential to begin the process of immune reconstitution, but it does not happen for everyone. These findings suggest that therapies targeting the damage from inflammation and accumulation of scar tissue might enhance current antiviral therapy."

Deane Morrison | EurekAlert!
Further information:
http://www.umn.edu/

More articles from Health and Medicine:

nachricht Organ-on-a-chip mimics heart's biomechanical properties
23.02.2017 | Vanderbilt University

nachricht Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>